I finally started leaving my blown pieces in the kiln overnight. No more cracks.

3 comments

3 Comments

Let the kiln cool down slowly overnight to avoid stress cracks. This slow cooling lets the glass relax without any sudden changes in temperature. For example, if you take pieces out too soon, they can develop hairline fractures that ruin the work. I found that adding a hold at a lower temperature before shutting off helps even more. It makes the glass more durable and ready to handle in the morning. Plus, you save time by not having to babysit the cooling process.

oscarl762d ago

Adding that lower temperature hold is smart, but linking it to @blake829's ramp-down advice really locks in the durability. It gives the glass time to even out all the way through, so no sneaky cracks form later. Otherwise, you're just making fancy junk that falls apart.

blake8292d ago

That hold is key for annealing. Try ramping down from 950 to 500 over a few hours before you shut it off completely. It lets the glass settle at a molecular level. A slow, controlled cooldown like that pretty much eliminates thermal shock.