The Glass Bookshelf

For your enjoyment I have gathered together details of well over a hundred old books that relate to glass in some form or another, all of which are easily accessible over the Internet.

Whether it’s the glass sands of Kentucky, glass manufacture, glass painting, old trade catalogues, collecting glassware, making laboratory glassware, old Church windows or one of the many other strange topics relating to glass, there’s surely something for you somewhere in the list. I hope you find something that tickles your fancy.

Downloadable Book Lists

Although you’ll find the book list below within this blog I’m sure that some of you will want to “do your own thing”. So, I’ve created three alternative files that you can download and fiddle with. You could then sort your copy of the book list by title, date or author, improve the topic lists, add more books, or whatever else you might fancy doing. Make the downloaded files your own personalised bookshelf!

Beware: Although the file names below have familiar file types like “.doc” and “.pdf”, they aren’t what they seem to be. I’ve had to do some simple “trickery” to enable you to download file types that WordPress, in its infinite wisdom, has chosen not to allow. So, be sure to read the text that follows the filenames before downloading them!

  • Bookshelf-rtf.doc   Actually this is not a “.doc” file, it’s a “.rtf” file. I had to rename it from “Bookshelf.rtf” to “Bookshelf-rtf.doc” before WordPress would to allow me to share it with you. So, please rename it back to “Bookshelf.rtf” once you’ve downloaded it. Let me explain… Unlike “.doc” files, “.rtf” rich text files are Microsoft’s only official “portable” file format for word processing documents. This means it can be loaded into many kinds of word processor applications and not just Microsoft Word. Use this file if you want to maintain and use the book list within your word processor. If this doesn’t work for you then try the Bookshelf.xls file format in your spreadsheet application and copy the table out of there into your word processor application.
  • Bookshelf.xls   This spreadsheet file really is an “.xls” file and it is saved in an old version of Microsoft Excel format so you don’t need Microsoft’s latest and greatest bloatware to use this file. It should work with some other spreadsheet applications too.  Use this file if you want to maintain and use the book list as a spreadsheet. If this doesn’t work for you then try the Bookshelf.tsv file instead (see below).
  • Bookshelf-tsv.pdf   Actually this is not a “.pdf” file, it’s a “.tsv” file. I had to rename it from “Bookshelf.tsv” to “Bookshelf-tsv.pdf” before WordPress would to allow me to share it with you. So, please rename it back to “Bookshelf.tsv” once you’ve downloaded it. This is a “tab separated variable” file that can be loaded into most kinds of spreadsheet application, word processors and even some database applications. Treat this as your “last chance” file format because you’ll probably need to do some messing about to get what’s loaded into a nice useful state. Despite this it’ll be much quicker than trying to type everything manually.

If you struggle and fail with all three file formats, or have a particular need for some other file format for use on something other than a Microslop Windoze machine then do let me know and I’ll try to help.

Some Notes

The Title, Author and Date columns should uniquely and correctly identify each book but in some cases notes are added in square braces within the Title column to indicate something noteworthy, such as telling you that a different edition elsewhere in the table. Where a the title of a book title contains an ellipsis it is an indication that the full title was so long and verbose that it has been truncated. There were occasions when I reckoned the archive.org book details didn’t seem to be correct (for whatever reason) so occasionally you’ll find that information about titles, authors or dates in my table are not quite what you’ll find at archive.org.

The Topics column gives an indication of what kind of information is found in the books and can be rather vague. Sometimes I’ve given you what the archivist recorded as the topics, if anything. Sometimes I’ve added to their topic lists and sometimes I had to create the topic list myself. A consequence is that the list of topics can be rather erratic but better than a poke in the eye with a blunt stick.

The Location column contains one or more URL links that take you to a web page where you can download the book. It’s perhaps sad to note that many of the old books have been digitised multiple times whereas many other old books remain only as “hard copy”. After awhile I got bored with finding alternative sources for the books so stopped bothering.

In all cases, visiting the URL will reveal a download available in PDF format. Often there are other file formats available as well. Alternative formats might be more suitable for use on a Kindle or mobile phone, for example. If you intend to download a copy of all the books in PDF format then you will need about 4GB of free disk space.

Bear in mind that copyright laws in different countries are not the same. Distributing this list of books and their locations will not breach any copyright but distributing the scanned book images and expecting payment might.

Here are the books I’ve found so far. There are even more out there!

Oh, and sorry about the bad layout of the table. Despite messing around with the undelying HTML I can’t force WordPress to present the information tidily.

Title Author Date Topics Location
The Glass Worker, vol 4 no 46 (Jun 1907) and vol 4 no 48 (Aug 1907) Amalgamated Glass Workers’ International Association of America 1907 Glass Industry, Industrial https://archive.org/details/glassworker00amergoog
A Notable Collection of Ancient Egyptian, Greek and Roman Glass, Persian Potteries, Greek Painted Vases … Anderson Galleries Inc. 1924 Mr. Azeez Khayat, Catalogue https://archive.org/details/notablecollectio00ande
Stained glass of the middle ages in England & France Arnold, H. 1913 Glass painting and staining, Art, Mediaeval, England, France. https://archive.org/details/stainedglassofmi00arno and similar at https://archive.org/details/cu31924020532879
Arts and crafts essays

[in which many subjects are covered, including Stained Glass by Somers Clarke, pp96-105)

Arts and Crafts Exhibition Society 1893 Arts and crafts movement, Decorative arts https://archive.org/details/artscraftsessays00artsrich
History of the Worshipful Company of Glaziers of the City of London, otherwise the Company of Glaziers and Painters of Glass Ashdown, C. H. 1919 Company of Glaziers, London, Guilds. https://archive.org/details/historyofworshi00ashd
Twelfth Census of the United States: Census Bulletin no 228: Manufactures: Glass Manufacture Austin, S. P. 1902 Glass industry, Census https://archive.org/details/glassmanufacture00aust
The painter, gilder, and varnisher’s companion containing rules and regulations in everything relating to the arts of painting, gilding, varnishing, and glass staining … [See also 1867 edn] Baird, H. C. (Pub.) 1850 Painting, Industrial, Gilding, Varnish and varnishing, Receipts. https://archive.org/details/paintergildervar00phil
The painter, gilder, and varnisher’s companion containing rules and regulations in everything relating to the arts of painting, gilding, varnishing, and glass staining …, 10th Edn.

[See also 1850 edn]

Baird, H. C. (Pub.) 1867 Painting, Industrial, Gilding, Varnish and varnishing, Receipts. https://archive.org/details/paintergildervar01phil
Schwäbische Glasmalerei Balet, L. 1912 Glass painting and staining https://archive.org/details/schwbischeglas00bale
A Treatise on Painted Glass, Shewing its Applicablity to Every Style of Architecture Ballantine, J. 1845 Glass painting and staining https://archive.org/details/gri_33125012927634
American glassware, old and new: a sketch of the glass industry in the U.S. and manual for collectors of historical bottles Barber, E. A. 1900 Glass manufacture, Glassware https://archive.org/details/americanglasswar00barb
Spanish Glass in the Collection of the Hispanic Society of America Barber, E. A. 1917 Glassware, Spain https://archive.org/details/spanishglassinco00hisprich
English table glass

[See also later edition]

Bate, P. H. 1905 Glassware, Tableware, England https://archive.org/details/englishtableglas00bateuoft
English table glass

[See also earlier edition]

Bate, P. H. 1913 Glassware, Tableware, England https://archive.org/details/cu31924000434831
President’s Address on “Stained Glass and Painted Glass” , in Transactions of the Bristol and Gloucestershire Archaeological Society, Vol 22. Editor: Rev. C. S. Taylor, Bazley, G. S. 1899 Periodical. Antiquities, Bristol and Gloucestershire, Glass painting and staining. https://archive.org/details/transactionsbris22bris
Catalogue Belcher Mosaic Glass Co. 1886 Mosaics, Glass painting and staining, Glass, Coloured–Catalogues https://archive.org/details/catalog00belc
A lecture on stained glass Bell, R. 1922 Glass painting and staining https://archive.org/details/lectureonstained00bell
Sir Henry Bessemer, F. R. S. An autobiography

[Chapter VIII relates to glass processing]

Bessemer, H., Sir. 1905 Glass manufacture, Industrial processes, Autobiography https://archive.org/details/sirhenrybessemer00bessuoft
Elements of Glass and Glass Making Biser, B. F. 1899 Glass manufacture https://archive.org/details/elementsglassan00kochgoog
The Art of Glass: shewing how to make all sorts of glass, crystal and enamel, likewise the making of pearls, precious stones, china and looking-glasses … [Translation of: De l’art de la verrerie] Blancourt, H. 1699 Glass manufacture, Enamels & enamelling, precious stones, minerals, optical glass, glass eyes https://archive.org/details/gri_artofglasssh00haud
A handbook of laboratory glass‐blowing Bolas, B. D. 1921 Glass blowing and working, Glass manufacture, Technique https://archive.org/details/handbookoflabora02bolarich
A memoir on British resources of sands suitable for glass‐making Boswell, P. G. H. 1916 Glass manufacture https://archive.org/details/cu31924030703916
Japanese Enamels: With Illustrations from the Examples in the Bowes Collection Bowes, J. L. 1886 Enamels and enamelling, Cloissonné, Shippo, Japan https://archive.org/details/japaneseenamelsw00bowe
Notes on Shippo: A Sequel to Japanese Enamels Bowes, J. L. 1895 Enamels and enamelling, Glass manufacture, Cloissonné, Shippo, Japan https://archive.org/details/notesonshippoas00bowegoog
Glass cup plates: A Guide to Collectors Burns, C. 1921 Glassware https://archive.org/details/glasscupplatesgu00burn
Storied windows: A traveller’s introduction to the study of old church glass, from the twelfth century to the Renaissance, especially in France Bushnell, A. J. 1914 Glass painting and staining, Cathedrals, Renaissance, Mediaeval, France https://archive.org/details/storiedwindowstr00bush
Catalogue of the collection of stained and painted glass in the Pennsylvania museum Bye, A.E. 1925 Glass painting and staining, Philadelphia Museum of Art https://archive.org/details/catalogueofcolle00phil
General Electric Lighting Canadian General Electric Company 1949 Lighting, Glassware, Commercial & industrial equipment. https://archive.org/details/GeneralElectricLighting
Stories of Industry, 1891, Vol 1

[Vol 2 relates to clothing and foodstuffs]

Chase, A. & Clow, E. 1891 Industrial Arts, Minerals, Industrial Processes, Machinery & Equipment, Glass Manufacture, Pottery manufacture https://archive.org/details/storiesindustry00clowgoog
Art glass metals Chicago Metallic Sash Company 1925 Art glass, Came, Stained Glass, Glazing accessories, Trade, Catalogues https://archive.org/details/ArtGlassMetals
Five Black Arts: a popular account of the history, processes of manufacture, and uses of printing, pottery, glass, … Coggeshall, W. T. 1861 Printing History, Porcelain History, Glass Manufacture History, Iron Industry and Trade History, Gas Manufacture and Works History https://archive.org/details/fiveblackartspop00coggrich
The Crown Glass Cutter and Glazier’s Manual: Glass cutter, glazier & stained glass maker in ordinary to the king for Scotland Cooper, W. 1835 Glass manufacture https://archive.org/details/crownglasscutter00coop
Windows: A Book about Stained & Painted Glass

[See also later edition]

Day, L. F. 1897 Glass painting and staining https://archive.org/details/windowsbookabout00dayluoft and also https://archive.org/details/windowsbookabout00dayl
Windows: A Book about Stained & Painted Glass

[See also older edition]

Day, L. F. 1909 Glass painting and staining https://archive.org/details/windowsabookabou005427mbp
Catalogue of an Exhibition of Stained Glass from the XIth to the XVIIIth cent Demotte Inc. (Pub.) 1920 Glass painting and staining https://archive.org/details/catalogueofexhib00demo
Glass Dillon, E. 1907 Glass, Glassware https://archive.org/details/glass00dill
A history of English glass painting, with some remarks upon the Swiss glass miniatures of the sixteenth and seventeenth centuries Drake, M. 1912 Glass painting and staining https://archive.org/details/cu31924020532903
Valuable secrets in arts, trades, &c.: selected from the best authors and adapted to the situation of the United States [See also other editions] Duyckinck, E. (Pub.) 1802 Receipts, Workshop recipes, Industrial art, Art technique https://archive.org/details/valuablesecretsi00lond
Valuable secrets in arts, trades, &c.: selected from the best authors and adapted to the situation of the United States. [See also other editions] Duyckinck, E. (Pub.) 1809 Receipts, Workshop recipes, Industrial art, Art technique https://archive.org/details/valuablesecretsi00unse
Valuable secrets in arts, trades, &c.: selected from the best authors and adapted to the situation of the United States [See also other editions] Duyckinck, E. (Pub.) 1816 Receipts, Workshop recipes, Industrial art, Art technique https://archive.org/details/valuablesecretsi00newy
Ancient stained and painted glass Eden, F. S. 1913 Glass painting and staining, History https://archive.org/details/ancientstainedpa00edenuoft
The collection of heraldic stained glass at Ronaele Manor, Elkins Park, Pennsylvania, the residence of Mr. & Mrs. Fitz Eugene Dixon Eden, F. S. 1927 Dixon, Fitz Eugene, Glass painting and staining, Heraldry, Devices https://archive.org/details/collectionofhera00eden
Graeco‐Egyptian Glass Edgar, C. C. 1905 Ancient Glassware, Greco-Egyptian Glassware https://archive.org/details/graecoegyptiangl00edga
The Origin of Glass Blowing in American Journal of Archaeology, Vol XX, pp 134-143 Eisen, G. 1916 Glass blowing https://archive.org/details/jstor-497111
Antique Glass, in The Art Bulletin, Vol2: pp 87-119. Eisen, G. A. 1919 Glass painting and staining https://archive.org/details/jstor-3046352
Stained glass windows: An essay with a report to the vestry on stained glass windows for Grace Church, Lockport, New York Faber, W. F. 1900 Grace Episcopal Church (Lockport, N.Y.), Church records and registers, Glass painting and staining, Genealogy https://archive.org/details/stainedglasswind00fabe
Notes on the Painted Glass of Canterbury Cathedral Farrar, F. W. 1897 Canterbury Cathedral, Glass painting and staining https://archive.org/details/notesonpaintedgl00farrrich
Glass Manufacture and the Glass Sand Industry of Pennsylvania Fettke, C. R. 1919 Glass, Glass manufacture, Glass Sands, Pennsylvania https://archive.org/details/glassmanufactur00fettgoog and at https://archive.org/details/glassmanufacture00fett
The drama of glass [Publication date uncertain but there are references to 1893 within text] Field, K. 189‐ Glass manufacture https://archive.org/details/dramaofglass00fieliala
Hiersemanns Handbücher, Vol VIII: Handbuch der glasmalerei für forscher, sammler und kunstfreunde, wie für künstler, architekten und glasmaler Fischer, J. L. 1914 Glass painting and staining. https://archive.org/details/handbuchderglasm00fisc
Laboratory manual of glass‐blowing Frary, F. C. 1914 Glass Manufacture, Glass-Blowing, Scientific Glassware, Laboratory, Technique https://archive.org/details/laboratorymanua02frargoog
An Essay on the Art of Painting on Glass from the German of Emanuel Otto Fromberg Fromberg, E. O. 1851 Glass painting and staining https://archive.org/details/bub_gb_stgwMsChrJIC
Rudimentary Essay on the Art of Painting on Glass from the German of Emanuel Otto Fromberg Fromberg, E. O. 1857 Enamel and enamelling, Glass painting and staining, Glass manufacture chemistry https://archive.org/details/bub_gb_OVi2hv0g-x0C
Histoire de la Verrerie et de l’Émaillerie Garnier, E. 1886 Glass painting and staining, Enamel and enamelling https://archive.org/details/histoiredelaverr00garn
Street Lighting Glassware General Electric Company 1925 Street lighting, Glassware https://archive.org/details/StreetLightingGlassware
Metal Casements and Frames, Wrought Iron George Wragge Ltd. 1948 Steel windows, casement windows, Trade catalogue https://archive.org/details/MemorialsAndStainedGlassByGeorgeWraggeLtd.WardryWorksSalford
Rudimentary treatise on the art of painting on glass or glass-staining: comprising directions for preparing the pigments and fluxes … Gessert, M. 1851 Enamel and enamelling, Glass painting and staining https://archive.org/details/rudimentarytreat00gess and similar at https://archive.org/details/bub_gb_sS9uRkgM6xkC
A booke of sundry draughtes, principaly serving for glasiers … Gidde, W. 1615 Decoration and ornament, Glass painting and staining, Enamel and enamelling https://archive.org/details/bookeofsundrydra00gidd
Stained Glass and Metal Work of Every Description for Churches, Chapels, etc.: Catalogues, Photographs and Special Designs with… Gorham Manufacturing Co. 1895 Trade catalogue, Stained Glass, Art Glass, Ecclesiastical, Windows, Memorials, https://archive.org/details/GorhamMfgCoCCA22051
Le Vetrate di S. Francesco in Assisi – Studio Storico Iconografico Guisto, E. M. 1911 San Francesco Church (Assisi, Italy), Glass painting and staining https://archive.org/details/levetratedisfran00gius
Old English glasses. … glass drinking vessels in England, from early times to the end of the eighteenth century Hartshorne, A. 1897 Glassware, Great Britain, Old English Glass, Jacobite Glass, Irish Glass, Wine in England https://archive.org/details/oldenglishglasse00hart
An history of the origin and establishment of Gothic architecture : comprehending also … Hawkins, J. S. 1813 Cesare Cesariano, Glass painting and staining in Middle Ages, Gothic Architecture https://archive.org/details/historyoforigine00hawk
Rich cut glass and fine china Higgins & Seiter 1903? Trade Catalogue, Porcelain, Glass, Cut Glass https://archive.org/details/richcutglassfine00higg
General catalogue of the manufactures of Adam Hilger, Ltd Hilger, A. 1913 Wavelength Spectrometers, Optical instruments, Scientific instruments https://archive.org/details/Generalcatalogu00Hilg
Stained glass as an art Holiday, H. 1896 Glass painting and staining https://archive.org/details/stainedglassasar00holi
A practical manual of the collodion process : giving in detail a method for producing positive and negative pictures on glass and paper, ambrotypes, printing process, also patents… Humphrey, S. D. 1857 Collodion process, Collodion process, Photography, Photographic chemistry https://archive.org/details/practicalmanualo00hump
Invisible Glass Windows: A Dramatic New Merchandising Force

[An example of this can be seen in Byram Street, Huddersfield, West Yorkshire]

Invisible Glass Company of America 1937 Trade catalogue, Store front, Display window. https://archive.org/details/InvisibleGlassWindwoUnits
Encyclopaedia of chemistry, theoretical, practical, and analytical, as applied to the arts and manufacturers J. B. Lippincott & Co. 1877 Chemistry, Technical, Art, Manufacturing https://archive.org/details/b28127055_0002
Glass: Interesting Facts connected with its Discovery and Manufacture J. E. Caldwell & Co. 18?? Glassware, Trade Catalogues, Glass History, Cut Glass https://archive.org/details/glassinteresting00jeca
Priced and Illustrated Catalogue of Optical Instruments, Made, Imported and Sold, Wholesale and Retail James W. Queen & Co. 1870 Trade Catalogue, Optical Instruments, Lenses, Spectacles, Eye-Glasses, Telescopes, Camera Obscura, Microscopes, Dissection Tools, Biological Specimens, Geological Specimens https://archive.org/details/pricedillustrate00jamerich
Reminiscences of glass‐making, 2nd Edn. Jarves, D. 1865 Glass Manufacture, Glass History, Chemistry, Workshop, Recipes https://archive.org/details/reminiscencesofg00jarv
L’art de la Peinture sur Verre et de la Vitrerie Le Vieil, P. 1774 Glass painting and staining https://archive.org/details/gri_33125008683647
Valuable secrets concerning arts and trades

[Note: T. Hubbard is the publisher, not the author]

Leather, V. 1795 Decorative Arts https://archive.org/details/MAB.31962000740104Images and similar at https://archive.org/details/valuablesecretsc00leatrich
Department Store Mechandise Manuals: The Glassware Department Lehmann, M. A. 1918 Glassware, Glassware manufacture https://archive.org/details/cu31924014494219
Old glass and how to collect it

[See also later editions]

Lewis, J. S. 1900 Glass collecting, Glassware https://ia800500.us.archive.org/8/items/oldglasshowtoco00lewi/oldglasshowtoco00lewi.pdf
Old glass and how to collect it

[See also earlier edition]

Lewis, J. S. 1916 Glass collecting, Glassware https://archive.org/details/oldglasshowtocol00lewi
Old glass and how to collect it

[See also earlier editions]

Lewis, J. S. 1950 Glass collecting, Glassware https://archive.org/details/in.ernet.dli.2015.158144
Flat Glass Libbey‐Owens‐Ford Glass Company 1924 Glass, Glazing, Trade Catalogue, Glass manufacture https://archive.org/details/FlatGlass
Experimental Glass Blowing for Boys Lynde, C. J. 1920 Glass blowing and working, Laboratory https://archive.org/details/experimentalglas00lynd
Fifty years of glass making, 1869‐1919 Macbeth‐Evans Glass Company 1920 Glass Manufacture https://archive.org/details/fiftyyearsofglas00macbuoft
Glass and glass manufacture Marson, P. 1919 Glass, Glass manufacture https://archive.org/details/glassglassmanufa00mars
Optical measuring instruments, their construction, theory, and use Martin, L. C. 1924 Optical Instruments, Optical devices, Optics, Engineering https://archive.org/details/opticalmeasuring00mart
American glass McClinton, K. 1950 Glassware https://archive.org/details/amerglass00mccl
Les Vitraux Merson, O. 1895 Glass painting and staining https://archive.org/details/lesvitraux00mer and also at http://library.si.edu/digital-library/book/lesvitraux00mer
Fifteenth-Century Glass in The Chancel Window of St. Peter Mancroft, Norwich Meyrick, F. 1911 St. Peter Mancroft Church (Norwich, England), Glass painting and staining https://archive.org/details/fifteenthcentury00meyr
Stained glass Miller, E. 1900 Glass painting and staining https://archive.org/details/stainedglass00mill
Window Glass in the Making: An Art, A Craft, A Business Monroe, W. L. 1926 Glass, Glazing, Industrial Arts https://archive.org/details/WindowGlassInTheMakingAnArtACraftABusiness
The secret of pictorial art, or Self instructor in painting on glass, china, satin, and paper … Morse, D. D. 1879 Decorative arts, Decoration and ornament, Painting, Drawing https://archive.org/details/secretofpictoria00mors
International Art Glass Catalogue: Art and bevelled glass in all its branches: church, memorial, society and domestic windows, Art Nouveau, prism, mitre beveled plate, leaded bevel, etc. [See also 1924 edition] Nat. Ornamental Glass Mfrs Assn of the US and Canada. 1914 Glass painting and staining, Catalogues, Trade catalogue, Art glass https://archive.org/details/internationalart00nati
Revised International Art Glass Catalogue: Art and bevelled glass in all its branches: church, memorial, society and domestic windows, Art Nouveau, prism, mitre beveled plate, leaded bevel, etc. [See also 1914 edition] Nat. Ornamental Glass Mfrs Assn of the US and Canada. 1924 Glass painting and staining, Catalogues, Trade catalogue, Art glass https://archive.org/details/InternationalArtGlassCatalogChurch
Ancient painted glass in England 1170-1500 Nelson, P. 1913 Glass painting and staining, England, Mediaeval. https://archive.org/details/cu31924020532929
A descriptive catalogue of the glass vessels in the South Kensington museum Nesbitt, A. 1878 Glassware https://archive.org/details/descriptivecata00sout
Glass Nesbitt, A. 1878 Glass, Glassware, History, Glass Composition https://archive.org/details/gri_33125007981893
Geschichte der Schweizer Glasmalerei Oidtmann, H., Dr. 1905 Glass painting and staining https://archive.org/details/bub_gb_gR-DAAAAMAAJ
Die Rheinischen Glasmalereien vom 12. bis zum 16. Jahrhundert, Erster Band Oidtmann, H., Dr. 1912 Glass painting and staining https://archive.org/details/dierheinischengl01oidt
Modern optical instruments and their construction Orford, H. 1896 Optics, Optical Instruments, Optical devices. https://archive.org/details/b21285986
Le Vitrail; Son Histoire, Ses Manifestations à Travers les âges et les Peuples Ottin, L. 1896 Glass painting and staining https://archive.org/details/levitrailsonhist00otti
The Arcana of Arts and Sciences: or Farmers’ & Mechanics’ Manual: containing a great variety of valuable receipts and useful discoveries… Parker, M., Dr. 1824 Formulae, Recipes, Receipts, Agriculture, Industrial Arts, Pigments, Dyes, Dyeing, Woods, Metallurgy, Stains, Varnish, Glass manufacture, Cements, Enamelling https://archive.org/details/gri_arcanaofarts00park
Curiosities of glass making: With details of the processes and productions of ancient and modern ornamental glass manufacture Pellatt, A. 1849 Glass manufacture, Anceint glassware, Technique https://archive.org/details/gri_33125008683704
The glass collector; A Guide to Old English Glass Percival, M. 1919 Glassware https://archive.org/details/glasscollectorgu1919perc
The amateur’s handbook of practical information for the workshop and the laboratory, 2nd Edn. Phin, J. 1879 Workshop, Laboratory, Recipes. https://archive.org/details/amateurshandbook00phin and at https://archive.org/details/amateurshandbook01phin
Glass, paints, oils and painters’ sundries Pittsburgh Plate Glass Company 1901 Trade Catalogue, Art materials, Glass, Ornamental https://archive.org/details/glasspaintsoilsp00pitt
Glass, Paints, Varnishes and Brushes: their history, manufacture, and use Pittsburgh Plate Glass Company 1923 Glass, Glazing, Mirrors, Plate glass, Leaded glass, Store front, Commercial furniture, Pittsburgh Plate Glass Company https://archive.org/details/GlassPaintsVarnishesAndBrushesTheirHistoryManufactureAndUse
Old Beauty in New Glass Pittsburgh Plate Glass Company 1930 Trade catalogue, Glass, Ornamental glass, Windows, Art glass, Stained Glass https://archive.org/details/OldBeautyInNewGlass
A treatise on the origin, progressive improvement, and present state of the manufacture of porcelain and glass Porter, G. R. 1832 Porcelain, Glass manufacture https://archive.org/details/treatiseonorigin00port and similar at https://archive.org/details/treatiseonprogre00portrich
The Rudiments of Mineralogy, 3rd Edn. Ramsay, A. 1885 Mineralogy, Rocks & Minerals https://archive.org/details/rudimentsminera00ramsgoog
The Glass Sands of Kentucky: A Detailed Report Covering the Examination, Analysis and Industrial Evaluation of the Principal Glass Sand Deposits of the State Richardson, C. H. 1920 Rocks & Minerals, Sand, Glass manufacture https://archive.org/details/glasssandsofkent00richrich
Glorious Glass at St. John’s Church, Gouda Rijksen, A. A. J. 1900 Sint Janskerk (Gouda, Netherlands), Glass painting and staining https://archive.org/details/gloriousglassats00rijk
Glass Manufacture Rosenhain, W. 1919 Glass manufacture https://archive.org/details/glassmanufacture00roseuoft
Vasily Kandinsky painting on glass (hinterglasmalerei) Anniversary Exhibition Rothel, H. K. 1966 Wassily Kandinsky, Glass painting and staining, Stadtische Galerie in Munich https://archive.org/details/vasilykandinskyp00rt
Structure and Kinetics of Glass Corrosion [D.Phil Dissertation] Sanders, D. M. 1973 Glass, Glass corrosion https://archive.org/details/structurekinetic00sand
La Verrerie depuis les Temps les Plus Reculés Jusqu’à nos Jours

[See also 1869 edn]

Sauzay, A. 1868 Glass, Glassware, Glass manufacture, Glass craft, Decoration and ornament, Glass painting and staining, Mirrors, Optical glass, Optical instruments, Eyes, Artificial, Glass beads https://archive.org/details/bub_gb_KepIAAAAIAAJ
La Verrerie depuis les Temps les Plus Reculés Jusqu’à nos Jours, 2nd Edn.

[See also 1868 edn]

Sauzay, A. 1869 Glass, Glassware, Glass manufacture, Glass craft, Decoration and ornament, Glass painting and staining, Mirrors, Optical glass, Optical instruments, Glass eyes, Glass beads, Pigments, Water colours, Cosmetics, Fabrics and dying, https://archive.org/details/laverreriedepuis00sauz
Wonders of Glass‐Making in All Ages Sauzay, A. 1870 Glass manufacture, Glassware https://archive.org/details/gri_33125001410634
Marvels of Glass‐Making in All Ages Sauzay, A. 1870 Glass, Glass manufacture https://archive.org/details/marvelsglassmak00sauzgoog
Handbook of the Glass Industry Scholes, S. R. 1941 Glass manufacture, Chemistry, Physics, Orton Cones, Recipes, Conversion tables, Commercial advertising https://archive.org/details/in.ernet.dli.2015.205644
Recipes for Flint Glass Making: being leaves from the mixing book of several experts in the flint glass trade…, 2nd Edn. Scott, Greenwood & Son (Pub.) 1907 Glass, Workshop recipes https://archive.org/details/recipesforflintg00lond
General Catalog 1911-1912

[Mostly wood-related]

Segelke & Kohlhaus Mfg. Co. 1912 Trade Catalogue, Wooden fittings, Wood windows, Commercial fixtures, Art glass, Stained Glass https://archive.org/details/GeneralCatalog1911-1912
The chemistry of the several natural and artificial heterogeneous compounds used in manufacturing porcelain, glass, and pottery

[Originally published 1837]

Shaw, S. 1900 Pottery, Chemistry, Technical https://archive.org/details/chemistryofsever00shawrich
The Methods of Glass Blowing ‐ For the use of physical and chemical students Shenstone, W. A. 1897 Glass blowing and working https://archive.org/details/methodsofglassbl00shenrich
The Methods of Glass Blowing, and of Working Silica in the Oxy‐Gas Flame: For the use of chemical and physical students [see also 1916 edn’ Shenstone, W. A. 1902 Glass blowing and working https://archive.org/details/glassblowing00shenrich
The Methods of Glass Blowing, and of Working Silica in the Oxy‐Gas Flame: For the use of chemical and physical students [see also 1902 edn’ Shenstone, W. A. 1916 Glass blowing and working https://archive.org/details/methodsofglassbl00shenuoft
Stained glass tours in France Sherrill, C. H. 1908 Glass painting and staining, Church buildings, Cathedrals, France, Travel https://archive.org/details/stainedglasstour00sherrich
Stained glass tours in England Sherrill, C. H. 1909 Glass painting and staining, Church buildings,Cathedrals, England, Travel https://archive.org/details/stainedglasstour00sher
A stained glass tour in Italy Sherrill, C. H. 1913 Glass painting and staining https://archive.org/details/cu31924024837159
Photography in a nut shell; or, The experience of an artist in photography, on paper, glass and silver, with illustrations. Simons, M. P. 1858 Photography, Photographic chemistry, Daguerreotype, Ambrotype https://archive.org/details/photographyinnut00simo
The Laboratory, or, School of Arts: Containing a large collection of valuable of secrets, experiments, and manual operations in arts and manufactures… Vol II, 6th Edn.

[See also Vol I]

Smith, G. 1799 Industrial Arts, Technology, Receipts, Recipes, Coins, Medals, Drawing, Painting, Gnomonics, Optics, Etching, Engraving, Paint pigments, Varnish https://archive.org/details/laboratoryorscho02smit
The Laboratory, or, School of Arts: Containing a large collection of valuable of secrets, experiments, and manual operations in arts and manufactures… Vol I, 6th Edn.

[See also Vol II]

Smith, G. 1799 Industrial Arts, Technology, Receipts, Recipes, Fireworks, Metallurgy, Glass making, Glass staining and painting, Metal casting, https://archive.org/details/laboratoryorscho01smit
Practical instructions in enamel painting on glass, china, tiles, etc … Snell, H. J. 1874 Glass painting and staining, China painting, Enamel and enamelling, Artists’ materials https://archive.org/details/practicalinstruc00snel
The golden cabinet : being the laboratory, or handmaid to the arts : containing such branches of useful knowledge, as nearly concerns all kinds of people, from the squire to the peasant, and will afford both profit and delight Spotswood, W. 1793 Chemistry, Technical, Industrial arts, Technical manuals, Formulas, Recipes, Gilding, Glass, Drawing, Dyes and dyeing, Japanning https://archive.org/details/gri_goldencabine00rice and similar at https://archive.org/details/MAB.31962000740062Images
Decoration of Metal, Wood, Glass, etc.: A book for manufacturers, mechanics, painters, decorators,… Standage, H. C. 1908 Workshop recipes, receipts, Metal, Glass https://archive.org/details/decorationofmeta00stan
Old Irish glass Stannus, G. 1921 Glassware, Irish https://archive.org/details/oldirishglass00stan_0
Procedures In Experimental Physics Strong, J. 1938 Experimental Physics, Laboratory, Glass blowing, Optics, Heat, Radiation, Vacuum, Moulding and casting https://archive.org/details/ProceduresInExperimentalPhysics
A Treatise on the Art of Glass Painting Suffling, E. R. 1902 Glass painting and staining https://archive.org/details/in.ernet.dli.2015.32480
Memorial windows Tiffany Glass & Decorating Co. 1896 Glass painting and staining, Favrile glass, Catalogues, Trade catalogues https://archive.org/details/memorialwindows00tiff
Tiffany Favrile Glass, Tiffany Windows, Tiffany Mosaics, Tiffany Monuments, Tiffany Granite [see also later edition] Tiffany Studios 1913 Catalogues, Mosaics, Glass painting and staining, Memorials, Sepulchral monuments. https://archive.org/details/tiffanyfavrilegl00tiff
Tributes to honor, suggested types of memorials by the ecclesiastical department of the Tiffany Studios. Tiffany Studios 1918 Catalogues, Glass paining and staining, Sepulchral monuments. https://archive.org/details/tributestohonors00tiff
Tiffany Favrile Glass, Tiffany Windows, Tiffany Mosaics, Tiffany Monuments, Tiffany Granite [see also earlier edition] Tiffany Studios 1922 Catalogues, Mosaics, Glass painting and staining, Memorials, Sepulchral monuments. https://archive.org/details/bml-NK5312_T44
Art in Glass: A guide to the glass collections Toledo Museum of Art 1969 Glass art https://archive.org/details/artinglassguidet00tole
Philological Studies in Ancient Glass

[1922 PhD Thesis]

Trowbridge, M. L. 1930 Greek language, Latin language, Classical literature, Glass Manufacture, Glass uses, Glass https://archive.org/details/philologicalstud00trow
On some Optical Peculiarities of Ancient Painted Glass, in Proceedings of the Clifton Antiquarian Club for 1884/88-1909/12, Vol 1, pp 207-216.

[Appears to be the same as the book of the same name]

Tuckett, F. F. 1888 Trademarks, Merchants https://archive.org/details/proceedings00glogoog
On some Optical Peculiarities of Ancient Painted Glass. Offprint from VClifton Antiquarian Club. Tuckett, F. F. 1888 Glass painting and staining, Medieval https://archive.org/details/onsomeopticalpec00tuck
Journal of the Society of Glass Technology, Vol IV Turner, W. E. S. (Ed) 1920 Journal, Technical, Glass Technology https://archive.org/details/journalglasstech04soci
Journal of the Society of Glass Technology, Vol V Turner, W. E. S. (Ed) 1921 Journal, Technical, Glass Technology https://archive.org/details/journalglasstech05soci
Journal of the Society of Glass Technology, Vol VI Turner, W. E. S. (Ed) 1922 Journal, Technical, Glass Technology https://archive.org/details/journalglasstech06soci
Journal of the Society of Glass Technology, Vol VII Turner, W. E. S. (Ed) 1923 Journal, Technical, Glass Technology https://archive.org/details/journalglasstech07soci
Chemical analysis for glassmakers: Containing methods of analysis for clays and other silicates which will be found useful for the pottery industry Uhlig, E. C. 1903 Glass manufacture, Chemical analysis, https://archive.org/details/gri_33125001407085
The glass industry. Report on the cost of production of glass in the United States United States Bureau of Foreign and Domestic Commerce 1917 Glass manufacture, Industry, Glass industry https://archive.org/details/glassindustryrep00unit
Information Concerning Optical Glass and Chemical Glassware United States Tariff Commission 1919 United States, Glassware, Glass manufacture, Optical glass, Trade Tariffs https://archive.org/details/infoopticalglass00unitiala
Notice historique sur les Peintres-Verriers d’Anvers du XVe au XVIIIe Siècle van Cauwenberghs, C. 1891 Glass painting and staining https://archive.org/details/noticehistorique00cauw
University of Illinois Engineering Experiment Station Bulletin No. 118, December 1920, Dissolved Gases in Glass Washburn, E. W., Footitt, F. F. and Bunting, E. N. 1920 Glass manufacture, Glass chemistry https://archive.org/details/dissolvedgasesin00washrich
Report on the Manufacture of Glass Weeks, J. D. 1883 Glass Manufacture, Glass-working, Glass composition, Report, Statistics, 1880 Census, United States, https://archive.org/details/reportonmanufact00unit
Stained glass; a handbook on the art of stained and painted glass, its origin and development from the time of Charlemagne to its decadence (850-1650 A. D.) Werck, A. 1922 Glass painting and staining, Mediaeval, Art https://archive.org/details/stainedglasshand00werc
Irish Glass: An account of glass‐making in Ireland from the XVIth century to the present day Westropp, M. S. D. 1920 Glass, Glass manufacture, Ireland https://archive.org/details/irishglassaccoun00westuoft
Stained glass work: a text-book for students and workers in glass.

[part of The Artistic Crafts Series of Technical Handbooks, ed. W. R. Lethaby]

[See also 1905 edition’

Whall, C. W. 1920 Glass painting and staining, Glass manufacture, Technique https://archive.org/details/stainedglasswo00whal and similar at https://archive.org/details/stainedglasswork00whaluoft and at https://openlibrary.org/books/OL7250574M/Stained_glass_work
Stained glass work: a text-book for students and workers in glass

[part of The Artistic Crafts Series of Technical Handbooks, ed. W. R. Lethaby]

[See also 1920 edition]

Whall, C.W. 1905 Glass painting and staining, Glass manufacture, Technique https://archive.org/details/stainedglasswor00whalgoog
A concise account of the principal works in stained glass that have been executed Willement, T. 1840 Glass painting and staining — Great Britain https://archive.org/details/conciseaccountof00williala
William Morris & Compy (Ruskin House) Ltd William Morris & Co. 1910 Windows, Glazing, Glass, Stained Glass, Casement windows, ornamental metals, Trade Catalogue https://archive.org/details/WilliamMorrisCompy.ruskinHouseLimitedManagingDirectorMr.William
Notes on the development of the ruby color in glass in University of Illinois Bulletin Vol XI No. 23, 30 July 1914 Williams, A. E. 1913 Glass, Glass chemistry, Ruby https://archive.org/details/notesondevelopme00willrich
An inquiry into the difference of style observable in ancient glass paintings: especially in England: With Hints on Glass Painting, Vol. 1

[See also Vol 2]

Winston, C. 1847 Glass painting and staining https://archive.org/details/inquiryintodiffe00wins and similar at https://archive.org/details/inquiryintodiffe01wins and at https://archive.org/details/gri_33125001141833
An inquiry into the difference of style observable in ancient glass paintings, especially in England with hints on glass painting, Vol. 2

[See also Vol 1]

Winston, C. 1847 Glass painting and staining https://archive.org/details/inquiryintodiffe02wins and similar at https://archive.org/details/gri_33125001141841
Memoirs illustrative of the art of glass painting Winston, C. 1865 Glass painting and staining https://archive.org/details/memoirsillustrat00wins and similar at https://archive.org/details/memoirsillustra00wins
One Thousand Valuable Secrets in the Elegant and Useful Arts, Collected from the Practice of the Best Artists, and … Woodward, W. W. 1795 Receipts, Recipies, Art materials, Cooking, Industrial Arts, Formulae, Engraving, Metallurgy, Varnish, Glass Manufacture, Glass painting, https://archive.org/details/gri_onethousandv00bdav
The Manufacture of Optical Glass and of Optical Systems: A war-time problem Wright, F. E. 1921 Optical instruments, Optical glass, Glass manufacture https://archive.org/details/manufactureofopt00unitrich
Manual of Laboratory Glass Blowing Wright, R. H. 1943 Glass Blowing, Technique https://archive.org/details/in.ernet.dli.2015.212232
Collecting old glass: English and Irish Yoxall, J. H. 1916 Glass collecting, Glassware https://archive.org/details/collectingoldgla00yoxa

Well that’s all folks. Happy reading!

Advertisements
Posted in Books | Tagged | Leave a comment

Thickening Glastac

Today I want to have a short chat about my experiences with Bullseye’s Glastac and some experiments with using CMC to thicken it. There’s no rocket science. I simply though you might enjoy another way to make use of your CMC.

Background

If you’re a glass fuser you’ve probably used Glastac. If you haven’t I recommend you try it.

Glastac is a deliberately weak glue and in my experience it cleanly burns away in a kiln. It is useful because you can glue together the component parts of your glass masterpiece with the certain knowledge that you can re-place the parts for quite a long time. Better still, it helps to ensure your masterpiece will not fall apart when you are moving it to your kiln.

As an aside, I caution against using white PVA glues, such as the oft-recommended Elmer’s Glue. Although I do use PVA glues occasionally, I have noticed that it does not always cleanly burn away and that it can cause damage to a glass surface. I particularly notice this when an excess of PVA is used. But I digress.

The only problem I have found with Glastac, particularly when used in excess, is that surface tension sometimes drags small pieces of glass away from where I put them. Using less Glastac helps avoid this problem but the converse situation is that sparing use of Glastac means that the small pieces of glass are not sufficiently glued to stay put.

And then I noticed that Bullseye had introduced Glastac in a gel form. Hmm. Thinks. Can I find the Manufacturer’s Safety Data Sheet (MSDS) to find out how it differs from the “old fashioned” Glastac? No, so it’s time to just experiment.

Avid readers amongst you will remember that I’ve chattered about carboxymethylcellulose (CMC) on a number of occasions. Most of my chatterings were in Squirt Your Frits but I’ve also mentioned it in passing in other places such as converting ordinary safety flux into a gel form over at Make Your Own Safety Flux.

This made me wonder if a little CMC gloop would thicken “old fashioned” Glastac and make it even better.

Thickening Your Glastac

dscf3558-glastacInstructions on where to find CMC, what it is, how it works and how to make your own CMC gloop is covered in plenty of detail over in my Squirt Your Frits blog. I will not repeat all this information so read that blog and come back again if you need to. I will however show you pictures of a bottle of Glastac and (lower down) a little 100 gram pot of CMC sold under the “Tylo” brand name typically bought by sugar crafters.

Making your own substitute for Bullseye’s Glastac Gel is a simple matter of thickening up some “old fashioned” Glastac with CMC. However the devil is, as they say, in the detail.

I found it most convenient to start by making up some “sloppy” sol-phase CMC gel. The exact consistency does not matter. All you are aiming for is a CMC gel that is thick but flows reasonably slowly when you tip the container.

dscf3555-cmc-potNext, you need to find another little container and add some Glastac to some CMC gel and give it a thorough mixing. If the outcome is too thick, either add some more Glastac or add some water. If the outcome is too runny add some more CMC gel.

As to the exact proportions of Glastac and CMC gel I can only report that making numerous little batches with differing proportions didn’t make seem to make any noticeable difference. As long as there’s a reasonable amount of Glastac in the mixture it’s going to be a glue. As long as there’s some CMC gel in the mixture it’s going to be thicker.

What could be simpler than that?

Speedy Gel?

In an attempt to make the homemade substitute dry quicker I tried using propanol in place of some of the water.

There’s nothing special about propanol (also known as isopropyl alcohol). It’s just an industrial alcohol  that is widely used as a solvent and as such it’s also useful for cleaning glass. Having said that, I mostly use acetone for cleaning glass.

However, unlike the ethanol (also known as ethyl alcohol) in your booze, it’s not safe to drink. Here in the UK I buy it from APC Pure rather than from glass suppliers simply because it’s much cheaper and they’re relatively local. I’m not connected with APC Pure other than being a customer. And once again, I digress…

I didn’t notice any adverse effects of using this modified mixture other than the smell of evaporating propanol. I can’t really say that I noticed the glue drying noticeable quicker but to be fair I wasn’t conducting a proper controlled experiment against a stopwatch.

So, I leave you with the thought that using an alcohol, such as propanol, should quicken the rate at which the glue dries but no convincing practical evidence. This is a prompt for you to continue the experiment and tell me!

Homemade Glastac Gel In Use

Although I have not compared this homemade Glastac gel mixture with the genuine  Bullseye’s Glastac Gel I can at least tell you that I’ve had good results with the homemade substitute (with or without adding alcohol).

The homemade mixture still works as a weak glue. The improvement is that it no longer seems to cause little glass pieces to slide and shift as the glue dries. Other advantages are that it’s quick, easy and cheap to produce in small quantities and you don’t need to find more space for yet another bottle of glue.

If you find your homemade Glastac gel mixture works well you might consider buying some of the real Glastac Gel. At the worst it’s going to be no better. At best it’ll be even better.

Shelf Life

I found that leaving a small open pot of my homemade Glastac Gel substitute lying around for several weeks resulted in an “infection”. The feint tint of green near the surface leads me to suspect the beginnings of algal growth. Maybe I’ve discovered a new balanced diet for bugs. Hmm.

But all is not lost. Simply make up your homemade Glastac gel mixture in small quantities when you need some.

This does not mean you have to make up the CMC gel in small quantities. There is a shortcut. You may recall that I’ve already mentioned in Freeze Your Frits that your CMC gloop will freeze successfully. Store your excess in the freezer and make use of it a little at a time.

 

That’s all folks.

Posted in CMC, Experiment, Glastac, Tylo | Tagged , , , | Leave a comment

Shake Your Globs

If my early chattering about making globs from scraps of ordinary stained glass in Recycling Scraps of Stained Glass and with fusing glass at Waste Not Want Not have inspired you to make your own then maybe today’s blog will be of some interest. But only if you also do copper-foiled “Tiffany” style work.

Reducing waste and saving the planet is a good ethic, but what’s the point if you don’t make use of them?

I previously mentioned that kids enjoy collecting the recycled glass globs and that sometimes they can be used for pieces of jewellery too. Also, if you live in the land of deliberate bad spellers you might consider making jewelry with them instead.

Today’s theme is all about making use of recycled globs in your copper-foiled “Tiffany” style work.

Grind Before Foiling

Wrapping copper foil around a glob is a rather fiddly process. Not only is it a curved surface but it’s also rather smooth and slippery. The simple answer to this problem is to grind the edges of the globs so that you have a roughened surface against which the copper foil sticks more easily. Grinding can also be used to subtly re-shape a glob that has a defective or irregular shape.

Once you have wrapped the globs with copper foil you’ll want to burnish the copper foil and make the globs ready for soldering. Use your fingers to gently push-in the upper and lower edges of the copper foil but do not waste too much time on this. All that you need to achieve is a crinkly edge that needs the burnishing “finished off” by a method that is less fiddly and more efficient than using a fid or Allnova tool.

Burnishing the Foil

A simple and effective way to complete the burnishing process is to put your foiled globs into a jar with some un-foiled globs, put the lid on the jar, then shake until the burnishing process is complete. This trick is something I read on a forum years ago. So long ago that I don’t recall where or when. There’s no credit due to me for this burnishing method but I can at least recommend it.

dscf3492-globs-and-jarOn the right you’ll see a picture of a “half pound” jar, some un-foiled globs and some foiled globs. Notice the relative quantities being used. Notice that the foiled-globs still have crinkly edges to their copper foiling.

The number of un-foiled globs to use is not critical. It partly depends on the size of the jar just as it depends on how many foiled-globs are to be burnished. Too many globs in the jar means there’s not enough space for the globs to do their burnishing task. Too few globs in the jar means fewer impacts resulting in a slower burnishing process.

dscf3498-foiled-globsYou need to stop shaking as soon as the copper foil is burnished, otherwise the burnishing gets over-done and the copper foil starts to peel away from the globs. The picture on the right shows you the same foiled globs after burnishing. Good, eh?

This noisy task is enjoyed by children but do bear in mind that child labour (labor) is likely to result in over-shaken globs because they are more interested in the noise than the degree of burnishing. To mitigate this problem, reduce the number of un-foiled globs (or maybe eliminate them) so that the burnishing process is slower, thus extending their acceptable period of fun and enjoyment.

Using the Foiled Globs

You might think that there’s nothing more for me to say about how to use some copper-foiled glass. But you’d be wrong. If writing some more means there’s less time for housework then I’m not going to be deterred.

The privileges of childhood include the latitude to do stupid things like stuff small things up noses or in mouths. So, here’s an example of how I tend to use under-sized globs. Incidentally, it’s also a way by which I make use of the irregular shaped rectangles that we produce when squaring-off a wonky ends of newly purchased sheets of glass that were not accurately cut by the supplier.

dscf1719-glob-use-1In this picture you see a small area of a finished abstract piece of copper-foiled work, the design of which is motivated more by the use of scrap glass than intentional artistry. Of greater note in consequence of the theme of this posting is the use of foiled globs. Of incidental interest is the use aforementioned irregular-shaped strips of glass that tend to arise from “squaring-off”.

You can see that this particular example is not random. It may be a “sort-of rainbow” but in other pieces I arrange the globs such that they “sort-of flow” down through “sort-of cracks” between the irregular glass strips in the manner of “sort-of fractured rock”. Notice also that I’ve left a big hole (negative space) in the design. I also try to introduce excitement and interest by using different textures, differing opacity, slipping in a slice of agate or messing around with incomplete patination. Sometimes the best results come from not thinking too much!

dscf2414-glob-use-2My second example is what can be done when you have a huge excess of globs and can’t bear to throw them out. From the picture you’ll see one end of a “box of bubbles”. Just like the previous example I’m using both flat glass, foiled globs and leaving some holes. Incidentally, have you noticed that I chose a Wissmach hammered green border glass to reinforce the “blobby” nature of the interior of the panel?

There are two problems with this kind of panel. The first is that it can use up an awful lot of lead solder and the panels can get very heavy as a consequence. The second is that it’s very time consuming to make. So don’t make these panels too large and don’t expect to recover the real cost of making them if you intend to sell them!

My final comments relate to the technical matter of soldering thick globs into a panel made with thinner glass. You will no doubt realise that the sheet glass will be about 3mm thick but the globs might be 6mm. So, the globs will tend to “stick out” at the front.

If you want your globs to “stick out” only on the front of the panel then simply lay out the pieces front-side uppermost and get soldering without further ado. As an alternative you might try using thick card scraps underneath the plain glass pieces which then allows the globs to “sink” backwards into a more balanced and less proud form.

Concluding Remarks

So, there you have it. A couple more ways to save the planet by making use of recycled glass globs and a simple but effective way to burnish the copper foil onto globs.

A mercifully short blog and not one hint of maths or science. Aren’t you the lucky ones?!

Happy shaking and a happy (though belated) New Year.

Posted in Copper-foiled, Recycling | Tagged , | Leave a comment

Make Your Own Glassline Paper

Today’s chatter is for glass fusers and is about Glassline Paper. I’ll discuss how and why you might make your own, either because Glassline don’t produce exactly what you want or because you have the time and inclination to make a relatively inexpensive equivalent.

I don’t think I’ve inflicted mathematics onto you in previous blogs so now’s my chance. I hope to show you that mathematics (and the scientific method) can sometimes be useful, even when you’re not a mathematician or scientist.

Some Background

If you’re not familiar with Glassline products then a visit here will put you in the picture. Today we’re interested in the Glassline Paper and Glassline Pen products. I don’t often use them myself but there are times when they’re useful.

dscf3548-glassline-paper-examplesGlassline papers are available in a variety of colours, patterns, textures and sizes. Here’s a picture of a small selection of examples. You’ll find more examples at Glassline’s online shop here and summarised here in a single page. Both links contain information about how to use the Glassline papers.

As noted in those two links, Glassline Pens can be used to draw directly on Glassline Paper and I’ll come back to this little fact later when I talk about making your own papers. You can see a colour chart here and you will see the variety of standard colours is not large – but you can mix the colours if you wish.

Something worth mentioning for the benefit of novices is that Glassline Pens aren’t pens. They’re flattish bottles of coloured materials that can be fired and you can buy “stick-on” tips so that the bottles can be used as “squirty pens”. As is my habit, I refer you to the Manufacturer Safety Data Sheet (MSDS) page to find out what materials produce which colour and the all-important advice about how to safely use them. Potters amongst you will notice similarities with materials used in glazes.

dscf3554-glassline-pen-examplesThe picture opposite shows you a couple of example Glassline Pen bottles. Although you can also use a paint brush, an airbrush or whatever else takes your fancy, today we’re only interested in these Glassline Pens in one context – as the colourant for Glassline Papers.

Incidentally, Glassline only quote temperatures in Fahrenheit. For future reference, 1500°F is about 816°C and 1000°F is 538°C and you shouldn’t worry if you want to round off the numbers.

Now that you’re familiar with Glassline Pens and Glassline Papers, we’re ready to continue

An Accidental Discovery

It is quite some time since I discovered you can put Bullseye thinfire paper between layers of glass. I don’t think I ever remembered to mention this in past blogs so I now apologise and hint that this turns out to be part of what lies behind today’s discussion.

More recently I decided to buy a few Glassline Pens and a few small packs of Glassline Papers so that I could experiment with them. Until recently most of the packs of Glassline Paper remained unopened as I rarely find a use for them and have only spent a little time experimenting with them.

dscf3560-glassline-paper-logoOne of the packs of Glassline Paper I opened last week came with a surprise discovery. I noticed that the obverse (back) of the papers had the familiar logo and markings of Bullseye Thinfire paper. Previous papers did not have the Bullseye Thinfire markings. The picture opposite shows what I mean. Three sheets out of twelve identifying their origin doesn’t sound random to me so I was left wondering if Glassline didn’t intend to  reveal what their papers were made from. This is something we will test statistically in the next section.

A final realisation was that the Glassline Paper is coloured with what looks like and what feels like Glassline Pen colourants. This is hardly surprising when you remember that Glassline tell us that we can use Glassline Pens on Glassline Paper.

Mathematics is Fun

If the papers being used at the Glassline factory were unpacked and stacked randomly then we might expect half to be plain-side up and half plain-side down. If Glassline are trying to hide the fact that they use Bullseye Thinfire paper, in an attempt to obscure how their products are made, we’d expect Glassline to deliberately stack their Thinfire paper the same way so that the plain side ends up on the backs of their Glassline Paper, covering the Bullseye logo and markings with the colourants.

I have 12 sheets of Glassline Paper so would expect to see the Bullseye logo at the back of about 6 sheets if Glassline doesn’t care which way up they use the Thinfire paper. As already mentioned, I observed just 3 out of 12 having the logo on the back. If this is deliberate bias then it would be interesting to find out more and the Chi-squared test is how we find out.

For our statistical test we need to confirm (or reject) our “null hypothesis” that 3 out of 12 is statistically no different to 6 out of 12.

If that sounds daft to you, ask yourself these next two questions. Ask yourself “how many children of the same gender can a family have before we decide something weird has been happening” and ask yourself “how many times you can flip a coin and get the same result without getting worried that there’s something wrong with your coin”.

But I digress…

We start our Chi-squared test with some calculations based on observed (O) and expected (E) results. We have 12 samples, 3 of which have a logo on the back…

Paper Side         O         E          O-E     (O-E)2  (O-E)2/E

Back is plain      9          6          3          9          1.5

Back has logo   3          6          -3         9          1.5

We add up the two numbers at the right to get 3.0 and this is our Chi-squared value.

We now need to think about “degrees of freedom” because laying a sheet of paper (or flipping a coin) involves the freedom to do something that causes something to happen.

Should we decide to lay a sheet of Thinfire with the plain side upwards then we automatically know that the only other possibility is to have had the plain side downwards. Notice that we had two possible options and that choosing one of them automatically determines what the eliminated alternative was. So, two options gives us just one “degree of freedom” to choose. Therefore 1 is the degree of freedom we need for our Chi-squared test.

Looking at a Chi-squared table in the row for 1 degree of freedom we find 3.0 is a Chi-squared value that lies somewhere between the columns headed with 0.10 and 0.05. These two column headings are upper and lower bounds on the probability we’re looking for. These numbers can be represented in more familiar ways. Instead of 0.10 you could say 10% or 1 in 10. For 0.05 you could say 5% or 1 in 20.

Therefore, in human-speak, the 0.10 and 0.05 mean that 3 out of 12 sheets of Thinfire paper with their plain side upwards will happen somewhere between 10% and 5% of the time when we do our “sampling”. These are quite large probabilities which means our null hypothesis (that there is no difference) is probable. The corollary is that our original hypothesis is not probable. If our original hypothesis is not probable then Glassline aren’t trying to hide the fact they’re using Bullseye Thinfire paper and are therefore not actively using the Thinfire paper one way or the other.

Therefore, based on my small sample of 12 pieces of Glassline Paper, 3 out of 12 is no different than 6 out of 12. The same would apply to 9 out of 12.

If the whole concept of 3 out of 12, or 9 out of 12, being no different than 6 out of 12 has your intrigued or stunned, I challenge you to analyse some of the statistics behind advertising claims you’ll see on TV or the statistics being quoted by governments or other official bodies. Often you’ll discover the claims are being made on the basis of customer preferences, responses or equivalent measures that are not statistically valid. Knowledge is power.

If all that babble left you realising you’ve forgotten all your mathematics then here is where you can revise your Chi-squared test. It’s also where you can find a Chi-squared value table.

Making Your Own

And at long last we come to the most important part of my chatter – telling you what Glassline Paper is made of and how you might make your own equivalent papers.

All you need to make your own is Bullseye Thinfire paper, some Glassline Pens and a method of production.

There are many methods by which you can apply the colour to the papers. Some of them are mentioned by Glassline. You might use a paintbrush, sponge pad, an airbrush or whatever else comes to mind. Sometimes you may wish to add water to make a thinner mixture, especially when you want to use an airbrush or want to produce a paler tint.

Remember also that Glassline tell us that we can use Glassline Pens to decorate their Glassline Papers.

dscf3561-glassline-overspillAlthough Glassline Paper tends to have colouring on one side, you will notice in the picture opposite that some papers have overspill on the reverse side.  I don’t suppose Glassline care about this overspill beyond recognising it means they’re using more colourant than they’d like to. For us, it means we have to buy papers that are neither single-sided nor double-sided. But bluntly, the backs are an untidy mess. I don’t like mess and it detracts from the quality of what we try to achieve with out work.

dscf3551-glassline-heart-2dscf3551-glassline-heart-1In these two pictures, on the left and right, you can see that it is possible to have one colour on one side and a different colour on the reverse. It may be a shabby example with sparse artistic merit but it does show us that there is no colour bleed from one side to the other other than my messy experimental workmanship.

dscf3549-glassline-paper-diyThe picture you now see offers a few examples that show we’re not limited to what Glassline have in their Glassline Paper product range. The grey-looking rectangle will fire to double-sided black. The narrow strip at the top has different colours on each side. The two examples on the right are single-sided and have two colours. The remaining example at the lower left is a single colour of brushed stippling.

And finally, do remember that when the thinfire paper has been fired, the Bullseye logo and associated markings will disappear.

I think you get the idea and hope these example inspire you to do your own experiments.

Thinking About Economics

It is worth considering the relative costs of buying ready-made Glassline Paper against making our own. What follows is a quick analysis that in turn will lead to some simple conclusions. If you’ve had your fill of mathematics then just skim read this section!

To begin with we need to know how much it costs to buy ready-made Glassline Paper. For those of you in the USA I offer you the Suede Glassline 5″x5″ Stone Paper kit as an example. For this product three sheets of 5 x 5inch costs $15.45. This equates to about $0.0319 per square cm.

By contrast, in the UK we might expect to pay £8.91 or thereabouts for a mix of 15 sheets of 6.5 x 6.5cm at Warm Glass UK. This is a similar quantity and equates to about £0.01406 per square cm.

We now need to compare this with the costs to make your own version of Glassline Paper.

Bullseye Thinfire paper costs vary depending on how much you buy and where you buy it. For the purposes of our calculations let’s take £19.47 for 10 sheets of 52x52cm quoted by Warm Glass UK. This turns out to be about £0.000720 per square cm. With modest bulk buying the cost of the Thinfire paper turns out to be a negligible cost when heading down the DIY route.

Glassline Pens cost around £7.25 or thereabouts from Warm Glass UK when bought in 2 ounce bottles. That’s about 56 grams for those of you who stopped using Avoirdupois units decades ago. Translating this mass into how much gets used per square centimetre is rather tricky as it depends on what we’re doing and how much water is in the mixture. A light wash of colour is going to use a lot less than a thick coating. All we know is that the colourant is costing us £0.1286 per gram used.

Let’s look at the problem in a different way instead. If we can limit our use of the Glassline colourant to less than £0.01334 per square centimetre we’re on a winning streak if we’re out to save money. We know this because we have calculated how much the finished Glassline Paper and raw Bullseye Thinfire papers cost per square centimetre.

But how much can we squirt out of a Glassline Pen before it costs us £0.01334? A quick calculation tells us it will be about 0.1037 grams per square centimetre. A tenth of a gram is a tiny amount, nothing more than a blob on the end of a skinny wooden coffee stirrer. However, even a tenth of a gram is enough to cover a couple of square centimetres of Bullseye thinfire paper with a heavy application and considerably more for a light coating.

But let’s not forget that we’re likely to find ourselves with mucky paintbrushes, palettes, airbrush equipment or whatever else we’ve been using as tools. Some of what was in our Glassline Pen will go down the drain as waste. Waste costs money too.

Practical Conclusions

If you have painterly skills then making your own versions of Glassline Papers is a viable proposition in many situations. Sometimes the cost to buy ready-made outweighs the time and effort needed to produce your own equivalent versions. Sometimes the uniqueness of what you make makes simple cost comparisons pointless. It’s a matter of judgement.

A generally applicable comment is to buy cheaply and minimise waste. This is common sense, but a failure to do this can negate your attempts to save money if that’s what you’re aiming for.

Heavy coatings of colourant laid on Bullseye Thinfire paper ought to be a financially viable alternative to buying ready-made Glassline papers but three factors should be borne in mind. If the thinfire paper is being purchased expensively in small quantities and if the results of the DIY activity result in a lot of waste colourant it is easily possible to make papers that are more expensive than could be purchased ready-made. Also realise that the time you take to make such papers adds to their cost.

In extreme contrast to heavy coatings, an airbrush can be used to disperse small quantities of watered-down colourant over a large area as speckles. This method ought to be the least costly because it uses the least quantity of colourant. Do remember that airbrushing speckles will only be financially viable if you already own an airbrush.

Related to speckled effects would be brushed effects, drawn effects or sponged effects, especially when watered-down colourants are being used. Again we should expect relatively low costs that are viable compared to ready-made papers.

Some of the Glassline papers will be harder to replicate and will use a lot of colourant. Examples of the crinkled, granite and sandstone papers where Glassline use two colours and/or the thinfire paper that has been “crumpled” and flattened-out before applying the colourants. Unless there is a compelling reason to make your own I reckon it’s not worth the trouble to make these at yourself, other than as experiments for the learning experience. Not only will it be a time-consuming task but the amount of colourant and waste colourant are likely to make it more expensive than ready-made papers.

A final conclusion is that we now realise that Glassline papers with overspill on their backs can be “finished off” to make them double-sided rather than “single-sided with mess on the back”. It may not matter to Glassline, but I try to consider how things look from the back of what I make.

In the final analysis, the most compelling case for producing your own papers is when you want to colour both sides of the thinfire paper and when you require colours or patterning that can not be obtained ready-made from Glassline.

Posted in Experiment, Glassline Paper, Glassline Pen, Inclusions, Money-saving ideas | Tagged , , , , , , , | Leave a comment

Secrets of the Microwave Kiln

I’ve just bought my third Hot Pot Maxi microwave kiln. But, why buy yet another “toy” kiln when I already have a “proper” glass kiln of a distinctly robust and modern design?

I hope to answer that question by talking about the distinctive nature of firing glass in a microwave kiln, a little about the economics of using them, and a little about how they work and how they deteriorate.

I think I need to do all of this because I don’t see anyone else talking much about it.

Experiences With a Microwave Kiln

I still use a microwave kiln because I can melt a small arrangement of glass and have it back out and in my hands, fused and shiny, within about two hours. My “proper” kiln makes me wait a whole day (and night). So, speed and convenience is one reason.

The barely-controllable ferocious heating in a microwave kiln results in a greater risk of glass cracking at it heats up and the lack of processing temperature control means it’s not uncommon to find a mutant distorted blob of glass is the unexpected result of a firing. And of course the small firing chamber means we don’t get to make anything larger than a brooch or pendant. Sometimes this is not a problem.

The down-side of the almost uncontrollable heating, as I’ve just mentioned, is that the shape and form of the resulting glass masterpiece is rather unpredictable. This becomes a particular problem when the microwave kiln gets older and heats less evenly. I’ll be coming back to the “getting older” aspect of microwave kilns later as it seems to be a widely neglected topic!

Another characteristic of microwave kilns is the incredibly rapid cooling inside the microwave kiln. It has scant regard for “proper annealing”. You might think that this must lead to problems but in truth it very rarely does.

We are repeatedly told that it is important to properly anneal our work. From this we might suppose that the rapid cooling in a microwave kiln without “proper annealing” might cause us significant problems. In truth I find that breakages caused by poor annealing are very rare. If this is a surprise to you then consider the size of items being produced and realise there’s only so much stress and strain that can be built up and “stored” in such a small piece of glass. This is particularly the case for simple shapes like a blob of glass, a little decorated tile or a simple pendant – in other words, exactly the kinds of things that you’d use a microwave kiln for.

You can, of course, pop your microwave kiln masterpieces into a “proper” kiln to “properly anneal” them though we can take paranoia too far sometimes.

Another aspect of the rapid heating and cooling in a microwave kiln that I have not seen mentioned anywhere relates to devitrification. With a microwave kiln the processing time is so short that glass that is susceptible to devitrification rarely has time to devitrify. A practical consequence is that I am able to reliably produce recycle my otherwise unusable scraps of “ordinary” non-fusing glass into blobs with little risk of devitrification. You can see real examples in my Recycling Scraps of Stained Glass blog and you should bear in mind that every single glob you see in the picture is not fusing glass. For the lazy amongst you, and because it’s colourful, I’ll re-post the picture from that blog:

DSCF1857 Recycled Glass Globs

And here’s and interesting example that proves the opposite situation from my last blog. This little wonderous spiky blob of glass devitrified before it melted completely:

DSCF3010 Spiky Devit

The big surprise is that my “proper” kiln fails to produce shiny globs with “ordinary” non-fusing glass. Devitrification is always a problem. Processing time is important when dealing with glass that was not designed to be re-fired.

In other experiments, using a “proper” kiln, I find that most kinds of “ordinary” non-fusing glass can barely cope with slumping without devitrifying at least to some degree. Someday I’ll do a blog about this but I’ve not finished messing about yet!

Reasons to Use a Microwave Kiln

A consequence of the foregoing chatter is that I continue to use a microwave kiln in four very particular situations:

  1. I can quickly and cheaply perform a simple glass-related experiment in a microwave kiln. Firing-up a big kiln and wait a whole day to find out what happened can be too long to wait sometimes.
  2. Children visiting for a “smashing time” can arrive in the morning to make something small and simple in a microwave kiln then take it home that same afternoon. While they wait for the microwave kiln too cool down they can also make something bigger and more “special” that later will go into the big kiln. Immediacy is important for kids, as is the excitement of seeing seething red-hot glass when they “peek”.
  3. I can recycle scraps of non-fusing glass into blobs without devitrification problems and in turn it means I throw very little waste glass away.
  4. I can quickly make small quantities of frit balls (and other similar little things) when I run out of them which means I don’t have to suspend my project work for a long time. That they’re badly annealed doesn’t matter here because they will be fired again!

You may be surprised to learn that point (3) is what my microwave kiln gets used for most of the time. Let me explain…

No matter how hard we try to make use of smaller pieces of glass we end up with small scraps that are unusable. Where possible unusable scraps get melted into globs. It makes environmental sense through I doubt the time and effort to make them is commercially viable.

Some of the smaller globs (under 6 grams) I use in my own copper-foiled work or give away to other crafters when we meet at events. They might end up as a glass highlight in a wooden decoration for example.

Larger globs (typically 6-10 grams) are supposed to be sold though I tend to give away most of them. My rule is simple – kids who show an interest in my work can have one free but horrible kids have to pay for them. There has to be a reward for being “nice”.

Microwave Kilns Deteriorate

I’ve already mentioned that I’m now on my third Hot Pot Maxi microwave kiln. What happened to the other two?

As battered and bruised old-timers the old microwave kilns have been retired. They now live in landfill. The blunt truth is that they’re fragile, get damaged easily and really do get old and tired.

I should now explain how a microwave kiln works (in brief) and then pull-in information to explain how and why they deteriorate and get old.

The body of a microwave kiln is made of a light and brittle ceramic material. Considering how light and thin the ceramic material is, it performs remarkably well as a thermal insulator.

With a new microwave kiln we can expect the grey heating material to heat up reasonably evenly. The relatively small degree of uneven heating will be caused by subtle differences in the mixture of materials and their thickness. With time the degree of uneven heating gets worse for reasons that follow…

Repetitive heating and cooling causes repetitive expansion and contraction which will result in hairline cracks. The brittle nature of the ceramic material (and the inside coating) of a microwave kiln means it starts rather soon and gets progressively worse the more you use the microwave kiln.

Exactly where the hairline cracks appear depends on the unavoidable “defects” of manufacture and some basic physics. That the cracks always seem to run from top to bottom is purely down to the combination of geometry and coefficients of expansion – the inside gets hottest so wants to expand proportionately more than the outside. The reverse happens when cooling. This difference causes stresses and strains which result in hairline cracks appearing. So, don’t be unduly concerned by hairline cracks because they’re a natural consequence of the heating and cooling and the materials being used.

We now need to remember some high school physics. Do you remember that heat can be transferred by any combination of conduction, convection or radiation?

The hairline cracks will cause uneven heating because areas that heat up fastest can not conduct some of their heat to cooler areas because of the barrier caused by the cracks. So, any minor differences in one area heating up faster than another due to original manufacturing “defects” is made more pronounced when hairline cracks come into play. As the size of the firing chamber is so small we can assume there is no heat transfer by convection. There will however be some heat transfer by radiation because that’s what we’re using to heat up the glass in the firing chamber.

So, uneven heating becomes an unavoidable and noticeable problem once the microwave kiln starts to develop hairline cracks. This in turn adds to the unpredictability of what you can produce in a microwave kiln. A partial answer to this uneven heating is to pause the firing mid-way, have a peek, rotate the lid by half a turn, then continue to the firing. With practise and good timing this can almost negate the effects of uneven heating.

Glass slippage is another problem because. It is very easy to accidentally nudge the lid of the microwave kiln and cause the glass pieces inside to slip. A microwave oven platen that rotates badly (wobbling or shuddering) can also cause glass to slip. Heating too rapidly may cause glass to crack and move, so is another form of slipping. Any of these (and other) mishaps may result in hot glass “gluing” itself onto the base or the sides of the microwave kiln. You can also achieve the same effect by over-cooking the glass such that it becomes very fluid and “runs” to the side of the kiln to glue the top and base together.  Yes folks, I confess. I’ve experienced all these mishaps.

The trouble with glass fused onto the ceramic material is that you will find yourself gouging a big hole into the base or sides of the microwave kiln in your attempt to remove the glass. It is rarely possible to remove the glass without damaging the ceramic material, even if you have use kiln wash to protect the kiln base. Such mishaps tend to shorten the life of a microwave kiln, either because you find yourself with a kiln base that resembles the aftermath of World War I trench warfare, or sides where big chunks of the grey heating material are missing.

Using kiln wash and fibre paper can help deal with some of the problems some of the time but in my experience they will only reduce the rate of kiln destruction!

Another aspect of the deterioration relates to the heating ability of the dull grey gritty substance on the inner surface of the microwave kiln’s lid. It’s the heating element. The dull grey gritty substance is something I’ll talk about in more detail at the end of this blog so for the moment just accept that it is chosen for its ability to absorb microwave energy and re-emit that energy as heat. In other words, a microwave kiln works because of a peculiar characteristic of the grey material.

I am not sure why, but the effectiveness of the grey “heating” material seem to deteriorate over time, partly because of minor mechanical defects such as hairline cracks, but also because it seems to take longer and longer to heat up as the kiln is used more and more. This is something I noticed with my first microwave kiln but I hadn’t been keeping any records.

The fact it takes longer and longer for the microwave kiln to heat up with age implies there is some form of chemical deterioration in the “heating element” part of the microwave kiln. Anything that’s hot and in air tends to get oxidised as a matter of routine. This is perhaps most familiar to you if you’ve ever put some lovely salmon-pink shiny copper elements in your kiln-fired work and was disappointed to discover they came our red, purple or even black as heat and oxygen progressively turned the copper to copper oxide. This is what heat and oxygen routinely do to most things around us. This is what I suspect is happening to the “grey stuff” in the microwave kiln. But I suspect there are two other possibilties.

One of the alternative possibilities is that metals in coloured glass are “firing off” and reacting with the heating element. The other possibility is that the mixture of materials in the heating element react with each other causing chemical changes.

Whatever the cause, the effect is that the heating element becomes less susceptible to microwave energy so is not able to re-emit heat so effectively.

Firing History

My first microwave kiln told me that there was deterioration. So, for my second microwave kiln, I kept a record of each firing. Not much more than the date, what kind of task and how long it was “cooked” in the microwave. What you see in the graph below is the result of my nerdy record-keeping. Have a look at the graph then I’ll explain what it all means.

firing-times

The graph shows that my second microwave kiln didn’t quite make it to 300 firings before I felt it was time to throw it away. The exact number of times was 283.

You can also see from the graph that the jagged curve runs from the lower left (the first few firings) to the upper right (the end-of-life firings). Notice also that the curve is steeply upwards on the left and goes shallow on the right. This curve tells us that a new microwave kiln is much quicker than an old one and that the super-duper performance of a new microwave kiln doesn’t last long.

Notice that I’ve scaled the processing time so that 100% represents how quick the new kiln was. This means that when I threw it away it was taking almost twice as long to do exactly the same job – over 180% of the original firing times. Notice also that the graph shows us that the rate of deterioration slows down and seems to be levelling out at around 180%.

There are consequences for this “deterioration”. One is that it takes more time and energy with an older microwave kiln when compared to a new one. The other is that there’s no point in relying on detailed accurate firing records with a microwave kiln because its behaviour changes over time.

I’ll now reinforce that last paragraph in a different way. If you use a firing time from an old microwave kiln to guide to what you should do with a new microwave kiln you will likely “double blast” your glass. It will be “double processed” and you may end up producing an very runny pool of molten glass. And runny molten glass flows rather well if a surface is not exactly level. This is how I managed to “glue” the inside of the lid of a microwave kiln onto its base using molten glass. Don’t be as stupid as I can be. Consider yourself warned!

Now that we have some evidence about how microwave kilns deteriorate, and why, lets look at the economics of using a microwave kiln.

Microwave Kiln Running Costs

There are different brands of microwave kiln and some brands come in different sizes. The kind I’m using has a firing chamber that is about 10cm in diameter and cost about 50 GBP. Knowing that your 50 pound investment will deteriorate and may be ready for landfill after about 250-300 firings is something to think about. So is the ever increasing cost of the electricity, the kiln wash, fibre paper, currency exchange rates etc.

So, how much does it really cost to fire-up a microwave kiln? Lets find out…

I’ve already mentioned 50 pounds Sterling (notice it’s “Pounds Sterling”, not “English Pounds”) as the purchase price of my new microwave kiln and that I got 283 firings out of my second microwave kiln. So, that’s about 17.6 pence per firing due to the kiln cost.

But electricity also costs money. I am using an old 650W microwave oven. The 650W measure is the microwave output, not the electricity consumed. From the technical information at the back of the microwave’s manual I see it consumes 1.1kW per hour. So that’s about 60% efficient. My electricity costs around 16 pence per kWh and I’ve factored-in a proportion of the standing charge. We end up with just a few pence of electricity per firing which I can now plot on a graph.

firing-cost

I see that the cost starts somewhere between 3 or 4 pence, quickly rises to nearly 5 pence, then slowly drifts upwards to a little over 6 pence per firing. If you compare this graph with the previous one you’ll see exactly the same shape but a different Y-axis scale. This is because we’re doing nothing more complicated by converting a Y-axis in units of time into units of pence by multiplying by a constant value. For full marks in a mathematics exam I should have perhaps chosen a Y-axis starting at 3p rather than zero to make better use of the space.

Other Running Costs

There are other running costs that were not included in the previous graph. We tend to use some kiln wash to protect the base of the microwave kiln. A tiny fraction of a penny per firing for kiln wash is negligible compared to the cost of your time and the other costs associated with running a microwave kiln.

You, like me, might also use Bullseye’s thinfire paper between the glass and the kiln surface. It’s expensive and it can’t usually be used more than once. But how expensive is it?

If you’re lazy you’ll buy ready-cut 10cm squares at around 11 pence per firing, such as from here at Glass Studio Supplies in the UK but if you compare the price for buying 100 big sheets, such as from here from Warm Glass in the UK, you find you could instead be paying around 6 pence for the same amount of thinfire paper. All it takes is the will to buy in bulk, a pair of scissors and a few minutes of your time.

And finally, we need to remember to allocate a portion of the cost of buying the microwave kiln to each firing as well as the electricity cost, both of which were calculated in the previous section.

Overall Running Costs

My second microwave kiln tells me to expect a lifetime of about 250-300 firings, or maybe more if I treat the microwave kiln with more respect and care. As most of my use of a microwave kiln is to produce circular blobs of glass, we’re talking “full-fuse-plus”. We might therefore reasonably expect a longer life for the kiln with profile fused work.

Record-keeping may be boring and nerdy but it clearly has its uses. I now know the lifespan for my second microwave kiln and how it has behaved from new until the time I threw it away. Combining all the information at current (2016) UK prices tells me that the total per firing will be somewhere in the region of 25 to 35 pence, depending on how old the microwave kiln is, the kind of work being done, and whether or not I am prepared to buy raw materials in bulk.

You might like to think about how costly it is to fire-up your “big kiln”. The same ideas and methods apply, but the numbers will be bigger.

How Microwave Kilns Work

If you’ve got this far and have an urge to find out more about how microwave kilns work, and would also like to know how you can make your own, you’re in luck. I’ve gathered together a few links below which I’ll pad out with some commentary.

When you hunt around the Internet you’ll maybe find some misleading information about “the grey stuff” in a microwave kiln. The grey material is not granite, nor is it graphite. It is a mixture of silicon carbide and sodium silicate. Notice I say silicon and not silicone. Silicon is a shiny silvery metal. Silicone is a kind of plastic used for waterproofing products, breast implants and more besides. Silicon and silicone are not the same things.

You will be familiar with silicon carbide as an abrasive if you’ve ever tumbled rocks and minerals. You will also be familiar with sodium silicate though it’s unlikely that you realise it. Both are inexpensive chemicals that you can buy on eBay and I’ll give you a couple of links later that tell you more about both of them.

Once upon a time I found a reference to both these materials when I was reading something about LVR Products’ Micro-Kiln EZ-5 and Micro-Kiln No 9. I made a note that in their parts list it said there was a ‘Repair Solution Set’ which consisted of Silicon carbide (solution A), Sodium silicate (solution B) and a Brush. I forgot to make a note of the URL and I can’t find with Google any more, so I’m sorry I can’t give you a link to this evidence. But not to worry. I have more sources of information that should reassure you I’m not talking out of my backside.

Silicon carbide is used as the heating element because it has the interesting property of absorbing microwaves and re-emitting the energy as heat. You can find out more about this grey “heating” chemical at Wikipedia’s entry for Silicon Carbide (especially in the Heating Elements section). You will also find silicon carbide mentioned in some of the links listed below.

To “glue” the silicon carbide to the microwave kiln lid requires a binding agent and although there are several possibilities, you will you find that the commercial repair kits seem to use sodium silicate. Find out more about this “binding” chemical at Wikipedia under Sodium Silicate (especially in the Refactory Use section).

Over at Paragon you will see repair instruction that mention a silicon carbide layer. Actually, this is a very useful little instruction manual for any microwave kiln user, not just the Paragon MagicFuse microwave kiln.

You can get a really good insight into how microwave kilns are made by watching a YouTube video called How to make a microwave kiln (Furnace) from scratch for £5. The audio is not good but it is worth the struggle. Not only will you see a microwave kiln being made but you discover silicon carbide is just one of many “susceptor” chemicals that can be used as a heating product and that there are different binders, not just sodium silicate. Also interesting in the narrative is an explanation of how the same heating method is used to cook microwave chips.

You can find out more information about microwave absorbers here though in a completely different context.

If this isn’t enough for you then there is an old technical reference about “self heating” ceramic crucibles for microwave melting of metals and nuclear waste glass  at the Office of Scientific and Technology Information in the USA which is not as irrelevant as you might initially suspect. Vitrification has for many years been considered as a “safe” method of disposal for nuclear waste materials.

For the fearless amongst you, I have found some rather technical references. I can promise you an especially dreary read with this patent. If it is too much for you, I suggest try the readable article here because they’re both about the same thing.

Are We Being Ripped-Off?

And finally, we should give some thought to whether microwave kilns are good value or not.  The same applies to repair kits that you might encounter.

For almost the cost of buying a replacement microwave kiln you can buy a microwave kiln repair kit. One example is here. I am always suspicious of spare parts and repair kits that cost almost as much as the original item.

If you have a look in eBay (or elsewhere) you’ll discover just how cheap silicon carbide and sodium silicate really are. This should make you wonder why there’s such a big difference between the price of these raw materials and the price of a commercial kit or a microwave kiln.

If you understand the instruction in the YouTube video I mentioned in the previous section you’ll begin to understand that 50 GBP is ten times the cost of making your own. Again, this should make you wonder why there’s such a big difference between the price of the raw materials and the price of a commercial microwave kiln.

Yes folks. Information is power. The power to exploit. And now you know their secrets they can’t exploit you so easily. But you can exploit what you know. You too can make a microwave kiln. You too can buy the materials you need to make your own repair kit.

If you enjoy making things and you don’t have a microwave kiln then making one is surely a candidate for the top of your “Things to Make” list.

Bye for now. Tomorrow I’m going to make some rainbows. How about you?

Posted in Devitrification, kiln schedule, Melting Glass, Microwave kiln, temperature curve | Tagged , , , , , , | 4 Comments

Traditional Leaded Light Construction

It’s not often that I construct a leaded light but having done so recently I thought I should share some notes with you. They may help you as a newcomer or give you some new ideas if it’s an activity you’re already familiar with.

I really cannot claim to be an expert so you might have different opinions and ideas and might even think I’m doing it all wrong. Use your own judgement and decide for yourself. Sharing the information is what’s important from my perspective.

Rather that write this blog as a tutorial, for which there are several to be found online and in books, I will break down my notes into short sections that broadly follow the construction steps but I will not concern myself with step-by-step instructions. Sorry if you find this results in a blog that is a little incoherent at times.

Two Schools

There are two schools of thought about what to do once a cartoon has been produced. The difference lies in the method by which a cartoon is translated into a set of glass pieces ready to assemble.

Incidentally, I use the word “cartoon” for a drawing of an intended design. You might be more familiar with “pattern”. I think there’s a subtle difference that makes “cartoon” more appropriate but we can beg to differ on this little matter.

The first school of thought is that you must make a copy of your cartoon and use scissors on the copy to make little templates that represent each of the pieces of glass. I find this time consuming and fiddly so only use this method when I am using opalescent glass or dark colours that I cannot see though.

The second school of thought is to use the cartoon to directly score the glass directly over the original cartoon. This is a quicker method, lazy some might say, because it requires no copy to be made and there is no scissor work. This is what I tend to do if I am using glass that I can see through. I also prefer this method because and there are no fiddly bits of paper getting in the way of glass cutter wheel and no little pieces of paper to lose. One might suppose that parallax error might make this method slightly less accurate because of the distance between the cutting wheel and the cartoon lines but for leaded light work this does not tend to be a problem.

As already mentioned in passing, I still sometimes have to use the first method when working with a dark cathedral or opalescent glass. In this situation I mark-out a copy of the pattern for individual glass pieces using tracing paper, cut-out the tracing paper and use this as the template. I then use a waterproof marker pen, or a white wax pencil, around the edge of the template to mark-out the perimeter onto the glass. I don’t stick the paper onto the glass and attempt to score around it as I find the outcome is worse score lines.

Whichever method you use, it can be a good idea to number the pieces of glass to match the number you’ve added to the cartoon (and maybe template pieces) so that you don’t forget where they go and indeed which way up the pieces of glass should be used. This is particularly important when the design is complicated and has many pieces of glass that are similar but not exactly the same.

DSCF3325 CartoonSomething extra that I do with leaded light cartoons is to pencil-in lines that represent the boundaries between the glass and leads. Whilst doing this I also consider how the pieces of leading will affect visual appeal, construction strength, how it will be assembled and so forth. So, in addition to marking-out where there will be leads I also mark how those leads should be cut and jointed as a reminder for later. Look at the picture for a better understanding of what I mean.

The thick black lines on the cartoon will be explained in the next section.

Can you see I stopped bothering to mark out the cames and joints in the lower part of the panel because it was the “easy and obvious” part? I find that marking-out the cames and joints is more important for the complicated or intricate areas than elsewhere so I sometimes allow myself to be lazy in the less critical parts of the design.

If you leave these assembly and jointing considerations until the assembly phase of the construction and try to do it “on the fly”, your mind and your eyes will tend focus on the immediate task at hand – which is to say the current piece of glass and lead came. This means you will tend to neglect the “bigger picture” and often forget any thoughts you had about what to cut, where to joint and so forth.

Another dividend is then repaid when assembling the panel because you instantly see whether or not each piece of the lead work is being placed exactly in the correct position and is the expected shape. This in turn means construction problems are caught early and can be addressed immediately. You don’t have to wait until the panel has been fully assembled to realise that lots of subtle little errors have produced a wonky distorted panel that’s not quite the size it was meant to be.

Cutting the pieces of glass to the “right size” is important and the “right size” depends on the construction method and materials being used.

If you simply score along the cartoon pattern lines your will end up with glass pieces that are too large because no allowance has been made for the thickness of the lead between pieces of glass in a leaded light. A different allowance must also be made for the a double-thickness of copper foil (and a little solder) when using the copper-foiled method. So, the “right size” is a little smaller than the size on your nicely drawn cartoon drawing.

Commercially available pattern shears are available that will automatically cut on each side of the cartoon’s lines to help you with this task but I do not use them. One kind of shears is for copper-foiled work and the other is for leaded lights. The only difference between them is the amount of size-trimming that they perform. But there is a simpler method that is not only cheaper but is, at least in my opinion, more effective…

Look back at the previous picture and notice the thick black lines. Then read on…

Mark out all the glass boundary lines in your cartoon design with a felt tipped marker pen that produces lines about 2mm thick if it is going to be a leaded light. If you intend to use the copper-foiling method then a finer marker pen that produces lines no more than 1mm wide is appropriate.

You will then score along the edges of these marker pen lines, not the middles of them.

Thus, the thick marker-pen lines represent the channels inside your lead cames. Because 2mm is slightly more than the thickness of lead in the channel we can be sure the pieces of glass will not only fit but should rattle slightly.

The reason we should aim for slightly under-sizing the glass pieces is to ensure that the panel as a whole can be constructed exactly as the cartoon design intended, which is to say the final product will not contain distortions and can be made to exactly the correct dimensions. Although there will be some rattling of glass pieces around the constructed panel it will be entirely resolved by the waterproofing and strengthening stage of construction. But, there is a difference between being “a little too small” and “too small” and it depends on the width of the lead cames you are using. Wide leaves (flanges) of chunky cames means you’re allowed more latitude. Narrower cames demand more careful cutting!

And by the way, if you have the habit of using waterproof marker pens to mark-out the glass cutting lines then a smear of something like petroleum jelly (eg Vaseline) will help to stop the lines washing off when subsequently grinding. An alternative is wax pencils. A lazy third alternative is to place a sheet of clear acetate over the cartoon to protect it from water, then repetitively grind and check the piece of glass against the cartoon.

Obtaining and Storing Lead Cames

Lead cames are produced in straight lengths and that’s how you should try to obtain them. Avoid buying lead cames that have been coiled-up because it requires more effort to straighten them and increases the chances of physical damage. If this means you need to visit a stained glass supplies shop one per year rather than have it posted to you in coils then do so.

Once bought, give some thought to transporting and storing your lead cames straight and flat. Some possibilities are a long sturdy cardboard postal tube, a piece of plastic drainpipe or even a piece of plastic guttering. You glass supplier receives the lead cames in crates – maybe they are kindly folk and have one spare that you can have.

If you live in a damp environment, or your work area gets damp, try not to buy more lead came than you need as it will deteriorate through oxidation and become harder to solder. If you live and work in a nice dry environment then this is less of a problem so buying in greater bulk is more viable.

I have in the past been “donated” really old lead cames that had lain unused for many years. They had almost turned to black and were an absolute swine to solder and it was (in practical terms) impossible to “brighten” the leads where I intended to solder. So, if someone approaches you with a fist full of twisty mangled ancient lead cames, politely decline the offer even if they are free!

I should perhaps briefly describe some common forms of lead came, particularly for novice readers. What you choose comes down to artistic necessity, suitability and experience.

H-section cames are what you will mostly use so I will talk mostly about them. You will notice they have 5mm wide channels into which the glass pieces fit. The overhanging leaves (flanges) will keep the glass in place even before you’re waterproofed and strengthened your masterpiece.

But why not a 3mm channel for the glass we tend to use? The answer is easy. Think about the effect of surface patterns and the thickness variation of hand-blow glass. The extra 2mm is needed to accommodate such situations!

Another aspect of H-section cames is that the leaves “overhang” the glass by differing amounts. In this regard it is like choosing between thin or fat copper foil – part of the choice relates to the visual effect but there are also underlying practical consequences. A consequence of choosing H-section cames with wide leaves is that there is more latitude for error in the glass cutting and a stronger layout at the expense of a “chunky” appearance to the finished piece. Finer cames demand more accurate glass cutting just as using skinny copper foil only looks good if you cut the glass accurately.

H-section cames are available with “leaves” that are may have flat or curved outer surfaces, or both. In practise it doesn’t matter whether the leaves are flat or curved, and you will not really notice the difference except in one situation – accidentally mix them up in the same piece and it looks shabby with both flat and curved surfaces on the same side. I’ve accidentally done this in the past so trust me!

There is no reason why you cannot mix-and-match different types of H-section came in the same piece. For example, if your design contains a nice traditional stylised flower (not unusual!) you might choose a “fatter” came below to represent a stem for that flower.

U-section came and C-section came need special attention because their names are often confused. U-section came isn’t just C-section came turned on its side! They have different cross-sections but more to the point, they have very different purposes.

C-section came might have curved or squared-off outer profiles when viewed in cross-section and tend to be used to form a framing edge for a panel or inside a wooden frame (eg a cabinet door). Consequently they are often used for a standalone piece such as a suncatcher and sometimes have a narrow channel that is around 3mm rather than 5mm so be careful before your buy such cames. Incidentally, I hate the term “suncatcher” because they don’t catch the sun and they’re not necessarily hung in a window and it explains why I tend to use the word “panel” instead. But again we can agree to differ!

C Section Came UseU-section came is interesting. When you find some to look at, notice the heavy-duty curved outer profile in cross-section. The reason for such a sturdy curved profile is because U-section intended to be used as the upper edge of a large panel section that will have another panel section resting on top. To understand what I mean, think of a massive stained glass window in a church which has, by necessity been constructed in sections. Now look at my rubbish little diagram to understand how the H-came (in red) and C-came below (in blue) are being used. Over time the H-section presses down under the weight of the upper panel and the H-section’s leaves will splay and form a nice neat seal over the C-section curve below. Rainwater will remain outside and not be drawn into the panel. A simple solution to making a massive glass window panels waterproof wherever they meet. Our ancestors were not so primitive as we sometimes assume!

And finally, remember there are other forms of lead came for special situations. Some cames are for forming a right-angle joint. There are others designed to be the perimeter of a piece that makes it easier to mount into a frame. Visit your stained glass shop or look at a web site and ask what they are intended for. Nice people like to share their knowledge and experience.

Stretching Lead Came

Lead came needs to be stretched a little before use, not only to remove kinks but also to make the structural properties of the lead change. Somehow a stretched came seems to be a little stronger.

Stretching ought to be done only once per came, so to avoid confusion don’t stretch a came until you need it and store leftovers in a different place from un-stretched cames.

Two people holding each end of a length of lead came with pliers (or a similar tool) can perform the stretching. If there is nobody to help you then a lead vice will be needed and the vice must be screwed to a table top or clamped into a sturdy vice. Don’t attach the lead vice to your best table and don’t trap one end of the lead came into a door frame – these are both effective ways to damage woodwork!

How far to stretch the cames is a matter of judgement. What you are aiming for is the removal of kinks plus just a little more. Do not pull too hard or stretch too far as the lead will start to lose its strength and become softer. Worse still is if you pull too hard and the lead breaks (usually at the pliers) because you will find yourself flying backwards uncontrollably!

Although kinks can be removed from a lead came by stretching, nicks and most crush-damage can not. A problem with lead is that it is very soft and therefore very prone to damage especially on the leaves. At best you might be able to use a lead knife blade or an All Nova tool to “flatten out” some of the damaged areas but, of course, you will be cutting up the cames in various lengths so you can plan to cut pieces between the points of damage, or if you’re sneaky you can ensure damaged areas are soldered over at joints. Constructing a panel from damaged leads, visible for all to see, reflects badly on your commitment to excellence so don’t do it. Hiding little areas of damage under soldered joints is another matter entirely!

From all this you’ll understand why it’s not a good idea to buy coiled-up lead cames and why it’s sensible to transport and store them tidy and flat. I’ve previously suggested cardboard tubes, drainpipes and gutters as suitable storage containers.

If you don’t have space to store your cames in full-lengths then you might try cutting them in half but this will limit the maximum size of panel that you can make. Another reason to cut cames into half lengths is when you’re not a strong athletic person or you’re on your own – it’s easier to pull a shorter length of lead came single-handedly.

Use an All Nova Tool

The All Nova tool is inexpensive and replicates the functions of traditional tools such as the lathekin, fid, oyster tool and others besides for burnishing, flattening and spreading came. Unusually for “multi-function” tools, which tend to do many things badly, this one is well-designed and does all the tasks asked of it properly. I think it’s an essential tool for anyone who does copper-foiling or leaded light work. Not really useful for fused glass work though.

I’ve never seen any “formal” instructions on what the various parts of an AllNova tool are designed for so here’s my take on what I’ve read and discovered for myself and I also attach a picture that also includes a few horseshoe nails and a few scraps of lead came (the purpose for which will become apparent later).

DSCF3326 AllNova ToolThe outside curve of the flat face at the flat end of the AllNova tool can be used for burnishing copper foiled work or to completely close the lead came channel gap around the peripheral edge of a leaded light.

The very end of the flat end of the All Nova tool can pushed into the channel of a lead came and gentle “pulled along” the channel to open-out a kink in the leaves of a lead came, or the flat face can be used on the outside of the lead came to close-up a kink in the leaves of a lead came. Although this flat end of the tool is useful for dealing with kinks and opening-up the channels, see below for how the heel at the “pointy end” can also be used to widen the channel down a full-length of a lead came in one simple action.

Another use for the end of the flat side of the tool, when inserted into the heart of a lead came channel, is to help push and shape the lead came around the profile of an adjacent piece of glass. This avoids the kinds of damage that your hands or some other tool might do when pushing against the structurally weak leaves of the cames.

And yet another use for the flat end is to gently open up the “crushing damage” that can and often does occur when cutting a lead came. Insert the flat end into the channel just behind the damage and pull through to the end of the came. The little crushed area at the end will be pushed back into shape. I sometimes also use of the flat-side of a lead knife to “finish off” the damage repair.

An All Nova tool can be used to widen the channel of a lead came if glass is too thick to be inserted into the channel easily, or if the channel is slightly closed. The heel area at the “pointy end” is a splaying tool. Hold the came end that’s nearest to you and put the ‘heel’ of the AllNova tool into the lead came channel nearest to you. Then gently push down the heel into the channel and push away from you. The amount of pressure downwards into the channel will affect how much you splay the leaves of the came so take care. Ideally, practise first on a pieces of scrap came to get the technique right. You will see the channel widen by an amount determined by the downward pressure being applied. If the channel is still not wide enough for your glass then you can try to pull back with the ‘toe’ of the All Nova Tool (remembering to now hold the came at the far end!). To be honest, I’ve never needed to use the toe-end of the tool as the heel seems to do enough of a widening job for my purposes.

A traditional oyster tool (long thin U-shaped blade with a handle) is another possibility for widening the channel of a lead came. There’s not much point in owning one if you already have an AllNova tool.

If you’ve used the heel to widen a came and it’s now too wide then the flat end of the AllNova tool can be used to reverse the over-enthusiasm. Press the flat side down and slide gently along the came to close-up the gap. A sort of gentle burnishing action you might say.

The pointed end can be used as a “picking tool”, for which the most obvious task is to remove excess cement after waterproofing a leaded light. Despite this suggestion, I tend to use matchsticks because they can be then thrown away. The pointed end could also be used for back-scratching and nose-picking. Well, that’s what I tell kids. Some believe me.

And finally, what’s the little hole for? To be honest I have no idea.

Preparing for Construction

Place your paper cartoon design onto a wooden base and firmly fix a batten along of the main (longest) edge of the design so that the design cannot move and you have an accurate straight edge to work from. Of course, this assumes you have at least one straight edge in the cartoon design.

Ideally I would add another batten at 90 degrees (or whatever angle is required) to form the second edge of the panel to ensure at least two side can be constructed with absolute accuracy. This also gives you a firm and well-defined corner out of which you assemble the panel. Get the angle wrong and the resulting panel will also be wrong!

I tend to leave a little gap between these two battens so that a lead came can “poke out” of the corner if necessary.

Masking tape is not very reliable to hold a cartoon design firmly, nor will it ensure that two sides of the design are accurately placed, but it is better than nothing.

Cutting Lead Came

There are different kinds of commercially available lead knife that are commonly used. The traditional ‘Don Carlos’ lead knife seems to be more expensive and in my experience works no better than a more modern lead knife.

Modern lead knives have a curved blade on one end (with a pointed end on one side) and metal cap at the other end of the handle. The metal cap is intended to be used as a hammer and is useful for driving horseshoe/glazing nails into the base board. It is a boon for lazy people because it means you don’t have to repeatedly swap between a lead knife and a hammer. Take care not to cut or stab yourself with the lead knife blade when hammering the horseshoe/glazing nails – enthusiastic hammering is a bad idea with a blade not far from your face!

An inexpensive alternative to the “proper” lead knives are putty knife or a cut-down wallpaper scraper which has been sharpened on a grinding stone (of the kind you would sharpen a chisel for example). Be sure the blade is strong and does not flex.

Later I have included a picture containing an improvised and a modern lead knife.

Just as the secret of a good steak is a sharp knife, so it is true for cutting leads. A blunt lead knife is harder to use than a sharp blade so sharpen the blade regularly. I use my kitchen knife sharpener for this purpose and it seems to work well enough.

There is something of an art to the act of cutting a lead. To begin with, place your H-section lead with leaves top and bottom and the channels to the side. Then, with the lead knife correctly placed above, use a gentle side-to-side rocking motion whilst pressing downwards. The wiggly rocking motion helps to work through the considerable amount of lead in the top leaves of the came. When you’re about to get through the top leaves, reduce your downward pressure because relatively little is then needed to push down through the channel part. And finally, increase the downward pressure to push through the lower leave of the came. If you can keep your knife vertical (except for the initial “wobbling” action) throughout this process you will get a nice exact 90 degree vertical cut. A nice vertical cut ensures the lead work is equally precise on both sides.

Practise makes perfect but sometimes some trimming may be needed to get the piece of lead to fit exactly in the panel. Hold the lead came in the same way and pare away at the end of the came until the exact length and angle is achieved. If necessary, flip it over and repeat from the other side. Wipe away the little pieces of scrap because they can damage a came if you subsequently try to “work” on top of one of them.

Once cut and trimmed to size there may be some crushing damage to the ends of the leaves. In addition to using the flat end of an AllNova tool to “pull though” the end of the channel I also use the pointed end of the lead knife to deal with any residual damage to the corners of the came. Crushing damage becomes an unavoidable problem when cutting the cames at shallow joint angles.

Remember that it is easier to cut the stretched came into smaller pieces to work with than a full length but it will mean a little more waste. Shorter lengths of came are also less likely to get twisted or damaged when they accidentally knock into other things nearby.

Use of a mitred or butted joint corners are equally acceptable. The choice depends on circumstances and generally butted joints are quicker and easier. Remember that the joint will be soldered so how you form the joint will not be visible. All that remains visible is the quality of your soldering!

Assembly

Glass cutting errors are not so critical for leaded lights when compared with copper foiling.  Actually we should be aiming for just a hint of “rattle” in an assembled leaded light because it tells you there are no “pressure points” that might cause stress fractures later.

Ideally you should strive for a situation in which you rarely need to use a glass grinder to finish off pieces of glass for leaded lights. Pause for a moment to think about the glass workers of times past when electric glass grinders were not available. Getting it right first time was important because all you had was grozing tool with which to “nibble” the glass and a scythe stone. So, let the “leaves” (flanges) of the lead came be your friend as they hide a multitude of sins, such as slightly mis-shaped pieces.

Assemble from the longest side of your piece first. It is usual to start the assembly in a corner that will at the base, working piece by piece away from the corner and up the side and across. Pieces of came will need to be cut enclose each successive piece of glass that is to be added.

Although it’s a rather vacuous statement, remember to pause from time to time as you assemble the piece to review progress and plan what needs to be done next. For example, sometimes you may find that you need to build a whole “sub-assembly” and add it as a whole rather than add pieces one part at a time. Remember that you are aiming to make the pieces fit accurately over the cartoon design as well as constructing a strong panel that will look good when soldered. This is not a trivial matter so that’s why I try to plan and record my cutting and jointing intentions directly onto the cartoon in the design stage.

To a significant degree your cartoon design ought to address many of the visual appeal and strength issues but there remains the matter of how you cut and connect those pieces of lead came. For example, running single continuous lengths along the outside of each edge of the whole piece is good for the strength of the panel. But what about a circle within the design – are you going to have a single piece of lead coiled all the way around? Where will you “make the join”? Try to think before cutting and fitting the leads. Better still, do it in the design stage!

To stop the assembly from slipping and falling apart you will find it useful to strategically hammer horseshoe/glazing nails around the edge of the part-constructed panel wherever they are needed to stabilise the panel. A dozen of these horseshoe nails is adequate for a modest sized panel.

Before you start hammering those nails into your baseboard and against the leads I remind you that horseshoe nails are made from harder metal than lead and can therefore damage the leads. I therefore recommend you place a piece of scrap came between the cames of your panel and the horseshoe nails as a softer protective spacer.

DSCF3281 LeadedAt this point I think I need to relieve your boredom with a picture. So, to illustrate what I have been talking about, look at the picture of the assembled panel. Notice how the circular area containing the rosebud has been pre-assembled before insertion. Notice also the little mistake on the right-hand leaf where I’ve inserted a little fillet of lead to “fill the gap”. I’ll talk more about this “bodging” when I chatter about soldering. Notice also the use of horseshoe nails with little scraps of lead to hold the assembly firmly in place. And finally, you might want to compare how I cut the leads with how I planned to do it against the cartooned design.

The outer perimeter of the panel does not need to be cut to exactly the right size to begin with but will need trimming when you have finished. This is why I mentioned that I often leave a little “gap” between the battens earlier on in my chatter.

But you may be wondering, especially as a novice, how to remove at least some of the guesswork from cutting the pieces of lead came accurately. Am I right?

Well, it depends on the situation as to how to proceed, but one extra useful hint is that a scrap of came can be used to “represent” what has not yet been fitted. It’s easier to show you than write it down but I’ll try…

Imagine you have a single piece of glass in your hand and that it’s a quarter of a circle. You want to cut the curved piece of lead but realise that the two straight sides of the quarter circle will also have leading. So, either the curved piece of lead needs to be slightly shorter than the length of the curved edge or the straight pieces need to be slightly shorter than the straight sides. Aaargh! This is partly why I think about the cutting plan at the design stage.

Let us assume the straight sides of the quarter circle will have full-length pieces of lead came and that the curve must fit in the remaining space. We therefore want the curved piece to be slightly shorter than the length of the curve of the glass piece. But how much shorter?

To remove guess work from cutting this curved came piece accurately,  first apply your piece of came to the curve and push it into shape along the curve. You could use the flat end of an AllNova tool to help you do this without damaging the lead came. Allow this length of came to overlap the ends of the curve at each end. We know we need to cut “something” off each end so need to figure out where exactly to cut the ends in order for them to both butt-up accurately onto cames running along the adjacent straight edges.

With the overlapping curved came still in place, lay short lengths of scrap came just next to the overlapping ends of the curves on each of the adjacent straight sides. These two scraps shows you where the real straight cames will fit. So, lightly mark the curved piece of came at each end with your lead knife with lines that extend the inside edges of the two scraps.

With the curved came marked, remove it, put it on a nice clean work surface, then cut through the came at the required angles at each end. The quarter circle of glass and the curved came are now ready to be added to the panel. If necessary hold them in place with a horseshoe nail and protective lead scrap.

DSCF3329 CuttingThe picture you now see is an illustration of what I’ve just been talking about and also includes of a lead knife made from a cheap wall scraper and a “proper” modern lead knife. If you click on the picture it will display in greater detail in another window.

Incidentally, I’ve deliberately used old lead cames for this picture so that you can see what happens after several years of storage in a relatively dry environment. Notice they are looking distinctly grey.

The upper-right area of the glass piece illustrates how a scrap piece of lead can be used (across the top) to gauge and mark where to cut the long curved piece of lead (on the right). The lower-left area of the glass piece shows the next step, where the lead has been cut and you should immediately notice that the curved lead does not reach the end of the curve. Notice also that when you follow the straight piece of lead on the left, downwards along the inner edge, it leads you neatly past the end of the curved piece. This illustrates what you’re trying to achieve with each pieces of lead came in the assembly.

But what happens when you later find that you have an assembled panel ready for soldering and discover that one of the leads was 1mm or maybe 2mm too short? Such accidents do happen but don’t despair. By all means investigate to understand how the problem happened, and learn from the mistake, but don’t dismantle the panel to re-make that piece of lead came because there’s a sneaky trick you can use and it’s another use for little pieces of scrap H-section came…

Although this trick may seem to relate to soldering, I’ve put it here because really it’s more about dealing with an assembly problem caused by mis-cut leads.

To fill in a rather-too-big gap easily and invisibly, first cut a suitable short length of the H-came that will nicely fit into the gap above and below. Then, use your lead knife to chop out one side of the H so that you end up with a T and an I piece (or two stubby T pieces if you prefer). These two pieces can now fill the gaps on each side of the panel.

When you are ready for soldering, insert the T-shaped portion to bridge the gap and solder as normal. The solder flows over the insertion and your trickery then is hidden behind the solder joint.

Later, when soldering the back of the panel, use the remaining I shaped piece but be careful you don’t lose it in the meantime. No, actually it doesn’t matter if you lose it as you can easily make another!

Defects larger than 2mm can also be dealt with in the same way, provided they are shorter than the size of the soldered joint to be produced. But, if you’ve got a gap larger than about 3mm you should start to wonder how you’ve managed to cut a piece of lead so badly wrong and not notice it before!

This trick is not needed for tiny sub-millimetre joint defects because solder will happily bridge small gaps.

If you refer back to the picture-before-last, you’ll remember I filled a little gap with a fillet of lead at the end of a rose bud leaf. On this occasion the fault was only on one side of the panel so I could simply bridge the gap on one side. Again, this becomes an invisible mend because it will soon be covered with solder.

Soldering Lead Came

If you are a novice with leaded light construction you will discover that soldering a leaded light is not the same as soldering copper-foiled work. For this reason I recommend you do lots of practise joints until you can confidently and reliably solder lead cames.

What I describe works for me but to be brutally honest I ought to practise my leaded light soldering more often because is “a bit dodgy” sometimes. Ask around and watch other people soldering and they will reveal subtly different techniques. With time you will find a technique that works reliably for you.

The key to successful soldering is preparation. With copper-foiled work your “safety flux” removes oxidised copper and this helps the solder flow and bond nicely. The situation with lead cames is subtly different because a different flux is used and oxidation must be removed before the flux and solder are applied.

Some people may tell you to use a fine-grade wire wool to remove lead oxides (ie “make it shiny”) in preparation for soldering. I have tried this method and although it works I have two objections to it. One is that it produces a lot of dust from the wire wool breaking down into fine iron particles. The second is that the rubbing process produces a lot of lead dust, some of which will become airborne whilst rubbing and also when cleaning-up afterwards. Lead is nasty when it gets into your body so, for your own health, don’t make lead dust when there is an equally effective alternative method that doesn’t!

The alternative to using wire wool is to lightly roughen the area around an intended solder joint with the point of a lead knife or a horseshoe or glazing nail or, in truth, anything else that’s sharp, pointy and can be used to scrape the surface of a lead came. You only need to get the surface shiny around the exact area where you will be soldering. This is simple, it’s effective and it’s not going to harm your health.

Now that you have some lead prepared and ready to solder, there’s an extra step I suggest, if you have the patience…

Take a moment to pack a small piece of cardboard or folded paper between the glass and lead came in the area where the joint is to be soldered. This preserves the gap, protects the glass and perhaps more importantly, it eliminates solder bead drops which may ultimately cause a stress fracture in the distant future.

Next is the application of the soldering flux. For leaded lights the flux is tallow and the form commonly used looks like a candle minus a wick. The tallow should be rubbed around the surface of the area to be soldered.

The method of soldering is also different from copper-foiled work. First feed a little solder onto your soldering iron so that it holds a molten bead.

If you’ve read my chatter about choosing the right solder then you know you ought to be using a 40:60 solder rather than a 60:40 solder and should understand why. But I digress…

The aim is now to transfer the solder bead from the soldering iron to the joint without melting the lead around the joint. Much practise is needed to achieve consistently good results and the most important thing to understand is that a confident and quick technique is the key to success.

Slowly bring down the soldering iron tip (with the solder bead), but try to stop when the iron’s tip is a millimetre or so above the lead came. At this point the solder will “find” the lead and begin to spread out by itself. Oh for the joy of surface tension!

You can then deftly move the soldering iron around (still trying to hover) to help the solder flow around to where you want it do go. The aim is not to touch the underlying lead with the soldering iron because you don’t want to directly transfer heat from the soldering iron into the leads and cause them to heat up and melt more quickly. I suppose this technique could be likened to rolling a blob of sticky glue around – the objective is rolling, not squashing.

The reason you need to act quickly and deftly is that the lead cames and the solder melt at similar temperatures and it does not take long for the heat in the solder to conduct into the lead, heating it up to melting point. This also explains why we don’t want the leads being heated up more quickly by being in direct contact with the soldering iron. So, speed and accuracy is important. Starting the process with cold lead is also important.

In my experience “fiddling around” trying to “fix” a bad joint rarely achieved more than melting the underlying lead and make a crisis out of a disaster. If you really must “fix” the joint, leave it alone and do not attempt to fix the problem until the joint has become stone-cold. I repeat this warning in different words to stress this point: do not be tempted to “fiddle around” when the lead is still hot because it’s nearly ready to melt!

Let us assume you’ve dropped your blob of solder, hovered with the soldering iron and have and wiggled and rolled the solder around to the point where it has satisfactorily covered the whole area of the joint. You must immediately  pull away the soldering iron because you don’t want the leads to melt.

And finally, an opportunity to clean-up as you go. As soon as the soldering iron has been removed, count a “slow 5” to give the solder enough time to become solid but not long enough to allow the tallow flux to solidify. It is now safe to wipe the soldered joint with a paper towel or a clean rag. This will remove excess tallow and save you a lot of difficult cleaning work later.

If you forget to wipe away after your “slow 5” then don’t worry. Bring your soldering iron reasonably close to the joint for just long enough to re-melt the tallow then remove the soldering iron and wipe away. Your objective is to gently melt the tallow and not to re-melt the solder!

Remember to remove your little piece of cardboard (or paper).

Waterproofing and Strengthening

In this section please notice that I do not use the word “putty” because it is the wrong word and the wrong product to be using when we concern ourselves with the waterproofing and strengthening our freshly soldered leaded panels.

Leaded light cement smells a little like ordinary glazing putty but looks different. Leaded light cement is usually dark coloured and always has a sloppier consistency. Both smell of linseed oil but leaded light cement smells more of turpentine (or substitutes). Another difference is that putty stays soft for many months, if not years, whereas the cement dries and sets within days. So, dear reader, there really is a difference between putty and leaded light cement.

If you’re not doing much leaded light work then remember that the leaded light cement will slowly “settle out” in the tin over the course of a year or two into a hard lump of solids underneath an oily top layer. Despite this, I have found that even after a few years of settling it can be “revived” and made usable again, but it is time-consuming process poking, mixing and squidging the solid and liquid portions back into something usable. This may be useful to remember if you’re short of funds but have plenty of spare time.

It is also a hint that you should not buy more than you need. Or, as an alternative, perhaps we should make our own, storing the dry and wet portions separately, then mixing only what’s needed when it’s needed. Oh dear. The formulation of leaded light cement. It’s another area I’ve yet to chatter about.

For the moment, I just warn you not to blindly follow the recipes that some people are publishing on the Internet. As you might expect, some are sensible but some of them are well-intentioned but reveal themselves to be ill-conceived on closer inspection. If some lengthy chatter about formulations for leaded light cement is important to you, please prompt me to do this sooner rather than later.

Right, back to topic of waterproofing and strengthening…

The general plan of attack in this stage of construction is to force the leaded light cement into gaps between the lead cames and the glass pieces. With the gaps filled we achieve a single solid structure. Over the course of a few days the leaded light cement hardens and therefore stabilises the panel and increases its strength. Once hardened the cement also forms a waterproof barrier.

The best warning I can give you is to not get too enthusiastic, trying to force too much into the gaps, because it’s only going to start oozing out of the other side of the panel. All you’re aiming to start with is to fill the gaps on the “upper” side of the panel. Once the whole process of waterproofing and strengthening is complete on one side, you can then flip the panel over and repeat on the “other” side. The elapsed time is days, not hours!

DSCF3286 WaterproofingHere is a picture to illustrate what I’m now talking about.

Waterproofing is a messy process so use plenty of newspaper under your work. Cheap throwaway toothbrushes and nail brushes are recommended for forcing the cement into the gaps. It is better to use throwaway items than buying and cleaning expensive brushes because the hardened cement renders the brushes useless. Can you see how messy the little nail brush is in the picture?

Another tip is that you can also use a piece of glass to ‘push’ the compound into gaps but I don’t tend to do this.

I should also mention that leaded light cement is fantastic at finding its way into the smallest cracks, crazes, and deep recesses of textured glass surfaces. Never forget that the cement can destroy the visual appeal of the most gorgeous piece of “unsmooth” glass with a patchwork of mucky marks that are impossible to remove. Protect the surface of any glass that has such surface imperfections by whatever means are available to you so that the leaded light cement can not find its way into these defects in the glass. An adhesive plastic film should work nicely, maybe even self-adhesive labels.

If you’re careful and don’t randomly slosh the cement everywhere then it’s going to be easier to “clean up” later. To this end, try to keep the cement close to the filled-gaps and do your best to not get the cement on the tops of the lead cames. Look at the picture to see how I try not to make too much of a mess but wasn’t entirely successful.

When you have cemented one side of the leaded panel it’s time to add whiting (see below).

Be aware that the volatile ‘drying agents’ in the cement are smelly so ventilation is suggested. It’s not that these vapours are toxic, it’s that their smell can be quite intense and last for days.

Once the whiting has been added, leave the panel overnight, clean-up that side of the panel then attend to the other side of the panel.

Whiting

Whiting is nothing more exciting than chalk powder and it needs to be sprinkled over areas where leaded light cement has been applied. An alternative to whiting is to use fine sawdust or fine wood shavings. Whatever you use, just remember that the aim is to “draw out” the oily part of leaded light cement.

Plaster of Paris and patching plaster have also been suggested as an alternative to whiting but I’d be wary of them because any hint of dampness may cause them to solidify on the surface of your glass, making the cleanup process harder. Let me know if you’ve tried these alternatives as I haven’t.

DSCF3288 WhitingHere’s a picture of a panel that has just had whiting added. It still looks nice and white but in a few hours it will start to look rather mucky. Notice that I’ve tried to put more whiting where there’s more leaded light cement and less where there’s (hopefully) only glass. Notice also that there’s whiting on top of the leads because there’s cementing “mess” to be dealt with on top of the lead work.

So, don’t be mean-minded with the whiting. Use as much as is needed. As a minimum at least try to get most of the whiting where there’s cement. In addition to drawing out the oily part of the cement, whiting also helps to clump together particles of excess cement and as such is really helpful in the “cleaning up” activities.

After a few hours the whiting starts to clump and look mucky. Now you may clear excess whiting off the glass surface carefully with a soft brush or a cloth but stay away from the leaded areas as they have not hardened sufficiently. Try and leave decent border (at least 2mm) around the leaded areas completely untouched. Carefully removing cementing compound from the tops of the lead cames is another task that can be started. Adding more whiting or shuffling “unused” whiting to where it’s still needed can also be done. So, at this stage our aim is to remove the worst of the mess without compromising the quality of the waterproofing or strengthening.

On the next day, no sooner, remove the 2mm borders carefully with a wooden stick, matchsticks, an All Nova tool or similar. This is where I mostly use used matchsticks. If you used enough whiting then the cement will have set sufficiently and this becomes quite an easy job. The clean-up process is all done when all the gaps between glass and lead are filled with cement and there are no stray lumps of cement on the lead cames or on the glass. Try not to under-cut the cames when cleaning away the excess cement because all it achieves is little water collection areas which are ideal micro-habitats that encourage algal growth especially in damper climates.

Once cleaned up, it will still take a few days for the remaining “drying agents” to evaporate out of the cement. As time passes the stink slowly subsides.

Finishing

Some people suggest that soldered joints should be darkened to match the lead work. Zebrite is a commercial product that can be used to blacken the lead and solder and is normally used to blacken stoves. Zebo is an equivalent product that is no longer made.

My experience is that these products don’t really work very well, except on stoves. They hardly take to solder and aren’t much better with fresh lead. So an alternative suggestion is to patinate (ie use patina) these areas first.

Better still, in my view, is to not bother with this step. Allow the lead and solder to do their darkening naturally.

Miscellany

Here are a few miscellaneous things that I couldn’t sensibly put anywhere else:

An alternative to using a grinding stone or grinder to remove a burr from glass is to run a piece of scrap glass down the edge of the cut edge. Quick and good enough for leaded light work. Another handy trick from the days before electric grinders.

Smooth side outside and textured inside is the old general rule for glazing leaded lights. This is simply because single-glazed windows get dirtier outside than inside. However, this becomes questionable when the panel is part of a double-glazed window pane or embedded into a triple-glazed window pane. For indoor decorative pieces it’s a matter of design because you might deliberately want people to touch and experience the different surface textures.

Installation

I do not tend to get involved with the installation of leaded lights so only have a couple of thoughts to pass on.

Using glazing putty to mount a leaded light panel into a window frame has been a standard practise for many years. It works and there are no nasty side-effects. Our ancestors knew what they were doing.

By contrast modern squirty plastic “caulk” type fixatives should be treated with caution as I have learned from personal experience. By “caulk” I am thinking of the kinds of product that you would use to seal the gaps around door frames or around a bath or sink. Take care with these products and check the labelling to see what happens when they “cure”. If the product produces a vinegar smell as it “cures” a consequence is that it will be prone to provoke a white powdery surface patina of lead acetate on nearby cames. Lead acetate is a far greater risk to your health than the lead of the cames.

Sometimes a leaded light panel is added as an indoor secondary panel against an existing window. I have seen double-sided sticky black butyl tape being used to attach the perimeter of a leaded panel to the perimeter of the pre-existing glazing. A typical location might be the window pane adjacent to a door.

Health & Safety

Last but not least is the dreaded Health and Safety section. It’s a must because we’re working with lead.

Working with lead cames to produce leaded lights raises a number of heath and safety issues and some of them I’ve already alluded to. I will now elaborate.

A guiding principle in health and safety is that the elimination of a hazard is always preferred to doing something that reduces the effects of a hazard which in turn is preferred to the use of protective equipment to “hide” from the hazard.

Lead cames and particles of lead are not, in themselves, toxic. It is the compounds of lead that are what we should be most worried about. It is biological and chemical actions that turn lead into compounds of lead that you need to be most wary of.

Already mentioned is lead acetate from “caulk” that may arise when mounting and installing a panel. Lead acetate is a compound of lead. It is a white powderly “bloom” and easily inhaled or injested if you don’t take care.

Another source of lead compounds is through the action of sweat on our fingers reacting with lead when we handle lead came or solder. So, although touching lead is not very much of a hazard to your health, the ingestion of lead compounds produced by the sweat on our fingers is bad news. The transfer route that leads to ingestion tends to be lead came to fingers to mouth. So, before you try eating, drinking and smoking, stop working with the lead and wash your hands first.

Ingestion of particulate lead and lead compounds can be caused by airborne particles and I’ve already explained why I do not use wire wool on lead cames. So, rather than waste time and money using cheap ineffective face masks, eliminate the creation of particular lead by not using wire wood to clean up lead cames.

Although not directly lead-related, remember horseshoe nails and modern lead cutters that double-up as a hammer. Here you need to be careful not to cause puncture wounds and cuts. Puncture wounds and cuts must be covered with sticking plasters when working with lead or other toxic chemicals. Cuts and wounds are a fast and efficient entry point into your body.

If you’re a bit paranoid, you might consider using some rubber or nitrile gloves to minimise your contact with lead. But don’t let these gloves lull yourself into a false sense of security – remember to wash your hands after you take them off.

Lead poisoning is one of the oldest occupational hazards due to lead mining over many centuries so a word about exposure limits is perhaps needed. The first point to make is that different nations have different legislation so I can only generalise.

Lead exposure limits are unlikely to be exceeded if you’re an occasional hobbyist. The trouble is that workers only occasional exposed to lead, and hobbyists, are not really in a position to measure lead exposure without outside help. If you are in the least worried, try talking to your medical doctor, or your employer’s occupational health service (if you have one).

The group at risk is full-time workers who spend a lot of their time working with lead and traditional lead-based solders.  If you are an employee in a company where working with lead is a significant part of your job then your employer ought to be monitoring your lead exposure routinely through periodic medical assessments. I say “ought” rather than “will” or “should” because theory and reality are rarely the same.

The world is full of experts in Health and Safety and unfortunately a lot of health and safety is about subjective opinion rather than reasoned facts. Unfortunately this leads to experts that are, to varying degrees, ill-informed, paranoid, obsessive, irrational, deliberately biased or downright dim-witted. Somewhere amongst the cacophony of mixed messages is a reasonable and rational basis on which to live our lives!

If you think I should do a blog on Health and Safety that identifies some of the hazards and risks of our activities and translates them into advice that is hopefully more balanced, rational and helpfully practical then please tell me that it’s something you want sooner rather than later.

A Topical Postscript

And finally, on the subject of Health and Safety, you may already be aware of what’s happing in Oregon in the USA.

I note with concern that “the authorities” in Oregon are behaving irrationally and badly towards glass producers Bullseye and Uroboros. You will find more information in the news releases section at the Bullseye web site. It makes interesting reading because it relates to to toxic metal emissions from furnaces.

The recent announcement by Spectrum that they are shutting down makes this even more worrisome for our chosen career or hobby.

This health and safety madness in Oregon reminds me of a quote attributed to Voltaire:

It is dangerous to be right when those in power are wrong.

Or perhaps this one from the painter John Constable:

We see nothing until we understand it.

Bye for now, dear reader. Thank you for visiting my blog.

 

 

 

Posted in Cartoon design, Flux, Glass Cutter, Lead cutter, leaded light, Leaded light cement, Putty, Solder, Soldering, tallow, Whiting | Tagged , , , , , , , , , , , , , , , | Leave a comment

Repairing a Broken Mould

Today’s chatter describes an attempt to repair a broken ceramic mould so that it can be brought back into useful service. The repair process takes time and patience but it might help you salvage a expensive broken clay mould.

If you’re from the USA then today’s extra learning is that when I write the English word “mould” you should pretend you saw “mold” and not confuse it with the Welsh town called Mold.

Some Background

Many years ago, when I had more teeth and my hair was pigmented, I was still naïve in all matters relating to fused glass. I bought a little teardrop mould that would fit into a recently purchased microwave kiln thinking that it would be fun to make some fused glass teardrops.

What I didn’t appreciate in those days was that a microwave kiln is a harsh beast with rapid heating and cooling that was going to be a problem for the mould. All I can say in my defence (or defense in you’re in the USA) is that there was no information sheet with the mould giving me a recommended kiln schedule which might have served as an implicit warning that trouble was ahead.

As I now know disaster was entirely predictable. The mould cracked into three pieces on my very first attempt to use it. So, for several years, the broken mould languished unloved but not forgotten in its box until I could figure out what to do with it.

Hindsight is a good teacher and lucky for me it was not an expensive mould.

The Underlying Idea

I know from previous experiments that a glass kiln may not be able to reach the high temperatures required to fire clay to completion, to the satisfaction of a potter, but can be processed in a glass kiln sufficiently to make a usable mould. The resulting moulds were not as strong as a “proper” ceramic mould but have shown themselves to be perfectly adequate for use with glass.

I therefore reasoned that it might be possible to use some clay slip (of thick double cream consistency) to “glue” the broken parts of the mould back to together then strengthen the joints by firing the repaired mould in my glass kiln. I was right.

The Outcome

DSCF3312 Mould RepairHere’s a picture of my repaired mould. It is a small Slumpy mould and has been repaired by the method I shall now describe for your. You can still just about see where there used to be cracks and you can see I still need to give it a final clean-up.

You’ll have to take my word that it’s now good enough to be brought back into use!

I hope you have equal success but if you have any extra good ideas to contribute then please let me know and I’ll update this blog with your new information.

The Repair Process in Outline

If you’re in a hurry or can’t cope with my copious chatter, here’s a summarised description of the repair process.

  • Clean mould, removing kiln wash and other contaminants
  • Wet mould then use thick clay slip as a glue
  • Clean away excess clay carefully
  • Allow mould to dry, using elastic bands (etc) to hold pieces in place
  • First firing to strengthen the repair joints
  • Second round of repairs with clay slip to address remaining defects
  • Second firing to make mould as-good-as-new

Read on if you’re still interested!

The Repair Process in Detail

The first step in the repair process is to thoroughly clean the mould, attempting to remove all traces of kiln wash, dust and grime. For this I used a single-sided razor, a kitchen scouring pad and copious amounts of water. In effect, this task is much like cleaning a kiln shelf before re-applying kiln wash. If you’ve unfortunately succeeded in dropping your mould before it was ever used then this step will not be needed.

If you’re previously prepared the mould with a boron nitride spray then you will not be able to completely remove the boron nitride. Do not despair. Try your best and stay hopeful as the coating should only be at the outside surface and not at the edges that will be “glued” with clay.

You will need some thick clay slip. I used exactly the same cheap clay for the repairs as I used for my previous mould-making experiments even though the clay was supposedly not suitable for use in a kiln! I mixed just enough water and some clay scraps to form a smooth gloop with a consistency of thick cream.

When you have a nice clean mould, pop it into a bowl of water for a few minutes. It is going to be easier (and the results will probably be a little stronger) if you “glue” the pieces of mould together when they are wet because dry pieces of mould will rapidly such the water out of the clay slip making it too stiff to accurately and neatly “glue” the pieces of together.

Next comes the gluing step. As you would with ordinary glue, apply a thin layer of your clay slip around all the edges that need joining. Gently push together all the broken pieces, trying your best to accurately place all the pieces together. Now is a convenient time to wipe away the worst of the excess clay slip that squeezes out. This step is made easier by having previously wetted the mould pieces!

Do not worry too much if a few little shards of mould have been lost, or the some of the pieces refuse to sit exactly where they ought to. This can all be resolved later!

With all your pieces of mould “glued” together it’s time to ensure that nothing moves until the mould has dried off. I used elastic bands but any other method that keeps everything stable can be used. Tight joints are what we are aiming for.

At this point a little gentle washing with a damp sponge (or fingers) can be used to remove some more of the excess clay. But be careful you don’t cause the clay mould pieces to fall apart or move. Do not worry if you can’t clear away all the excess. This can be done later.

Now leave the mould until it is completely dry. I think natural drying is the best choice because it allows clay minerals to “migrate” into all the tiny gaps which we are hoping will result in a stronger repair. Another reason is that using damp sponges and cloths in the next step are a little less prone to cause the repair to fall apart!

When the mould is dry, remove the elastic bands (or whatever you used) and inspect the mould. If any little holes need filling then now’s a convenient time to fill the holes. Leave the mould to dry-out again if you just did more repairs.

If there are any areas where there is an excess of clay then try to remove the mess with a damp sponge, dampened paper, or whatever else you think will work. You may find that dental picks, lollipop sticks and single-sided razors are also useful. Fingers are an amazingly useful tool as well! I remind you to be careful to not cause the ceramic mould pieces to move or fall apart. Unfired clay is not a strong glue and when you add water the clay “glue” suddenly gets even weaker. A strong hint for this step is not to use too much water!

Whenever you “re-work” the mould repair and cause it to become dampened, add those elastic bands and again leave the mould to dry out completely.

Do whatever is needed, again and again, until you are happy that your repairs are about as good as you can get. But do not obsess about joints that are not quite right or that there may be a little hole that needs filling because this can also be addressed after your first firing.

You’ve now got the point where you’ve done your best with the repair. Well done. It’s a messy and fiddly job and you probably had to do it several times to get it right. Patience is a virtue! Now is the time to convert the weak clay glued joints into a stronger mineralised clay joints.

For my first firing I happened to be slumping some bottles and there was an unoccupied space on the kiln shelf to fill, so that’s what I did first. Slumping at around 700 degrees Celsius is hardly a full fuse but I found that even this low temperature was enough to fire the clay enough to begin to mineralised and form an acceptably strong repair. Another advantage of this firing schedule was that it was conveniently slow and gentle.

After this first firing I found that some of the original mould pieces were not aligned exactly. I could feel the joints with my finger nail and decided that they would result in unsightly lines on anything made in this repaired mould. I also spotted a tiny little depression where three piece or mould met. So, the obvious answer was to attempt a “improvements” repair.

The improvement repair was nothing more than to apply a little more clay slip to areas that needed them. Again I wet the mould before applying more clay slip but this time there was no need to worry about the mould falling apart because the joins were already quite strong. Again, you may need to do this several times until you’re happy with your final repair attempts.

With the final repairs done, leave the mould to dry out (yet again) and then put it back into the kiln to produce what we hope will be a good-as-new repair.

Job done. An expensive but broken mould can be brought back into service!

Some Extra Notes

You may be concerned about the strength of the joints and that a ceramic mould is being repaired using clay at a temperature that is much lower than a potter would have been used to produce the original mould. Let me explain my understanding and the consequences…

Although I am not a potter, I am aware that clay undergoes various predictable chemical changes at different characteristic temperatures and that each of these chemical changes happen only slowly. Each of these chemical changes we can think of as progressing the clay from a weak substance stepwise towards a very strong ceramic substance. This also explains why potters use long and slow schedules compared to our “in and out quickly” schedules. Forming a strong crystalline structure is good for pottery but is bad for glass work! Yes, I’m thinking of devitrification!

So, by firing our repairs in a glass kiln at a relatively low temperature and for a relatively short time we only cause the clay repair to incompletely take the first few steps of the pottery firing process. From this I think there are three practical consequences:

  1. We have not fired the repair to a high enough temperature. This means the resulting repair is not as strong as the original ceramic mould because the clay has not been converted to the same “final” chemical substance that the original ceramic mould is made of. This means we have to handle the repaired mould with just a little extra care.
  2. We have not fired the repair for long enough. This means the resulting repair is not as strong as the original ceramic mould because the clay was probably not in the kiln long enough to allow achievable chemical changes to be happen completely. This leads to an interesting speculation that the repaired mould may get a little stronger after being used a few times. But again, it means we have to handle the repaired mould with just a little extra care.
  3. By under-firing the clay minerals of the slip have not become as hard and durable as the original mould which, conveniently for us, means that our repair is still soft enough be sanded or scraped to address remaining defects.

When All Else Fails

If you’ve done your best but the repair fails or is not to your satisfaction then I offer a final thought…

If you can repair the mould sufficiently to achieve a close approximation to the original mould then you have something that could be used to make another mould. As they say, there’s more than one way to skin a cat.

Go for it. At the very worst you start with a broken mould and end up with a broken mould!

Posted in Experiment, Microwave kiln, Money-saving ideas, Mould, Recycling, Repair | Tagged , , , , , , | 2 Comments