Pulled a slab bowl/plate piece this morning and about 4 hours later I heard the dreaded ping… sure enough, big crack 😩
Trying to troubleshoot what went wrong.
Details:
Slab built + well compressed
Dried under plastic for a few days, then air dried
Bisque: slow to cone 04
Glaze: slow to cone 5 with a 10 min hold
Where I might have messed up:
I cracked the kiln lid at ~250°F and took the piece out around 175°F.
Google is pointing to cooling being the issue, but curious from people with more experience:
Is this thermal shock/dunting?
Is 175°F too hot to unload for larger pieces?
Do you all just leave the kiln closed until it’s fully cooled?
I usually make smaller pieces and have gotten away with opening earlier, so wondering if scale is what got me here.
Any insight appreciated 🙏