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cordierite advice needed

updated tue 13 jan 98


Dan C Tarro on fri 9 jan 98

I need some advice from the group on one inch Cordierite shelves. I am
still putting together plans for our kiln building this summer and have
to make some decisions on the shelves now. I assume that warpage is a
fact at cone 10 and 11reduction on these, what I'm not sure of is if they
will warp more on a long narrow shelf in contrast to one more square. I
have my choice of 12"x24 or 20x16. Also, are these usually stilted in all
four corners to help prevent warpage or like si. shelves with the usual
tripod? I have never used these shelves at these temps and any advice or
your experiences would be greatly valued.
Thank you,
Dan Tarro
Oak Tree Stoneware
Ham Lake, Minnesota

Dan Tarro
Oak Tree Stoneware
Ham Lake, Minnesota

KLeSueur on mon 12 jan 98

In a message dated 1/9/98 5:28:47 PM, you wrote:


I've used corderite shelves (Thorley) since 1976. I use 14 x 24 x3/4". I fire
to a flat cone 10 with 11 sometimes tipping. Reduction. I stilt on a triangle
pattern-one in the middle of the long side, one at each corner of the opposite
long side. I love these shelves and wouldn't use anything else. I don't wash
my shelves so I can flip them when warping begins. Warping has never been a
serious problem. I'm told that fast firing can contribute to warping, but my
firing cycle is about 12 hours. Not especially fast but not slow either.

Good luck,
Kathi LeSueur