So my first thought was that the clay that I was attempting to fire still had internal moisture that would need to be dehydrated. After a few quick searches on the internet I found that it was suggested to keep the kiln at low temp over night before firing. So last night after putzing around in the shop for a while I set the kiln to 150, vented the kiln by propping open the top and the peep hole and let it go for 12 hours.
I immediately wanted to set the kiln to fire up and bisque fire it. But I wasn’t going to be home today and didn’t want to risk another explosion while it was unattended. I’ll sit down tonight and fire it so I can watch it for the first few hours. After the temperature creeps past the boiling point I’ll feel better about leaving it run.
Hopefully it’s not another clay bomb. I just put a malformed bowl in there so it’s not a huge deal if goes kablooey.