Found a way to keep my color bar from cracking when I cool it down

I was having a real problem with my custom color bars cracking almost every time I put them in the kiln. It was wasting a lot of glass and time. I tried slowing down the heating, but that didn't help much. Then I read about annealing soak times on a forum and decided to try holding them at 950 degrees for a full 30 minutes before dropping to strain. It worked perfectly on the last five bars I made, no cracks at all. Has anyone else found a specific temperature that works best for their color mixes?

3 comments

3 Comments

bennett.jana6d ago

950 is a solid spot for a lot of mixes. I had to bump mine up to 980 for some dense reds that kept giving me trouble. It really depends on the batch and the brand, idk. Finding that sweet spot for your own glass is such a relief after dealing with cracks.

adamr146d ago

Is this really worth stressing over? It's just colored glass. I've seen people lose sleep over a 30 degree difference like it's life or death. My old coffee mug cracked because I poured boiling water in it, not because I missed some perfect magic number. Sometimes stuff just breaks.

milaw146d ago

My friend's "just colored glass" mug cracked like @adamr14 said.