How To Clean Coins

The Do's and Don'ts of Cleaning Coins

Serious coin collectors advise against cleaning your coin collection, as they value the "natural look" that uncleaned coins retain. Unless you have no intention of selling the coins and don’t mind losing their value, you should avoid cleaning them.

Why Cleaning Coins Is Discouraged

• Detectability: Professional coin dealers and collectors can easily spot cleaned coins. Cleaning often leaves visible marks on the surface, significantly reducing the coin's value—sometimes by 25%, 75%, or even 90%.
• False Improvement: While cleaning may seem like an improvement, it typically damages the coin's natural finish and appeal.

Exceptions to the Rule

In certain cases, such as coins recovered from the ground (e.g., ancient Roman coins), cleaning might be necessary to identify them. If you must clean a coin, consider gentle methods:

• Soak the coin in trumpet valve oil for 2–3 days.
• Gently brush the coin with a firm, soft toothbrush.
• Repeat the process as needed, avoiding removal of the natural patina.

Proper Coin Handling

• Always handle coins by their edges to avoid fingerprints on their flat surfaces.
• Avoid using silver or metal polishes, including jewelry polish, as they leave microscopic scratches.
• Protect your collection in coin holders or cases to prevent damage.
• Limit handling by others, as frequent contact reduces the coin’s condition and value.

Confirming Value Before Cleaning

Before cleaning, verify whether your coin has significant value:

• Use a coin price guide to look up the date and mint mark.
• If the coin’s details are obscured by dirt or stains, use a magnifying glass to examine it.
• For uncertain cases, consult one or two reputable coin dealers to confirm value before proceeding.

When Cleaning Is Acceptable

If the coins are common, have no significant value beyond face value, and you simply want them to look more presentable, gentle cleaning methods can be used without causing noticeable damage.

Safe Coin Cleaning Methods

1. Vinegar and Salt

   • Mix a teaspoon of salt into a glass of vinegar or lemon juice.
   • Place coins in the solution, ensuring they don’t overlap.
   • Leave them for 5 minutes, then rinse and dry.

2. Ketchup or Tabasco Sauce

   • Place enough ketchup (or Tabasco sauce) in a cup to cover the coin.
   • Submerge the coin and let it sit for 3 minutes.
   • Rinse thoroughly with hot water.

3. Coca-Cola

   • Pour Coca-Cola into a dish, ensuring coins don’t overlap.
   • Soak for 5–6 hours, flipping the coins halfway for even cleaning.
   • Rinse with warm or hot water.

4. Eraser

   • Rub a dirty coin with a clean eraser as if erasing pencil marks.
   • Flip and repeat on the other side. Each coin takes about 10 seconds to clean.

Final Note

Cleaning will not improve a coin's grade, the standard used by collectors and dealers to evaluate its condition. In most cases, leaving coins untouched is the best way to preserve their value and authenticity.