nikom chimnok on fri 11 dec 98
Dear Clayarters,
I would like to thank everyone who responded to my query a couple of
weeks ago about how to warm a downdraft kiln. After our usual fireman
cracked 4 out of five 34" pots by warming the kiln with the door open, I
brought out all the responses to show the management that I was not alone in
thinking that the burners should be lit after the door was closed. So I got
permission to fire one kilnload according to my (our) theory.
I took it up slowly--less than 50 degrees Celsius per hour-- since
this was unbisqued clay with glaze on it. After 12 hours it was almost 600
degrees, but the color told me that the bottom of the kiln was still cooler
than the top. At this point I went to bed, warning the usual fireman to go
slowly to 700 degrees, to make sure everything in the kiln was really past
600. At 700 they let 'er rip, going up 200 degrees in a single hour, and
then finishing off at more than 100 degrees per hour.
The result: nothing broken.
Since the big pots came through unscathed in 18 hours, today they're
trying a load of small stuff in 12 hours instead of the usual 16 or 17.
Which means the firemen will be able to work tomorrow instead of sleeping
all day, as usual. I think we're making some progress.
Thanks,
Nikom
In Thailand, where for the last three nights the temperature has dipped to
60 degrees F., and we're all dressed up with socks and jackets and calling
it winter.
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