Is it a bad thing to soak a silver coin in acetone?

Jim P. asks: Is it a bad thing to soak a silver coin in acetone for several hours? Will this action cause a grading service to not slab the coin as “cleaned?”

Note: The Coin Doc never recommends cleaning or using dangerous chemicals as part of participating in the hobby of collecting coins and paper money. Many coins are ruined by cleaning whether by chemical or mechanical means. The answer below addresses a question about the use of Acetone by one individual. Also, there are professionals in the fields of archeology and numismaitics that care for coins that have been under the earth or sea for long periods of time. These people are trained in the art of preservation and restoration.

Acetone won’t hurt a silver or gold coin and it will dissolve many impurities that are sitting on the surface, like dirt and PVC residue. It will not affect toning (patina) or remove metal from the coin. You only need to rinse the coin in cool, clear water after briefly soaking the coin in acetone. Put the coins on a sheet of aluminum foil to dry. Do not rub, or blot the coins with a cloth or paper towel.

Since the surface metal is not affected, this will not cause the coin to appear “cleaned”. Note that acetone will not “cure” or improve damage already present from PVC or from previous cleaning. It is just a solvent. The coin may still be rejected by third party grading services.