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Dissolving copper from mandrel

2005

Dear People,

I'm looking for a way to dissolve a brass mandrel after electroforming a nickel shape without attacking the nickel.
Thanks in advance,

Patrick O'neill
Gudel Cointechnology BV - Amsterdam, The Netherlands

Is there a reason the mandrel isn't made of wax or aluminum, Patrick? You may well have a good reason, but you may have inadvertently started off on the wrong foot, so we ought to ask.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005

Ted's right. Using brass as a disposable mandrel is not a good start - you should use wax, plastic or even aluminium. You could try soaking it in hot sodium hydroxide and hope the brass dezincifies and lets you pull it out, but if the part has not been designed to be pulled, then you have a big problem!

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2005

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