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Immersion copper plating as science project

Q. I am working on a science project for school using copper pennies, salt and vinegar [in bulk on eBay or Amazon (adv.)] solution to give an iron nail a copper finish. It doesn't make it silver. It makes it copper color. But you should see what happens to the pennies after I left them in the vinegar and salt solution for 4 days. The outside of the pennies dissolved, left holes in places. I call it mutating. What is used to make a penny? Can you help me? My science project is due at the end of this month.

Thank you.

Teddy [last name deleted for privacy by Editor]
- Vero Beach, Florida

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.

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

Q. Dear Mr. Mooney,

I just wanted to let you know I am in the 6th grade. I was reading some of the other letters from students doing the same copper plating project and got answers to some of my experiment questions. I found out from Dr. Petersen about the hydrogen bubbles. A girl wrote about the amount of copper in pennies changing because of the cost of copper. But I still don't know what they're made of. This science project will really get crazy if I start putting the dates of the pennies in my experiments. In one experiment the pennies that got holes in them were new and shiny(1996-2001), the other experiment the pennies were older and dirty. There must be other reasons for this "mutating". Not all pennies from the same year dissolved so I'm confused. Does this give you enough information to help me?

Thank you. Your friend with the same name, Teddy sometimes.

Teddy [last name deleted for privacy by Editor]
- Vero Beach, Florida

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.

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

Q. Hi. I am a mother helping my son who is in the 5th grade do a immersion plating project. in our project we will be using an ammonia [on eBay or Amazon (adv.)] and salt solution, and we won't be using electric current. in our project it calls for iron nails to be plated. Our question is, why can't we use a steel nail. Or can we?

Jamie Shamblin
parent - San Jacinto, California, USA
January 17, 2012

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.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey
January 18, 2012

Immersion copper plating brass keys

Q. Can brass keys be copper plated electrolessly? This is for a decorative art purposes, nothing commercial. I wish to sink a lot of brass keys I have in copper sulphate [on eBay or Amazon (adv.)]and plate them. So far I have been unsuccessful but I am aware of someone who has done it in the internet but the website disappeared (old unmaintained website), so I know it can be done, I just can't remember how it was performed, don't know how.

John Mayer
- Miami, Florida
January 26, 2016

January 27, 2016

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.

Marvin Sevilla
- Managua, Nicaragua

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


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - 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).

Marvin Sevilla
- Managua, Nicaragua
January 28, 2016

May 16, 2016

Mr. Ted, I would like to add a video I just made about this subject, I finally had some time to do it.

Maybe it can be shown here? Thank you.

Marvin Sevilla
- Managua, Nicaragua

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