Is it possible, that the top layers are a total of too thick? A rule says: "counter-enamel and top-enamel should both have nearly the same thickness as the metal-ground.

Thank you for your reply, Edmund. 

Hmmm..... So you are saying that  the thickness of the glass on front and back should be similar to the gauge of metal, so that the "sandwich" balances?

It looks to me like the counter enamel on the affected pieces is a bit thicker than the top layers, as the pieces are domed and that concave space completely filled. I had to give up on adding more on top, as the opaque color underneath would bleed through the cracks in the transparent when I tried to fire again.

The metal used is either 22 or 24 gauge. One piece is about 2 1/2 inches long and bullet shaped, and another is 1 inch, shaped like a violin. I have read that shape can affect how enamel reacts. Is it also possible I need to choose more symmetrical forms?

Alicia

Thanks, Trish....I will try it again with more counter enamel, and report back with my results!

Alicia

Hello All,

I have been having some trouble with cracking when layering Thompson's Woodrow Red over Orient Red (on copper), and am not sure why. According to their color charts, both are medium firing.

I am torch firing....Pieces have a counter enamel on the back and have been domed slightly, on not-too-thin metal. I do make certain to properly clean the pieces between firings, and have tried backing my flame away slowly at the end of firing to slow the rate of cooling.   

I am doing a couple of layers of the opaque first, and then when I add a layer of transparent, the cracks appear. Any ideas?

Thanks,

Alicia