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Electroplated copper wipes off of nickel?

I tried electroplating copper on to a nickel and the metal seemed to have gone on but when I took it out to wipe the electrolyte solution off the metal came off with it (or whatever was coating the coin). I followed the directions on this website for plating with copper. Does anyone know what went wrong?

Garrett B
Student - Fresno, California, United States
May 12, 2008

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May 13, 2008

Hi, Garrett. When copper is electroplated onto something, electrons flow out of the cathode (the object being plated), and "reduce" the copper ions that are in solution to solid copper metal. If the cathode is clean and "active", the copper will metallurgically bond to the nickel. But this reduction reaction can proceed though even if the cathode is dirty or covered with tarnish. In that case there is no bond to the nickel.

It is widely known among industrial electroplaters that it takes a special, high-acid striking process to get a really good bond to nickel. I have successfully plated quarters per our instructions, but I realize the bond is not "industrial strength" -- it's good enough for a student science project. But I haven't tried plating onto nickels. It's possible that the different alloy composition of a nickel makes the adhesion worse, but it's also possible that you didn't fully clean the nickel or that you touched it (you must wear plastic gloves during and after cleaning).

It would be great if you ran the experiment again and proved that you can get sufficient adhesion to a quarter or a dime but not to a nickel. Then your project would be quite special, rather than just like what ten million kids already did :-)

Copper foil is manufactured by electroplating onto a stainless steel belt that has been treated to assure a lack of bond. After plating, the copper is just pulled off the belt as a foil.

Regards,

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