Deborah Bouchette on tue 3 aug 99
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How thin is too thin?
I've been through dozens of resources trying to find information on =
predicting
slumping in a clay body. Tichane's book is one of the few that even mention
slumping, but still not much of a help.
What I'm looking for is...if a piece slumps in a firing at its =22normal=22
maturation temperature, can you fire it lower and keep it from slumping =
(yes,
I'm trying this...)? If it's actually melting when it slumps, is this =
partial
or total vitrification, even though the clay is not getting to its =
maturation
temperature? Does having a glaze on (appropriate for the firing temp) =
increase
the risk of slumping (it seems to in my tests)? Does a mat or gloss glaze =
make
a difference (haven't tried this yet)?
Any gurus out there?
By the way, thanks Clayart for info on local reduction a while back...I now =
have
a cone 9-10 copper red out of my electric kiln by taking a Coleman recipe =
and
adding 1=25 silicon carbide fff to it. It's got some salt scumming that =
I'll try
to get rid of by putting a little vinegar in the batch, but my better half
actually =2Alikes=2A the scumming effect :-) I got a nice celadon, too--the=
color
was perfect but I didn't like the glaze texture. More tests, more tests. I
thought when I graduated that I was done with tests=21
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now 15 years in Oregon
Deborah Bouchette
principal=40aleatoric-art.com
http://www.aleatoric-art.com
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