How To Clean Your Old Coins
Most genuine coin collectors agree that there are a few basic guidelines to cleaning coins. Although there is quite some debate about whether or not they should be cleaned, however if you choose to clean your coins, the principles are fairly simple.
Avoid any damage at all costs, similar to the Hippocratic Oath taken by doctors. Most coins already have a certain amount of wear, exposure to the elements and coins pounding together in a bag results in corrosion as well as nicks and scratches. Don’t worsen the situation once you have purchased a coin for collecting or trading purposes. Proceed with extreme caution.
The same principle applies when deciding upon a method for cleaning your coins, if leaving the coin alone might result in worse damage because of dirt, corrosive chemicals or other factors; then clean it very gently.
The point to cleaning a coin is not to make it look new and shiny, just to stop damage from corrosive materials, for instance the green stain on a copper coin is copper oxide which is a form of rust.
When making the decision to clean your coins, the material you use to clean them depends on what it is you want to remove. Some ordinary household ingredients may be used quite safely.
Ensure that your hands are washed and the coin is laid on a clean working surface and test any method you are to use on an ordinary coin first before trying it on a collectible.
Liquid dishwashing detergent can remove surface dirt. If soaking the coin does not work, then put a small amount of detergent on the face of the coin and rub gently using the thumb and forefinger. Clean each coin individually, keeping them separate to avoid dings and scratches.
Lemon juice is useful in getting rid of oily marks particularly those made by unwashed hands. A short soak in lemon juice will do the trick without any rubbing, but removing oily marks will expose the surface of the coin to air and this leads oxidation. The oil serves as some form of protection.
Coins should be air-dried, however if you must rub them, rub gently using a soft cotton cloth similar to those used to clean eyeglasses. These are extremely non-abrasive.
Consult a coin dealer before using any kind of tarnish remover, you could lower the value of a coin by removing tarnish and always use a stain remover that is specifically designed for coins.
In very rare cases, a serious coin collector may make use of electrolysis, but bear in mind that most coins are not cleaned or polished. Home kits are available for the purpose of cleaning coins, and it is possible for you to put your own kit together, but these should be used extremely carefully.
Just remember, consult an expert coin dealer before you clean a coin, you could be devaluing your coin by your attempts to improve the appearance of it.