More on Cleaning

As it applies to coins, cleaning is a catchall term. There is cleaning and there is cleaning. No matter how a coin may be cleaned, the purpose should be to enhance its appearance. Collectors can have very different opinions about appearance. Prior to cleaning any coin, carefully consider what you hope to accomplish. There should be an obvious and important reason for tampering with the surfaces. When cleaning coins the most effective thing you can possibly apply is common sense.

Based on my experience, the best way to remove dirt from the surface is to soak the coin in warm water combined with a small amount of the kind of soap you would use to wash a baby. Never use harsh detergents! You can speed the process by gently prodding the undesirable material with a wet Q-tip, gliding it over the surface without pressure. (Don’t use Q-Tips on proof coins, only business strikes.) Such a bath should do nothing to alter the coloration or condition of the coin. When finished, rinse the coin under a stream of cold water and pat dry without rubbing the surface, using a soft towel.

Stubborn, non- water- soluble substances, like tape residue and PVC contamination can often be removed by soaking the coin in rubbing alcohol. There are other solvents, such as acetone, which will also do the job, but which can be harmful to the user if handled improperly. It would be irresponsible of me to recommend its use. Leave experimenting with chemicals to the experts! I cannot stress enough the importance of being cautious and patient when attempting even the most benign forms of cleaning. I know of one dealer- -fortunately it wasn’t me- -who decided to remove some hazy film from the surfaces of a scarce twenty dollar gold piece. All went well until he began to dry the coin. It slipped from his fingers, dropped to the floor, and gained a large rim bump.

As with grading, developing the skills to detect coins with altered surfaces requires plenty of hands on experience. Every series of coin, in every grade, has a certain look, when an internal “look” isn’t right,for the experienced numismatist, a warning alarm goes off.

Even if I stayed up nights working on it, I doubt I could ever develop a standard formula to establish values for cleaned coins with obviously altered surfaces. What I can positively state is, I will rarely buy a coin that has lost its attractiveness due to cleaning. If I can’t find something to like about the piece, I usually pass. Early in my career I learned about the traps, always set and baited, ready to catch the unsuspecting bargain hunter.

As you may have noticed, many uncirculated coins don’t looks as bright and new as the day they left the mint. Most of the metals used to make coins naturally oxidize when exposed to air and moisture. Sulfur, used when making certain types of paper, can greatly speed the oxidation process.

Using a non-abrasive liquid tarnish remover to restore mint brilliance on silver coins has been a standard practice for many years. Most dealers and collectors do not consider dipping to be the same as cleaning. As a rule, when properly done, dipping a silver or gold coin that needs it will not adversely influence its value. Please keep in mind that there can be important exceptions to this rule. Attempting to change the appearance of a coin always entails some risk.

If you are not well acquainted with the dipping process let me offer a few suggestions. Practice first using common silver coins. It is unwise to dip deeply toned coins, the results are too unpredictable. Even the pros are hesitant to do this! Dilute the dip with water. A solution of one part dip and three parts water is still strong enough to remove tarnish from most coins. It may take a minute longer but is far safer than using full strength dip. Never leave a coin to soak in even diluted dip. When dip residue is allowed to remain on a coin, in time, ugly brown spots or stains will appear on the surface. Coin dip is a mild acid that can be neutralized by immersing the coin is a solution of water mixed with a small amount of baking soda. When you’re finished, carefully rinse the coin under a stream of cold water.

I would strongly recommend that you only dip coins, with obviously unattractive toning. Toning suggests originality and many collectors prefer an original appearance, even if this less than beautiful.