WarmGlass.com

I was making a mask out of Bullseye. Fused too layers of glass with assorted decorative pieces on top. Fused nicely, annealed for 30 minutes. Used Paragon kiln. When I went to slump it over a wall sconce mold I had purchased at BEye, it cracked in two at approximately 340 degrees. I was slumping at 300/per hour.
Any idea why it split in two? I had a piece of clear/black streaky in the middle of the bottom layer. Any advice/thoughts will be greatly appreciated. Thx - km

Thermal shock. Slow down on slump firings. Brock

try the same piece at 150 per hour or even slower if your surface is uneven. That should solve it.

Been there.

Barbara