Metal finishing Q&As since 1989

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Cores for electroforming

I am looking for a material to serve as a core in electroforming that can be later removed from the plated material.

Gregory Wahl
Clarkson University - Potsdam, New York
2002

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If the shape and dimensions permit you to slip the electroform off of the mandrel, a stainless steel mandrel can be used. If not, you can use a wax mandrel and melt it out, or an aluminum mandrel and dissolve it in caustic.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

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There are many different types of core available, depending on what you are doing. If the core can be designed to be pulled (i.e., it has draught angles) from the electroform, it can be made from stainless steel. If it cannot be pulled, then it has to be dissolved out. You can then use aluminium, polystyrene or ABS. There are also conducting putties available, but they are difficult to get. I believe a company in Germany makes them, but I do not know who. You can also use waxes if the plating conditions allow it. The only limitations are that the core must be electrically conducting and stable in the electroforming bath. Obviously if you use a polymer, it must be metallised. Look in any standard text on electroforming.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2002