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I have an opportunity to purchase a quantity of 20x30" pottery kiln shelves inexpensively. The description I have of them is that they're heavy. The original owner was a potter and is now deceased. The shelves are sitting in a barn and are being sold by the new owner of the farm. He knows nothing about pottery or kilns and can't give any leads to their composition or where they were purchased.

Apart from checking for flatness when I view them, what else can I do to determine what material they are and whether they are suitable for glass? Are there any "brands" molded into, say, mullite shelves? Even though the price is right, I don't want to end up with a bunch of "ugly" kiln shelves that will offgas and give bubble trubble.

Carol

I don't know about checking for "brands" for composition. Good ole thick/heavy shelves would tend to be pretty flat. As for fumes.... I've never had a problem with it. BUT you really need to make sure that the shelves are clean with absolutley no glaze stuck on them. It's nearly impossible to remove as the glaze has a tendency to eat deeper into the shelf with each glaze firing. Even using a kiln shelf wash these little specks can be a problem unless you plan to use fibre paper type shelf liner!
Good luck

Some potters use silicone carbide shelves. They're black, heavy, and rough. If you're going to bend glass in forms those shelves can work as the glass won't touch them, but you'd have lots of trouble fusing on them, unless you put stainless sheet down first.

Carol,

I'd not only check for the flatness , but I'd check that the surfaces are not gouged or pitted. If they are, there will be marks on the backs of your pieces. Kiln wash does not appear to adequately fill in the gouges.

Good luck.

Cheers,

Bob

Carol wrote:I have an opportunity to purchase a quantity of 20x30" pottery kiln shelves inexpensively. The description I have of them is that they're heavy. The original owner was a potter and is now deceased. The shelves are sitting in a barn and are being sold by the new owner of the farm. He knows nothing about pottery or kilns and can't give any leads to their composition or where they were purchased.

Apart from checking for flatness when I view them, what else can I do to determine what material they are and whether they are suitable for glass? Are there any "brands" molded into, say, mullite shelves? Even though the price is right, I don't want to end up with a bunch of "ugly" kiln shelves that will offgas and give bubble trubble.

Carol

Thick shelves R a bit of a heat sink n heavy

I got 1/2 ones

Check shelves 4 cracks hold wit one hand tap it with peice of wood or knuckle if it rings its OK if not then cracked
But loose bat wash will sound odd as well

Brian