1967 Tiki mug mold - Collecting Tiki

S Saint-Thomas Member Knoxhell Joined: Sep 26, 2002 Posts: 39	S Saint-Thomas Posted posted on 06/03/2003 Oh, I forgot this info--sorry for the double post! Plaster is not water soluble. It is a hydrate of calcium. That water does not go away unless you break the molecular bond by heating to a certain temperature. In theory, you could "revitalize" old plaster by heating it in an oven. Same goes for a mold. If you were to heat it up to, oh, say about 500 degrees, it would fall apart as the H2O is driven off. The reason plaster molds absorb water is due to the porous nature of the molecular structure. The water is actually going into the spaces in between the plaster molecules.

Oh, I forgot this info--sorry for the double post!

Plaster is not water soluble. It is a hydrate of calcium. That water does not go away unless you break the molecular bond by heating to a certain temperature. In theory, you could "revitalize" old plaster by heating it in an oven. Same goes for a mold. If you were to heat it up to, oh, say about 500 degrees, it would fall apart as the H2O is driven off.
The reason plaster molds absorb water is due to the porous nature of the molecular structure. The water is actually going into the spaces in between the plaster molecules.

Post #37000 by Saint-Thomas on 06/03/2003