Last Updated: Jun 19, 2018 Views: 4419
Hello! Thank you for your question! Below are listed several resources that you may find useful, along with some excerpts.
From James Kervin, Pâte de verre and kiln casting of glass, 2nd completely rev. ed (Livermore, Calif.: GlassWear Studios, 2000), pp. 116-117:
Making Glass Pastes: You make a glass paste by mixing your frit with some water or water-based binding agents like those used in glass painting, pottery glazes, or enameling. The paste can then be brushed or packed it [sic] into place in your mold with a palette knife. When mixing up your paste you want to mix it to a smooth consistency like that of a thick paint. It should be easily picked up with a brush but at the same time it should be able to just as easily drip off of it.
Water alone can be used to bind the paste and burns out clear (at least in most cities) but lacks the pastiness necessary to hold the glass frit in place on near-vertical surfaces. Oils as binders are not generally recommended because they can carbonize and there is usually no place for the carbon to escape as the oil burns.
Of course there are exceptions to every rule. Dona Milliron has told us that she has had good success using squeegee oil which hardens almost like a glue and has not had any problems with either carburizing or color reduction. If you are going to use oil-based binders it is advisable to use them sparingly, to add a soak at 1000 degrees F to burn them out during the firing and to have a fairly permeable or porous mold to prevent trapping organic vapors.
Traditionally one part of gum Arabic (from the acacia tree) dissolved in one part of alcohol and then mixed with twelve to twenty parts of warm water was used as a paste binder. Be careful with this though because it can also carbonize and “fry,” that is cause bubbling or cracking in the glass, if the solution is mixed too strong. It’s a pretty strong binder.
Other traditional gum binders include: gum tragacanth, dextrin, vee gum and CMC (sodium carboxymethyl-cellulose). They are all mixed similarly to gum Arabic and can be found at many ceramics supply stores. If you can not find anything else you can always thin down some Elmers glue with water and use that to hold your frit in place. It works just fine.
A good binder found in most households is a diluted solution of Knox gelatin. It doesn’t take much gelatin to get the glass to stick and you can even drink the leftovers to get those chrome-molly fingernails we talked about earlier. Another simple water-based binding agent is sodium silicate dissolved in water. Any of these mixtures will harden when air-dried so you should only mix as much as you need.
Thompson Enamels makes a good binding agent called Klyr-Fire. This is a methyl-ethyl-cellulose based binder that has given us good results. It burns out clean, is cheap and you don’t need a letter from the governor to buy it directly from the manufacturer or its distributors. No mixing is required and it can be used straight from the bottle. Brushes used with it can be cleaned with water afterwards. The paste does not harden as much as some of the other mixes though and may move around some on you.
Glass pastes painted into your mold can be used to achieve very subtle shadings of color through the use of a palette of colored frit or incorporation of metal oxides or enamels. The addition of 10 to 20% by volume of 80 to 120 mesh enamels is sufficient to create sufficient color density when used with a clear frit.
Enamels work best with the low-temperature, high lead (20 to 25%) glasses because their flex points are similar. Otherwise you may have to adjust the coefficient of thermal expansion of the enamel to fit the base glass frit that you are using. This can be done by mixing it with the desired base glass, melting the mixture in a crucible, and refritting it by pouring the melt into water. Make sure that you mix the component well before starting and allow the melt to sit at high temperature for a little while to allow good mixing of the components….”
From Keith Cummings, Techniques of Kiln-formed Glass, reprint (London: A&C Black, 2007), pp 108, 113:
Describing Argy-Rousseau's pate-de-verre method:
Once the mould was made, it was turned on to its side and carefully filled with finely crushed and washed glass, surface details first, usually using the finest grains for such areas. The mould was filled a few grains at a time literally pushed into the profiles of the mold surface with a range of wooden and metal tools designed for the purpose by Argy-Rousseau. These ensured a ratio of glass to space in the mould that was extremely high which each piece being forced to lock closely with its neighbors. This allowed Argy-Rousseau to keep the glass accurately in the details of his decoration. The glass grains were moistened with distilled water (*) to lubricate their movement together and the horizontal area presented by the mould lying on its side, filled layer on layer until a sufficient thickness of wall achieved, usually a few centimeters. This was held in place by a thin layer of gum, and the mould rotated to present a new section for filling; this would continue until a complete internal layer was complete. After drying the area inside, the glass layer was filled with powdered asbestos (absolutely not recommended), a lid of mould mix placed over the open end and a new, complete layer of mould mix cast round the entire form to hold it in place. This was placed in the kiln with the base of the vessel at the top, and fired for up to a week. Because of his painstaking method of mould packing, the glass settled very little but it was helped in this by two things: The base of his objects was slightly thicker than it needed to be to allow for some top-up effect if the gals in the main body settled and the powdered asbestos, despite its lethal qualities, did not stick to the glass and gave off a gas which expanded during firing and pushed the glass into the details. The inside of Argy-Rousseau casts show a shiny skin which is a characteristic testament to this....
...a small amount of distilled water (used in preference to tap water so as to avoid the risk of lime-scale contamination) was used to act as a gentle impermanent lubricant to encourage the grains to slide more easily over each other, and remove any danger of dust inhalation.
Philippa Beveridge, Warm Glass: A Complete Guide to Kiln-Forming Techniques: Fusing, Slumping, Casting (New York: Lark Books, 2005) uses methylcellulose glue (MCG), mixed according to the manufacturer's instructions, with the ground glass for making a flat piece of pate de verre: "Select the appropriate granulation of glass next (in this instance, the finest and the next larger size), along with the colors of ground glass that you want to use. Mix each color with the same volume of clear glass, and then with the previously prepared methylcellulose glue. The pate de verre...is packed into the...[mold] with a spatula. Then press it down (here, we used the handle of the needle tool) so it fills in the shapes and eliminates air between the particles...." (p. 118).
For more detail, see Cummings' research in Stewart, Max, Amalric Walter, and Keith Cummings, The Amalric Walter Research Project: The Techniques and Methodology of Amalric Walter 1870-1959 ([Wolverhampton]: University of Wolverhampton, 2007):
This publication presents the findings of an Arts and Humanities Research Council funded project carried out at the University of Wolverhampton's School of Art and Design between November 2005 and December 2006 (p. 1).
[Project objectives were] a. to contribute to a greater understanding and knowledge of the complexities of pate(s)-de-verre in general, and the work of Walter in particular; b. to generate and present an account of Walter's probably procedures, illustrated by examples and supported by data, in a form that enabled their replication; c. to estimate the contribution to Walter's technique of his background at Sevres, and time at Daum. The intention was to illustrate Walter's mastery over his medium in a way that would enhance his status, and through practical advice allow his discoveries to serve as a stepping-stone for a new generation of practitioners (p. 3).