Coin Cleaning is OK – Sometimes
Don’t clean your coins is universal advice given to collectors of all ages. Many resist, but for some of us the temptation is too great. Through trial and error plus any hand-me-down secrets they learn, some may become fairly good at restoring the eye-appeal of their coins. I have no doubt that a few skillful folks probably slip over to a darker side of this pursuit as they find that cleaning and fraudulent surface alterations often lead to an increased value of the piece they worked on. Thus both conservationists (good “doctors”) of all skill levels and “coin doctors,” (those that fraudulently alter and repair coins) exist side-by-side and are judged by the quality of their work. Coin conservation – proper cleaning - consists of removing undesirable contamination from a coin’s surface in such a way that defies detection and preserves the coin. Conservation is not improper cleaning (a botched job), restoration or any kind of fraudulent alteration of the coin’s surface. Putting aside the “coin doctors,” any person with longtime experience in the art of conservation will have actually ruined a coin or dozens of them over time. It is the nature of the occupation. Anyone who claims they have never ruined a coin while trying to improve it is probably lying or they have not tried to push the boundaries of their knowledge.
Virtually anyone can learn to clean a coin properly. The process is simpler and faster with some instruction. All it takes is a few tools and chemicals. Figure 1 is a typical home or coin show hotel conservation lab. The difference between this “lab” and even a semi-professional one with a fume hood, filtered air and a deionized water system is many, many thousands of dollars. Yet, an experienced collector or dealer can achieve good results much cheaper. Running water, a vented room, fluorescent light, a stereo microscope, an ultrasonic cleaner and some chemicals provides an excellent set-up for an amateur.
If you decide to send a coin to one of the third-party grading services (TPGS) that offers conservation services instead, the first thing they must do is examine your coin to see if there are any “fixable” problems. That’s what you are paying for initially. Obviously, TPGS conservation does not involve repairs of any kind such as smoothing out scratches or rim nicks. Where I work (ICG), the $10 conservation charge covers that initial exam. There is no additional charge if we conserve it. You can check with other grading services to see their rates. After the exam, many coins are left as is because, in the opinion of the person doing the exam, cleaning the coin in any way will make it look worse or the coin is ruined so badly that it cannot be improved. The people making the final decision (especially on high-ticket items) are very experienced in this regard. On a few occasions they have told me to conserve a coin I did not wish to touch, and my conservation came out beautifully.
The coins sent in for conservation can be sorted into six basic groups with only four of them requiring any action. Each of the four requires different chemicals, treatments and techniques (mechanical or chemical).
1. Coins that don’t require any cleaning because they are fine as they are.
2. Coins that will become less attractive if they are touched at all.
3. Coins having chemical changes to their surfaces such as oxidation or stains.
4. Coins having a “soft,” sometimes organic, form of contamination.
5. Coins having man-made substances on their surface such as lacquer.
6. Coins having “hard” types of contamination such as debris and encrustations.
Most experienced collectors/dealers can tell in just a few seconds which of the six possibilities they are dealing with. Much of the time they can do it without any magnification. The best of them know when not to do anything (options #1 and #2 above) or just a little. Sometimes less is more. A quick rinse under tap water, a splash of acetone, a blast of compressed air, or a few strokes of a jeweler’s brush may be all that is attempted. Other times a full conservation is needed – turning a darkly toned or dirty coin into a gem worth many multiples of its cost.
Examples of the former case (less is more) is removing flecks of debris from the surface of an old copper cent or picking the dirt from the recess of a gold coin’s legend.