Immersion copper plating as science project

A. Hi Teddy. If your project is to copper plate the nails, you should probably use pieces of wire instead of pennies as the source of the copper. You can buy a foot of "Romex" at a hardware store for about a quarter; that will give you 3 feet of copper wire since it includes a hot, a neutral and a ground. Wire is almost perfectly pure copper (for reasons you'll learn when you study electricity).

Pennies are made of copper plated zinc. They corrode terribly and are a poor source of copper, due to the thinness of the plating and the contamination from the zinc, although pre-1983 pennies are solid copper.

A. Our letters crossed in the mail. But modern pennies (1983 and on) are made of zinc with a thin copper plating. As soon as the copper coating is perforated, the zinc will corrode quickly. You will be much better off using copper wire as the source of copper.

Yes, even at my age, I'm "uncle Teddy" to my nieces & nephews.

A. Hi, Jamie.

You can use steel nails, but it's best if you sand, then scrub the nails first to make sure nothing else is on them. From your point of view steel and iron are essentially the same thing.

The teacher may refer to iron in school rather than steel because iron is one of the 92 naturally occurring elements whereas steel is a man-made mix of the element iron with very tiny amounts of other elements. Sort of like grain and protein will be on the food pyramid, but not mixes of them like french toast. Good luck.

Regards,

A. Assisted immersion plating of copper over brass is very possible, not only that, but also over other more noble metals like Silver and gold.

I have given some of my sterling silver a beautiful rose gold appearance (I have yet to produce rose gold plating). This following method will work for just about any other metal more noble than copper or copper itself including brass keys (first test I made was over a brass key that I later silver plated).

I use this immersion plating formula for steel, copper, silver and it gives me a very good and thick coating. 20 grams of copper sulphate per litter of battery acid [affil links] (about 35% Sulfuric acid in water) 5 grams of Sodium Oxalate (Citrate or Acetate would also work, we need a copper complexed solution) I prepare that by adding Oxalic acid to sodium bicarbonate (about one to one ratio)

This formula has worked for me on steel for quite some time now. but as you may see it's copper and trying to plate a more noble metal with it by immersion it's nearly if not impossible. But that's why there is a term I would like to call, Assisted Immersion plating. by contacting the metal to be plated (Brsss or Silver) with a less noble metal (steel plate on my case) than that of the plating solution one can achieve a very good and adherent coating.

In this case the metal to be plated is brass but could be silver, gold, nickel; the plating solution is a Copper Oxalate complex (EDTA, Acetate, Citrate also provide good results). The plating enhancer is a metal that is less noble that copper. I have used zinc and steel with good results.

The container should be big enough to plate the amount of keys you will be plating when laid on their flat surface without touching or interfering with the coating of the other keys, put a steel sheet (about 30 gauge or more, or any piece of steel that will laid flat and fit on the container) put the keys flat on the steel sheet and pour the copper solution. Allow the pieces to sit there for 20 minutes to get a thick coat of copper, the coat is thick and dull but with polishing it will reveal a beautiful copper color. On Silver it looks like rose gold.

This process is very basic and can be modified to suit one's need, like spraying larger bronze/brass items.

Hi Marvin. Your posts on this and related subjects (semi-immersion/semi-catalytic plating) have been fascinating and informative. Thanks!

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
January 2016

You are welcome Mr. Mooney,
I was wanting to add that by contacting the noble metal with a base metal of lower electron potential will momentarily (as long as it kept in contact) turn the noble metal into a negative electrode (Cathode) causing the copper to deposit from the copper plating solution in an electrolytic way (Positive electrons migrating to the negative charged noble metal that has become the Cathode).