This is not the first time this has happened. I am using 1/2 shelves, & have been staggering heights. Shelves are off the bottom of kiln & I always take care not to block a heating element. I could however, probably add more space between shelves & wall of kiln. And I was told by kiln repairman, not to remove top peephole. Kiln is vented w/ Orton vent. Not sure about zoned kiln... I'll investigate. Thanks, Lucille.
My electric kiln fires an entire cone higher in the bottom of the kiln than the middle or top. It is a Paragon J-27 & has only fired 20 times. Firing to cone 5 with a hold of 20 min. makes for beautiful pots, but the middle & top shelves don't vitrify. The pyrometric cone shows the bottom fires to cone 6. Today I fired a Cone 6 program w/ a 5 min. hold. I didn't pack the bottom of the kiln tightly but it still it fired to cone 7 (and ruined my pots). What to do? What to do? Thanks!