Old plaster

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Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Old plaster

Post by Jan de Jong »

Hello, Can I use OLD plaster which I did store in a plastic jar with lid, for casting ..... plaster, silica flour and chamotte. Jan
jim simmons
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Location: Hillsboro Oregon
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Re: Old plaster

Post by jim simmons »

If it is still in a powder form, there is absolutely no reason not to use it.
It is an inorganic compound so there is no expiration date.
The other Jim
Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Re: Old plaster

Post by Jan de Jong »

Thank you Jim. But I did read on Internet that Plaster can be used for about 4 month, so therefore my question. Jan
Buttercup
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Joined: Mon Jan 28, 2008 5:22 pm
Location: S.E. Queensland Australia

Re: Old plaster

Post by Buttercup »

I've read that, too, a few times. Is it a myth put about by the manufacturers? Or is there more to it?

Here's some chat about it:
http://www.potters.org/subject82013.htm

I've got some that must be ten years old. I was thinking of putting it in the kiln before I tried to use it. Would I be wasting my time ? It's cheap enough to replace, I just don't like waste.

Jen
Peter Angel
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Joined: Fri Oct 31, 2008 9:26 am
Location: Newtown, Sydney, Australia.

Re: Old plaster

Post by Peter Angel »

Look at the very top of the bag of plaster and see if there are small hard balls of plaster.

These balls are plaster that has already hardened.

Sift them out. The rest of the plaster is fine.

Pete
Peter Angel
http://peterangelart.blogspot.com/

A bigger kiln, A bigger kiln, my kingdom for a bigger kiln.
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