I recently fired a piece that incorprated some BE thin vanilla glass. As it was a 2nd firing and I was bringing it up to 1425 slowly, I used Spray A to guard against devit. Big mistake! The thin vanilla turned a dark mustard color, while all other glass was unaffected. Anyone know why? Do other glasses respond similarly?
I could have used it in a painterly fashion, had I known what to expect. I thought about adding yet another layer of thin vanilla and then refire to mellow the color (the mustard would show through, but not as strong), but wondered if the spray A would again affect the new layer since it would be in contact with the layer below where it was previously used.
Any thoughts?
Thanks, Sheila
Spray A & BE thin vanilla color change
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To elaborate on Ron's comment: French vanilla (BE 0137) contains sulphur. Spray A contains lead. When the two are mixed, you get lead sulphide and the mustardy color. This is a predictable reaction, so you can use it to achieve a particular effect if you wish.Ron Coleman wrote:Spray A contains lead which reacts with the French vanilla. Use borax for devit.
How you view the reaction makes it a feature or a flaw.
Bullseye's amber glasses (1137 and 1437 -- that "37" is a clue!) will react with lead similarly.
As Ron says, if you want to avoid the effect, use a non-lead bearing spray, such as borax/water or SuperSpray.
I often use Spray A as anti-devit and it always leaves milky signes looking like something inside the glass, not like grease. Here we do not have something else to buy at the glass stores. Now I bought the borax powder at the store for jewellery needs. How do you use it? Should I mix it with the purified water or another medium? And how to apply - for each firing or just once?
Thanks.
Anna.
Thanks.
Anna.
http://www.warmglass.com/making_your_own.htm#DEVIT
I add a couple drops of dish soap as a surfactant to give it some surface tension like a sticker spreader. I also apply it every time I take the piece to full fuse temps. It matures at full fuse temps and doesn't work well at any processing temps that are lower than that (in my experience).
I add a couple drops of dish soap as a surfactant to give it some surface tension like a sticker spreader. I also apply it every time I take the piece to full fuse temps. It matures at full fuse temps and doesn't work well at any processing temps that are lower than that (in my experience).