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overfired bisque thoughts

updated tue 25 jan 05


Brad Sondahl on mon 24 jan 05

I was firing a bisque yesterday. I use an electric kiln with a
kilnsitter with timer. I didn't feel like bending over (as in recent
back spasm) to check the timer, so I just cranked the timer over a ways
and fired away. When I checked it a few hours later, I found the trip
lever had flipped, but had not disengaged the kiln. The result was
probably cone 8 bisque. Having had nearly everything that can with a
firing go wrong through my career, here's the observations I've had
about it. First I will say that dealing with cooked bisque ware is about
as fun as jumping in a cold lake on a spring day, so I put it off about
half a day. But I finally jumped in...

1. What caused it? (Crucial) I let the trip lever drop again and
noticed it had enough friction to drop slowly, which inhibits the whack
it makes when it hits the button. I WD-40'd and oiled the little pins
that it swings on, hopefully stopping the problem for a good long
time. Replacing that assembly would be a good idea next clay order...

2.What to do with the pots? Usually I thicken my glaze buckets by
taking a bunch of water of the top before stirring them, and glaze them
sort of normally (by dipping). Because the drying time is greatly
accentuated, I try to glaze about 4 boards of pottery at a time instead
of one, hoping the first glazed will be dry enough to handle by the time
the last has been dipped. This means spreading the glazed ware all over
the studio while doing it. It also means that when you pick them up,
hoping they're dry, they won't be, and you'll remove finger sized
patches of glaze from them. In this case I just go ahead and sponge off
the bottoms, and touch up the bad places with a brush. The other
innovation I added to today's struggle was to stick with one decoration
for the whole mess-- a cheap green glaze that looks good even if a bit
thin (which is going to happen).

3. So now they're firing, and probably a few of them will be seconds,
but not the whole mess. Well, customers like seconds anyway...

Among my other insanities, I like old movies from the 20's and 30's, and
I think it's one of those Fred Astaire Ginger Rogers musicals (Great
music and dancing, weak plots) they sing (what no doubt was inspiring
in the Depression), "I pick myself up, brush myself off, and start all
over again."
Still good advice.

Brad Sondahl--

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