Holding back from checking a piece too early saved my bowl

I had a thick bowl in the kiln, and the schedule said 12 hours to cool. I almost peeked at 8 hours because I was curious. But I waited, and when I took it out, it was perfect with no stress cracks. The glass was about half an inch thick, so it needed that full time to relax properly.

4 comments

4 Comments

spencera771mo ago

Oh man, I've been there. The wait is brutal, especially when you're excited to see how a piece turned out. I rushed a thick paperweight once, pulled it way too soon because I just had to know, and I heard that awful ping from the studio an hour later. A stress crack right through the center. It taught me that the schedule is there for a reason, especially with thicker glass. That thermal stress needs time to even out, no way around it. Your story is a perfect example of why patience pays off.

the_finley1mo agoMost Upvoted

Actually @spencera77, it's more about the controlled cooling during annealing than just time. The schedule manages the stress, not just the clock.

jamesf291mo ago

My kiln manual says cooling times are just guides, not strict rules. I've opened it early many times with no problems. The type of glass and how the kiln is sealed can change cooling speed. Waiting is good, but worrying about every minute is too much. A stress crack might be from bad annealing, not just checking early. People follow schedules so closely they ignore what actually works.

michael_green4420d ago

Half an inch thick and you almost peeked? @jamesf29 is nuts, that's just asking for a crack.