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sitter problems in electric kilns

updated thu 31 oct 96

 

Craig Martell on mon 14 oct 96

Although I no longer glaze fire in electric kilns, I did for many years at
cones 6, 8, &
10. My experience with sitters was that even when well adjusted they would
not produce the results I wanted. I found that it is best to use visual
cones to judge the
temperature and heatwork being done in the kiln. Electric kilns are
notorious for
firing hotter in the middle, where the sitter is located, giving cold tops
and bottoms if
one relies only on the sitter. We usually place visual cones in the top and
bottom of
the kiln and load the center heavier, to slow temperature rise a bit in the
middle. One
can then vary heat settings at each kiln ring with the switches to get a more
even firing if there are cones to observe. Electric kilns with 2 1/2 or 3"
walls cool very fast
too and it is sometimes advisible to soak the kiln at peak temp. for an hour
or so. We would accomplish this by turning all switches to med. once the
firing cones had
gone down. It might also be worthwhile to place several cones inside the
kiln for the
first few firings to determine where cold spots are. These cones can be
placed in areas that are not visible through the spy holes.

I hope this info is of some help,

Craig Martell-Oregon USA