WarmGlass.com

I have a heavily carved plaster mold made from hydrocal. I want to made a reverse mold from it in a plaster /silica mix which can be fired under glass. I am thinking of using mold soap as a release agent. Has anyone done this with sucess? Any one have a better thought? I don't dare damage the original mold in order to produce it's reverse.

Thanks in advance

Thin clay slip will definitely work but you may lose too much detail. It seems to me that I've used Murphy's Oil Soap for this. That's what I usually use on my molds but I'm not generally pouring plaster against plaster. I'll have to check my slipcasting book back at my studio.

murphys oil soap works for me. maybe you will want to pull a latex type mold off your origonal so you can duplicate it if it gets damaged. rosanna

I took a pate de verre class a year or so ago and the instructor mentioned using some pourable latex to make copies of the positive so one can make duplicates later... does anyone know what this stuff is actually called and where to get it?

Thanks,
Nancy

Nancy, try this link http://www.clayartcenter.com/synairproducts_1.htm . I bought some mold making stuff from them but haven't tried it yet.
Sharon

You can also use one of the liquid rubbers from a company like Smooth-On. Most are two parts, which are mixed together. They become rubber-like once they cure and can be used to make multiple wax duplicates of the original.

http://www.smooth-on.com

Thanks both! How exciting...... That's exactly what I was looking for. This is the thing that makes me love working with glass.... there is always more to explore and learn... now the downside is that there are always more toys to buy.......

~Nan

Nan:
Alse try Polytek. They have a great, instructive catalog and make several kinds of rubber molds. They'll also send you smaller size containers at a discount, on a one-time per product basis so you can try them out. Have fun!
Nikki