When NOT to Clean Coins
- Numismatic or Rare Coins: Never clean coins with collector value; cleaning reduces their value by removing the original surface patina.
- Ancient Coins: Removing patina can destroy their history and accelerate “bronze disease”.
- Proof/Uncirculated Coins: Cleaning will destroy their luster.
- Using Abrasives: Avoid baking soda, toothbrushes, toothpaste, or harsh chemical dips.
When (and How) to Clean Coins
Cleaning is only acceptable for modern, low-value, or heavily soiled/encrusted coins.
- Distilled Water Soak: Soak in distilled water to loosen dirt, then pat dry with a soft cloth.
- Soap and Water: Gently wash with mild soap and warm water.
- Acetone Bath: Use 100% pure acetone to remove PVC residue or organic debris, allowing it to air dry.
- Metal Detector Finds: Use olive oil for long-term soaking to remove “crud”.
Note: If you are uncertain about a coin’s value, do not clean it.