Coin Cleaning

Is It Ever OK to Clean Coins?

Some types of coin cleaning might very well improve a coin’s appearance, while most other methods may actually damage the coin’s surface, appearance and–most importantly–the value. If I could offer just one piece of advice to you today, it would be this: Do not clean your coins under any circumstances.
This, by no stretch of one’s imagination, will not be a how-to article on cleaning coins. Instead, we’ll discuss the methods of cleaning for those who will not heed our warning. All we ask is that you don’t come crying to us when a perfectly good coin has been ruined for all time.
We suggest to those who are going to attempt to clean a coin despite our admonition to experiment first on coins of little or no premium above the face value, or denomination. Coins found in pocket change make good test subjects. Any slight bit of mishandling or mistreatment on a more expensive coin will adversely affect it both aesthetically and monetarily.
What is abrasive cleaning? It is the process of using an acidic substance or a wire brush on the coin’s surface. The wire brush technique is often referred to as “whizzing”.
Coin Dips: While it is certainly true that a quick dip of a fraction of a second may not cause too much obvious damage, it will still remove some metal, no matter how slight. The resultant surface will have an “artificial” look. The original metal “flow lines” will be gone and you lose that wonderful “cartwheel” effect that makes an uncirculated coin so appealing.
The coin’s flow lines originate in the minting process and give the coin its reflective properties. Dipping, even for a millisecond, will reduce or eliminate these flow lines. The coin will also lose its natural mint-made lustre. Dipping, no matter how slight, may very well cause “pitting” on the surface.
Abrasive cleaning will always remove some part of the coin’s metal, regardless if you can see it or not. This is a cold fact. Abrasive cleaning is, without any doubt, the more harmful of the two methods and should never be considered.
Have you ever seen a blazing “white” U.S. Morgan silver dollar without any evidence of even a slight bit of toning? These coins are well over 100 years old and, except for the hoards released by the U.S. Treasury about 50 years ago, it is virtually impossible for any silver coin that old to be as bright and shiny. The answer is a quick dip. Toning is a natural phenomenon to any silver item, including coins. Toning is as much a part of the coin’s aging process as wrinkles are to you and me as we advance in age.
As to the dipping not lasting forever, many dipped coins that turned dark or black specks and spots in a relatively short period of time. The point to remember is that a dipped coin will either return to its previous non-dipped state or worsen over time. As to the non-abrasive cleaning method, a professionally performed non-abrasive cleaning will not, in most instances, subject a coin to lose its metal flow lines or aesthetic qualities.