Cones 10 and 11 melting at same time

[Lbegley 11]

I was firing a cone10 gas kiln yesterday and both the cone 10 and 11 started going over at the same time, both on the top cone pack and bottom.  I’ve never seen this before, and wondered if anyone knows why this would happen.   

[neilestrick 3,457]

That happens. Heat work works in strange ways sometimes. Cones 10 and 11 are only about 18 degrees apart at a climb of 108F/hr, so they often drop at almost the same time.

[Lbegley 11]

Thank you!  I did fire faster than usual. That must have been it.