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alumina hydrate in kiln wash

updated thu 28 may 98


Marni Turkel on wed 27 may 98

I use a mix of 1 part EPK and 2 parts alumina hydrate (by weight) for my
kiln wash and I highly recommend it. I fire to cone 4-5 with Thorley
shelves in 4 electric kilns. If I fired higher, I would probably try 3
parts alumina hydrate. The kiln that gets the most use has approximately
120 glaze firings on the current set of elements with no problem. The old
elements came out withough problem. The wash needs to be renewed every 10
to 15 firings (brushing on another coat). If the glaze on a piece runs or
the bottom sags and touches, the kiln wash is stuck to the piece, but the
wash is not stuck to the shelf, and all the shelf needs is a touch-up of
wash in that spot. When it is time to flip the shelves I use a disk sander
with 80 grit paper to quickly remove all of the wash. Unlike silica based
washes, or commercial ones like Axner's very expensive one, it doesn't
permanently adhere to the shelf, pull the shelf up with the wash if the
glaze touches it, and it doesn't flake.

Marni Turkel

>Date: Tue, 26 May 1998 08:27:34 EDT
>From: Betty Burroughs
>Subject: Alumina hydrate
>----------------------------Original message----------------------------
>I wonder if any of you have had a problem with using alumina hydrate in kiln
>wash in an electric kiln. A friend of mine is convinced that the a-h she
>used in wax resist as well as kiln wash on the shelves destroyed the
>elements. When they needed to be replaced they came out in tiny pieces
>instead of in one long coil. It took hours of pulling out all the fragments
>with needle-nosed pliers. She says she remembers reading on Clayart a while
>back that alumina hydrate gave problems in an electric kiln. Can any of you
>enlighten me here?? I have just had my shelves sanded and am looking for a
>good dependable wash recipe. TIA!
>Betty Burroughs
>Victoria, BC

Marni Turkel
Stony Point Ceramic Design
Sonoma County, California