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How do I tumble a copper coin

2002

I found a old copper coin with my metal detecter the size of a silver dollar. I wish to clean it enough where I can read the date and other important details. I have tried soaking the coin in olive oil for two weeks and have yet to remove the grit that seems to have encrusted my coin. I have a tumbler and have considered using it to clean the coin. What is the best mixture to use in the tumbling process?

Joey Warenzak
- Savannah, GA, USA

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First of two simultaneous responses2002

Olive oil isn't generally thought of as a good cleaner. I would suggest using a good cleaner/degreaser like Dawn dish soap and a relatively stiff toothbrush to remove the easy crud. Then try using some lemon juice to deoxidize the surface, but by all means don't tumble the coin. Tumbling will only wear away the high points of the surface - eventually leaving a smooth (and unreadable) surface. Don't leave the coin in the lemon juice too long, or it may start eating away at the copper. Hope this helps.

Dan Brewer
chemical process supplier - Gurnee, Illinois

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Second of two simultaneous responses2002

Old trick from "Hints from Helloise" try mixture of acetic acid and sodium chloride. If you can't get your hands on that, try vinegar and table salt (same thing!). Nice deoxidizer for copper without harming your coin.

Milt Stevenson, Jr.
Anoplate Corporation

Syracuse, New York