nickel electroplating on nickel

[knowlittle]

The metal keys of musical instruments are typically made of nickel silver (Cu-Zn-Ni 60-20-20) electroplated with copper flash and bright nickel. When the nickel coating is worn, the keys are stripped of nickel and re-electroplated. Nickel stripping is a manual process, I mean expensive. Is there an inherent risk of double electroplating? What if I skip the expensive manual stripping process? Thanks.

 

[EdStainless]

Without careful surface prep there is a real risk of the plating flaking off.
Because the underlying material is not very strong or corrosion resistant you can't blast or use an acid stripping method.

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Plymouth Tube

 

[tomwalz]

There is not much risk. You are almost certain to have problems. Plating is not a physical process. It is a chemical process. You need to have the two chemicals in contact with no interfering layer.

Remember in chem lab when they made you wash things really well and rinse them 7 times. Same idea.

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[knowlittle]

Thanks for the replies. I am not sure if I properly worded my question. I am curious if the remaining nickel has to be removed.
If I don't remove the nickel, I will have base metal (basically brass), copper flash, and nickel coating. Can I put copper on the dissimilar metal assembly and electroplate it with nickel? Thanks.

 

[EdStainless]

If you are down to bare brass in places you may have to strip.
If it was just worn Ni you could lightly etch it (reverse polarity) and simply plate over it.
The Cu should stick to the Ni (both under and over) but wouldn't that give you uneven plating thickness?
You could try on some damaged equipment. The resulting surface may be too uneven and have cosmetic issues if you just Cu flash and then Ni plate over the existing worn plating.

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