Letter 26021

The process by which pennies get their copper coating [Canada] 

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I am a grade twelve student. In my chemistry class, I am required to complete a research paper regarding the applications of electrochemistry to the process by which pennies (post-1982) get their copper coating. Do you know the commercial means (not a classroom or small-scale experiment, but for the purpose of public use) by which this is done? Is the zinc disc submerged in a certain electrolyte containing copper ions? Does the process require the use of a voltaic cell to force reaction? Thank you for your time. Any help will be greatly appreciated.

Jaime B.
student - Edmonton, AB, Canada

Yes and yes. The zinc blanks are electroplated in a copper plating bath in plating barrels. See "An Introduction to Barrel Plating" by Frank Zemo for some text and pictures which clarify what barrel plating is about. Please do not ask Mr. Zemo any follow-up questions; instead post them here. If you are ambitious, get a copy of "US Mint Claims Copper Plated Coin Makes Economic Sense" from Plating and Surface Finishing [link is to product info at Amazon] magazine, July 1981.

 
Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ

I am a senior and am need to find out how to copper plate a coin or key. I dont know why if you have the copper strip why the blue copper stones?

Jamie C.
- Willow Springs, Missouri USA

If you are thinking of plating the key just for educational reasons, please see http://www.finishing.com/faqs/school.html as a start, Jamie. You don't need the blue stones, but you do need to create a blue solution because if the solution is not blue, it has no copper in it, and if it has no copper in it, you can't plate copper out of it.

 
Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ

I want to answer or follow-up on this subject publicly (in non-commercial fashion).

 

My company is a supporting advertiser at finishing.com and we want the contact information to reach the inquirer privately.

 

I want to post a new question or inquiry of my own on a different subject.