From: REMOVE_THISdwilkins@means.net (Don Wilkins)
Newsgroups: rec.crafts.metalworking
Subject: Re: Aluminum casting molds
Date: Wed, 18 Oct 2000 06:54:14 -0500

On Tue, 17 Oct 2000 21:30:24 GMT, d.watson2@worldnet.att.net (Prowler)
wrote:

>,;Only thing I know right at the moment, without looking into some books
>,;is you must be very careful about plaster.
>,;If it has the least bit of dampness in it, is it will explode!
>,;
>,;So be carefull. Theres a way to dry it in a kitchen oven , but you
>,;must do it for days I think.
>,;
>,;Dennis
>,;
>,;
>,;On Tue, 17 Oct 2000 20:01:50 GMT, jollyrogerx@my-deja.com wrote:
>,;
>,;>Is it possible to cast aluminum in a plaster mold? This would be easier
>,;>for me than using sand for my project.


I would not recommend it because of the water of hydration present.

 You can get them dry but that doesn't mean you have removed all of
the water. Plaster of Paris e.g. is the half-hydrate of calcium
sulfate. That water is released at 163 degree Celsius and would not be
treated kindly by molten aluminum.