John I. writes: what is the safest way to remove the film that coins get when they have been in a plastic flip too long? is dipping safe and if so, in what. I would really appreciate any assistance you can give me.
Storage is a big issue for coin collectors. The soft flips are generally safe but they will break down chemically if they are exposed to sunlight or placed in a very hot environment for a extended period of time. The chemical breakup releases hydrogen sulfide that can attack the surface of most coins. It will virtually destroy copper coins and leave silver coins spotted or scarred with other evidence of corrosion. The decaying flip also will leave an oily residue on the surface of the coin.
One of the safest ways to remove the oily mess (for you and your coins), is to purchase non-oily nail polish remover (acetone) from your drug store. Just allow the affected coin to soak for a while and then rinse it with cold water for at least one minute. The advantage in using this method is that it will not affect the surface metal of the coin, just what’s on top of it. Do not use “Jewel Luster” type coin dips as they remove metal from the coin.