About 12 years ago, I was using the following formula Transparent 06-04 with no problems. I do a short soak, 10 min, with C 05 firing.
Frit 3195 85
Went back to doing low-fire work last year, but when I finished my old supply of Frit 3195 and started on a new batch, I began to have major problems with Tiny Bubbles in the fired glaze. Smooth surface, but fizzy, foamy, bubbly appearance underneath. So odd. My first failure firing had a whole shelf of mugs glazed with "old" glaze---fired fine, no bubbles. Next shelf, mostly mugs glazed with a fresh batch of glaze with new frit 3195 --all fizzy/bubbly (but 2 mugs with old glaze on same shelf were fine).
I use red eathenware clay body, so a bubble-free glaze is important.
Solutions I've tried:
New formula with some 3195 replaced with F 3134. Helped, but tends to go boron blue. Not good for me.
Bought new F 3195. No change.
Apply thinner. Helps, but not much.
Tried using more or less 3195, adding Silica, trying different frits and combinations with 3195 (tried 3124, etc), using less Alumina in formula, etc. Still tends to fizzyness.
I now use a clear 05 with this formula: But I don't like it as well, and WISH I could get my old reliable Frit 3195 Clear Glaze working again!
Just wondering if anybody else has noticed Frit 3195 melting differently.