Bill Kielb Posted July 18, 2022 Report Share Posted July 18, 2022 (edited) 4 hours ago, kristinanoel said: so I'm thinking it's that irregular cooling problem. If my mitigation tactics don't solve the issue, I'll likely finish out this order and then abandon this glaze on this form! Im not entirely convinced about the severity of uneven cooling because of the mass of shelves and air gaps under the wares etc… it’s just not something personally I have been able to measure using an infrared device periodically. There generally is just not enough air movement in a sealed kiln. Anything is possible though ……. but removing the site ports during cooling can definitely provide a pathway for enough air flow to cool things unevenly. I would definitely leave them in and let the mass of the kiln brick, shelves and wares give up their heat naturally by radiation and conduction. If you have a downdraft vent, turning it off at the top of the cycle before cooling is probably a solid idea as well and saves energy. Just a little data to add, we measured the cool down rate of several kilns and firings. The interesting takeaway, the end of firing is probably on the order of 400 degrees per hour so most vulnerable to uneven cooling and by the time of quartz inversion ((prox 1000 deg) say 50 - 70 degrees per hour. Most wares do just fine firing 200 - 500 degrees per hour on the way up so no surprise quartz inversion issues on cooldown are probably rare and turning off you fan before the end of firing could prove most helpful. Data for a sealed kiln Edited July 18, 2022 by Bill Kielb Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
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