How to Professionally Clean Coins

Cleaning Your Coin

• 1

  Before pondering the methods of coin cleaning, determine the type, year and worth of the coin about to be cleaned. If the collector is too hasty to clean the coin, then its worth can actually drop as much as 90 percent!
  The reason for this abrupt drop in worth is that many collectors see the patina, the greenish discoloration that builds up over time, as part of the overall aesthetic value of the coin. Because coins aren't graded solely on their type and year, a naturally occurring patina is part of the value as well as a form of protection of the coin's surface.
  However, if the collector has no mind to trade-in, sell, or invest in the coin, then cleaning offers a clear and polished picture suitable for any mantel or lucky charm.

• 2

  Hold the coin by its edges so as to avoid any prints or caustic oils from fingerprints from tarnishing the face. Hold it under running warm water for about a minute. It is best that the water has some pressure to it. After all, the coin has passed hands for a good many years. Make sure not to rub it as doing so can weaken the tone of the coin, which will produce an unsightly and lackluster effect.

• 3

  If there are still some bits of tarnish, rust or dirt deposits, or any other unsightly mark still on the coin, then a good soak is in order. Depending on the coin and how blemished it is, this process can as little as a few hours or up to two weeks.
  First, determine from what material the coin is made. Gold can be soaked in hot, soapy water. Bronze, silver, copper and nickel can be put in distilled water (never use tap as that carries its own debilitating minerals) or olive oil (not virgin olive oil).
  If the grime persists, silver, copper and nickel can also be submerged in white vinegar. For silver coins, a five-minute lemon juice bath is also good.
  Put the coin in the prepared bath, wait for results, and repeat the process if necessary.

• 4

  Once the soak is complete, dip the coin in hydrogen peroxide or malt vinegar. Next, hold the coin, once again, under warm running water for a few minutes. If the coin is visually satisfactory, then proceed to the next step.
  If the coin is still lackluster, then some hand washing is in order. Use a very soft bristled toothbrush and lightly scrub the surface of the coin with dish soap. Rinse the coin frequently so as to avoid any scratches from loose dirt.

• 5

  Pat the coin with a lint-free cloth, lay it down on a soft, dry towel. Don't wipe the coin dry.
  Use a toothpick and a magnifying glass to spot clean the coin.