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Copper plating on steel

A supplier suggested a simple method of plating steel parts with copper as a way to protect them from the elements. A solution of copper sulphate ⇦ this on eBay or Amazon [affil links] & sulfuric acid were combined and sprayed over sand blasted steel plates. The solution deposited a nice coating of copper very quickly and was allowed to dry. I washed the parts in a neutralizing solution as the last step. The results were disappointing, but it wetted my interest in plating with copper.

Is there a better method to do this? Will copper be able to protect steel better than zinc plating?

Joe Cobb
- Midland, Texas
2006

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2006

This "immersion plating" method is not a very robust method of plating because it will be very very thin (the moment there is any copper on the part, there is no more driving force to continue the reaction) because it is a "substitution" reaction whereby copper plates out of solution only to the extent that iron goes into solution.

Copper does not protect steel well at all because: think of what happened to get the copper on the part (iron had to dissolve). So the copper will stay deposited on the part by forcing the steel to preferentially corrode. Zinc is usually a better plating for that reason.

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