Scorched fiberboard - what'd I do wrong?

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Carol Cohen
Posts: 18
Joined: Wed Mar 26, 2003 6:07 pm
Location: Cambridge MA
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Scorched fiberboard - what'd I do wrong?

Post by Carol Cohen »

Okay, you guys have talked me through the kiln retrofit shelf height problem in a different thread, and THANK YOU a whole lot -- I moved everything up higher in the kiln, found a big piece of 1" fiberboard to put on top of the brick columns and shelves, to make a space only 5" high, and the new ceiling elements took the heat in that area (5" x 18" x 36") up to 1400 in 30 minutes, and all my small bits of test glass slumped nicely, on their curved stainless-steel sheets.

But oops, what's that burning smell? There's black scorched areas on the fiberboard under the stainless steel pieces! What did I do wrong? Should I not have put the metal directly on the fiberboard? Should I have put sand, or thin flat bricks, on top of the board and under the steel?

(BTW about that 1400 degrees: the shelf is so high that it's above both peepholes, and I couldn't see in, so I let the temp go to what I figure will be the maximum ever, for my uses. I usually slump my glass at 1150.)

Obviously I don't know enough about how to use fiberboard. Please tell me!
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