More
on Cleaning
by
James Halperin
Many thanks to Chuck from North
Carolina and Joe M. for their provocative questions about cleaning and dipping
coins. These are always hot topics so it seemed best to share my response to
them with you.
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 less
than beautiful.
James Halperin
is co-chairman of Heritage Rare Coin
Galleries and Heritage
Numismatic Auctions, of Dallas, Texas, the world's largest rare coin
dealer and auctioneer. Jim has been one of the top coin traders in the world for
the past 25 years. He is also the author of two best-selling futurism novels, The
Truth Machine and The
First Immortal.
