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Electroforming Bath operate at room temperature

February 6, 2009

My best regards to all plating colleagues. I am using wax as a mandrel material to produce different products from silver electroforming bath which work at room temperature and I am succeeding. Now I want to prepare a gold electroforming bath which will work at temperature less than melting point of wax mandrel, i.e. 50 °C . I woud like to be able to electroform to (800-1000)microns; bright finish is not necessary. Can any one help me ? What formulas, what the operating conditions pH value, and the type of anodes? No problem if the formulas is for application of alloy or pure gold plating.
Thanks,

Aaed Mohhy
Plating shop employee - Baghdad, Iraq

Temperature of the gold bath should not be a problem. Most pure, neutral ph gold plating solution temps are under 50C (122F). When you are plating 3.2 mil (800 microns) I would suggest a auto chem feeder to add so much gold per ampere hour. As far as formulas, it is best to go with a proprietary gold plating process. Because you have to buy the gold salts from a supplier, you may as well go with their bath. If it is a reputable supplier or distributor they can assist you with tech service. If you make the bath up on site, it will cost a lot less than buying a ready to use plating solution. As far as anodes I would use Platinum clad niobium mesh. Good Luck!

Mark Baker
Fellow Plater - Syracuse, NY, USA
February 10, 2009

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As far as anodes are concerned, you should use gold. The most common electrolytes are cyanide based, but I would recommend you talk to your chemical supply house before you embark on making your own. Supply houses spend a lot of time and money developing new and better baths that will give you better performances. In the long run they are the best option. Some will even supply non-cyanide baths and this is a major advantage.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
February 11, 2009