Shakudo Plating

Q: I wish to plate shakudo onto a copper substrate. Shakudo is a copper/gold alloy (96% copper/4% gold). The parts will than be patinated resulting in a dark purple/black color. Is this possible? W. Y.

 

A: Your question is not the typical question I receive. For those of you not familiar with shakudo, it is a Japanese alloy made of 96% copper and 4% fine gold. The natural patina of this material is a dark, almost black color. It naturally darkens when exposed to water, air and the oils on your skin.

Gold/copper alloys can be deposited from electroless baths. The components of this type of electroless bath are usually copper sulfate, the tetrasodium salt of ethylene diamminetetraacetic acid, potassium gold cyanide and formaldehyde. As far as I am aware, there are no commercial electroless baths available for this type of plating. I am aware of two papers that appeared in the 1980s that discuss the electroless deposition of gold/copper alloys: A. Molenaar, J. Electrochem. Soc., 129, 1917 (1982) and A. Molenaar and B. C. M. Meenderick, J. Electrochem. Soc., 132, 574 (1985).

There is one reference to plating gold/copper alloys using conventional electrolytic plating baths in the Russian literature prior to 1960.

The bottom line is I don’t think you can do this. Perhaps one of our readers has additional information on this process and will enlighten us on the plating of this alloy on copper or other substrates.