A few weeks ago I fused 2 standard pieces of glass without any issues. I used a 9" X 9"clear for the base and topped with 4 squares of transparent. (2) 004217 adv green,& jade grit w/adv grn streamers, and (2) 001417 emerald green.
2 days ago I attempted the same fusing with the same program and types of glass. The result was, what looked like, a finely cracked piece. As I went to lift it from the kiln it started to literally crumble.
Program used: 350-1050 , hold one min
450-1500, hold 10 min
Full-900, hold one hour
130-750 , off
Any ideas as to what happened?