today we fired the bisque kiln for the second time this week. we were down to knowing that it would be done in about two hours so jeff set the timer on the kitchen stove to remind us to shut it off... it's an old kiln without a kiln sitter or fancy computer stuff... just a timer. jeff was still in the studio working while i was getting stuff for dinner ready... i checked the pyrometer and noticed that the temp was dropping (yes we have the pyrometer on a long leash so we can read it in the kitchen!). i knew exactly what happened. the timer on the kiln shut it off. out the back door i went to turn it back on. i got busy in the kitchen again and of course the next time i checked the kiln it was a little hotter than we like to bisque... it was at about 1915 degrees. we should be still be ok.
i was a little mad at myself for not resetting the kitchen timer and it reminded me of something i saw on another potter's website this week. this potter relied on her kiln sitter to shut off her kiln... well it didn't. she melted all of her pots, popped the elements in the kiln, cracked the shelves and the posts. a VERY expensive mistake. she was firing a bisque to ^06 and she estimates that the kiln fired to ^10 (jeff says to cause that kind of damage to the kiln elements and shelves it was probably a higher temp that ^10).
...the moral of my story is...never trust a kiln sitter!
and this little kitten (a Dirt Works Pottery resident) has nothing to do with this post, but he sure is cute!
Two potters I know use bars instead of cones-they bend and so trip the switch and turn off the kiln.
ReplyDeleteNot sure if you could fit one to an existing kiln.
We have two kins for sale over here if you would like to add to your frustrations.
ReplyDeleteWith those kilns I bypassed the cone setter and use a pyrometer- but we don't leave them.
I know just how long it takes me to forget to check something.
I too know of folks who have melted down there kilns and shelves.
Speaking of which time to check the kiln!!!!
i have the timer on the kiln set to our typical bisque time but never ever trust it... i always use the pyrometer and never leave home or go to bed (i know people that fire at night while they are sleeping!). i forgot to nudge up the timer on the kiln this time... we did a slower bisque because of some thicker tiles and a few pots that weren't completely dry.
ReplyDeleteThose sitters aren't fool proof either, electricity can be tricky. I can't imagine a kiln getting so hot as to melt all that's inside oh my what a disaster that would be.
ReplyDeletei havent done pottery since i was in school and blew everyones pots up becuase there was air bubbles in minei dont know how i did that but thats my memory of pottery
ReplyDeletekbos2hm - oh no... it wasn't your fault! pots don't blow up because of air bubbles... that is a myth that some people still believe. your pot blew up because the teacher didn't wait for everything to dry completely. if you think things may still have moisture you have to fire very slowly.
ReplyDelete