Expert: PAPAJACK - 9/27/2008

Question
I collect and do not clean my coins. My buddy buffs hers with a dremel but doesn't use any kind of chemicals. I told her I wouldnt do that.. it sure works great and I am curious does this too damage the coins? Thanks so much!

Answer
Hello Jonathan,                

Let me first state as a Coin Collector that coins are worth much less to coin collectors after having been cleaned. This includes any buffing or “Whizzing” or any surface alteration!
There is usually no reason to clean a coin, unless the substance on the coins surface is destroying the piece (like acid, PVC damage etc.). Any coin that has ever been cleaned will sell for much less.

True coin collectors don't recommend cleaning coins at all.
When a coin is cleaned the original surface is removed thus removing the original mint surface and luster that the purest collectors want to see.
The cleaned surface also allows other contaminates to attack the surface. And the cleaning may deposit other particles on the surface.

Coins that are naturally toned (especially silver coins) bring higher prices than cleaned coins. Usually double the amount. Also if the coins have an unusual blue, olive, or rainbow colored toning they sometimes can be sold for many times their usual price.

Cleaning of Bronze, Copper, Silver or any coin renders it virtually valueless! Collectors of Copper would rather have a dark deep chocolate brown specimen or spotty brown than a cleaned coin. Even rubbing a coin with a very soft cloth can leave minute scratches on the surface that will adversely affect collector value.

For those who can see the difference;
To improve a coin's appearance it sometimes in the past was acceptable--on a very limited basis to gently swish it in a diluted solution of pure soap, rinse with distilled water and allow to air dry.  (Or pat dry lightly with a very soft cloth) Never use any type of commercial jewelry polish on coins. These compounds contain abrasive grit that will mar their surface, and if used often will eventually wear away the metal. The same advice goes for "home remedies" such as vinegar, lemon juice, tomato juice, etc. All will do more harm than good.

Feel free to make me one of your favorite experts at this site. Ask any question on U.S. Coins.

Below is an excerpt from a professional society (authorized by the US Congress) in reference to cleaning coins:

"Rule number one of coin collecting is "DON'T CLEAN YOUR COINS." Improper cleaning will reduce the collector value of your coins by 50 percent or more so don't clean your coins.

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Good Luck

PapaJack