Nan Rothwell on sat 3 apr 04
I find that salt makes the cones melt a tad faster/earlier. I have tested
this by putting cone pads on the same shelf next to each other, with some in a
sagger and some exposed to salt. But they didn't vary by a large factor --
maybe half a cone. I suspect that salting later in a firing cycle would have
less of an impact.
Of course, I can't see the saggered ones until the kiln is unloaded, so they
might vary more along the way than after the cool-down. I say this because in
my experience, a full cone differential that is visible when I turn off my
kiln often narrows to less than that after cooling. It feels like the cooler
spot catches up after the kiln is off ... maybe some of you technical types can
explain why? Perhaps because cones melt as a factor of both time and temp,
and if the kiln stays hot for a while after shutting down, the time factor evens
them up? This tendency to even up after the firing is over was more
noticeable in my old hardbrick kiln, which cooled much more slowly than my current
kiln that's built with insulating brick...
Nan
Date: Fri, 2 Apr 2004 13:09:17 -0700
From: BJ Clark
Subject: Salt and Cones?
Does adding salt to a gas kiln change the chemistry to effect at what
point the cones bend in any way? Another student at my college says we
are over firing out salt fires and it's because when we add the salt,
the cones become unreliable, is this true?
Thanks In Advance,
BJ Clark
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