Letter 24100

Electroforming onto Styrofoam  

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I intend on using a piece of styrofoam as the base material to silver electroplate/electroform.
My intention is to subsequently enamel onto the electroplated/formed piece.

Will the electroplating/forming process dissolve the Styrofoam?
Since the enameling process requires the metal to be heated to about 1450-1475 degrees F to
flow the glass enamel onto the metal surface; removing the underlying styrofoam material would be desirable.

Mark Hofman
glass-on-metal enameling art - Irvine, California

Removal of the styrofoam before enameling is not desirable - it is essential! Styrofoam is polystyrene and this is not designed to stand temperatures above about 100 C (212 F). However, it can be used as a mandrel for electroforming. All you have to do is metallise it with a suitable process (for instance, silver spray or electroless nickel or copper) and then electrolytically thicken the metal with whatever metal you desire. You then dissolve the polystyrene in a suitable solvent and you are left with a free standing electroform. Suitable solvents for polystyrene are methyl chloroform (banned under the Montreal Protocol!) perchloroelethylene, most other chlorinated olefins, Acetone [link is to product info at Rockler] (highly flammable) and numerous others. Once you have removed all the polystyrene, you can start to heat your metal to the enameling temperatures. You may, however, upset your neighbors by producing lots of smells and they may report you to the environmental agencies, so make sure you have all the correct equipment to do the job!

Trevor Crichton R&D practical scientist - UK