Debating the 'cold garage' method for annealing small pieces

I've been working out of my unheated garage studio in Denver, and last winter I got tired of waiting hours for my kiln to cool down for small pendants. On a whim, I tried putting finished pieces directly into a metal toolbox filled with vermiculite, then closed the lid and left it in the cold garage overnight. The next morning, they were perfectly annealed and stress-free. Some folks say this is risky and only a proper kiln cycle is safe, but after 30 pieces done this way with zero cracks, I'm starting to think it's a valid shortcut for small, simple items under 1/4 inch thick. Has anyone else experimented with alternative annealing for minor work, or is this just asking for trouble down the line?

3 comments

3 Comments

black.wesley3mo ago

Vermiculite just slows cooling, doesn't anneal it.

the_miles3mo ago

Totally agree, black.wesley, learned that the hard way.

brooke_nguyen651mo ago

That's a rough spot to be in, and I totally get why you'd try the cold garage trick. Waiting hours for a kiln to cool just for a small pendant is a pain. I think you're onto something for thin, simple pieces, but I'd still be a little nervous about relying on it all the time. Vermiculite might slow the cooling enough for tiny stuff, but it's not the same as a controlled anneal cycle. I'd worry about stress hiding in there that only shows up later after a few months of wear. Still, if it works for you and you've done thirty without cracks, that says something.