In this section we will discuss the methods, ethics and practicalities of coin cleaning.
METHODS OF COIN CLEANING
I. “Whizzing” and wiping - Before chemical dips, the wire brush (hand held or on the end of a drill) was convenient to create a shiny, new looking coin. Under a loupe, however, the tell-tale parallel brush lines (“hair lines”) and the movement of metal in front of the brush wires gave letters and numbers a wind-blown appearance, a dead-certain give-away. A whizzed coin is a worthless coin, an adulterated coin. There are many sold each day on eBay, buyer beware. “Improperly Cleaned” is the leading reason PCGS and other Third Party Graders reject coins. Even a gentle swipe with a cleaning cloth can leave behind the tell-tale fine hair lines that a TPG grader will see as he “wobbles” the coin under his grading lamp.
2. Organic Solvent dip - Carbon-tetrachloride was the rage when the oldest author was a kid until its lethal side effects forced a ban on its use. Acetone, somewhat less toxic, is the current solvent of choice although it, too, must be used with respect as it can dissolve the fats in your cell membranes, cause liver rot and generally kill off your cells – not good. A little splashed on your fingers will do no harm but prolonged exposure to higher concentrations either on skin or breathing in vapors is to be avoided. Best use it out of doors or at least in a well ventilated room and certainly away from any and all flames or possible sparks.
Since acetone dissolves most plastics including plastic gloves, metal coin tongs are a must. The simplest containers for dipping or soaking coins are broad, low glass jars with metal screw caps (no rubber gasket) or one can use folded aluminum foil held in place with stout or multiple rubber bands. Note that most Q-tips have plastic cores. You can find wood-stick Q-tips via Google.
Acetone will dissolve oils, grease, oily grunge, even the green ugly stuff left behind by PVC from the older soft plastic coin holders and flips. Greasy dirt will wash away quickly but PVC residue may require days or weeks of soaking. Remember that PVC residue can etch a coin in time, especially Ni-Cu clad coins: do not expect pristine surfaces beneath the PVC gunk, especially if it is turning from green toward black.
The good news is acetone soaks do not harm to silver and clad coins, even with prolonged soaking. But there is no free lunch and acetone can give exposed copper a neon-pink coloration, including the exposed copper on the rims of clad coins. Acetone does not disturb toning and it may wash away the peculiar “fogging” and “clouding” that can attack Cu-Ni clad coins (even coins housed in TPG holders).
ANACS recently published a piece on acetone cleaning, suggesting that an acetone soak is a good precaution if there is any possibility a coin was exposed to soft plastic for any length of time. Some coin pros routinely dip all TPG submissions in acetone as a precaution.
TPGs generally insist that submitted coins be in hard plastic “flips”. While the hard plastic is free of PVC, it can scratch coins over time, especially proofs, so many coin pros insert their proof subs into small soft vinyl flips and then into the required larger hard flip. Over a few days or weeks this probably does no harm. One of the authors used only hard flips but he holds them together gently with rubber bands to prevent coin movement within the flips.
Acetone is available at most drug stores and hardware stores. Look for 100% pure acetone at Home Depot, for example, or pharmaceutical grade acetone from your drug store. Once again, acetone, like gasoline, is highly flammable and must not be used near flame or electric sparks. It evaporates rapidly, very rapidly into a gaseous form which must not be allowed to accumulate!
You will need two or three glass jars with acetone in each for successively cleaner rinse-dips. After the final super-clean rinse-dip you can let the coin air dry.
Your New England author enjoys cleaning coins in the summer when it is possible to do everything out doors or on a screened porch. When the operation moves indoors, he uses only one jar of acetone which is kept tightly sealed with aluminum foil and rubber bands. Instead of a series of cleansing rinses with acetone, he uses a series of 90% alcohol rinses and a clean cotton towel to gently wick off the alcohol of the last rinse.
Other organic solvents – There are other candidates:
- 91% Isopropyl Alcohol : (“first aid antiseptic”), available at all drug stores, is perfect for removing most greasy gunk, although a Q-tip may be necessary to gently remove clots of oily debris (remember that the coining press dies were oiled/greased frequently so many Ikes have grease/oil remnants. Some even show grease strike-throughs in which portions of the coin have no design definition because those die elements became filled with grease).
Since this alcohol is used for rub-downs, it is quite safe to work with and many coin pros routinely use it as the final rinse as it air-dries rapidly or can safely be blown away with a hair drier.
Do not use Isopropyl Alcohol that is mixed with a skin lotion ingredient! If in doubt about the purity of your organic solvent, allow a drop or two to dry in a mirror.
- Gasoline is mentioned only to put down: it is toxic, explosive, and contains additives that leave residues.
- “White petroleum”, better known as “Coleman’s camper Fuel” is an excellent non-ionic, relatively safe organic solvent that is cheap and available at Wal-Mart’s and the like. One author found it worked as well as acetone on early PVC residue. It evaporates slower than acetone which makes gentle, patient Q-tip work a lot easier.
3. Acid dip - E-Z Off and Jewel Luster are two readily available acid dips which will instantly remove most toning from Ikes. Indeed one simply dips an Ike using plastic coin tongs once or twice for a few seconds and the coin will have been stripped of its tarnish. Since continued exposure to the acid will quickly begin eroding deeper into the outermost layer of your coin, the layer that provides the luster we prize so highly, the briefest possible dip and immediate extensive flushing in tap water is essential, flushing for minutes rather than seconds. Then dip for a few seconds in water into which some baking soda has been dissolved (amount not critical, half a teaspoon in a pint is fine), and lastly dip into two rinses of distilled water or isopropyl alcohol before drying the coin with a soft lint-free cotton towel or hair drier.
If your coin room is more than a few degrees on either side of 70, the dipping time will change: for example, a swing of around 15 degrees F will double or half the time required. Thus an 80 degree dip will work twice as fast as a 65 degree dip.
Over-acid-dipped Ikes look dull and lifeless: Proofs should be dipped for no more than a second or two, BS Ike for no more than five to 15 seconds.
If you’re working with Proof coins, be very careful handling the coins and use a hair drier for drying. Experience is the best teacher so experiment with previously abused proofs!
E-Z Off is an acid solution of thio-urea and detergent so if you rinse a dipped coin in a plastic basin you will see soapy frothing for about 20 seconds: continue rinsing well beyond that point. Follow the detailed rinsing instructions given below.
4. MS-70 - Useful stuff at times, especially for Ikes. It is as harshly alkaline as the acid dips are acidic and it also contains strong detergents. Use it full strength or diluted 50-50 with water and apply with a Q-tip, gently swabbing or rolling the Q-tip over the surface of the coin (rapid is OK but no pressure): avoid scrubbing as even soft cotton with rubbing pressure can leave hairlines that are death for a fine coin.
Working with a Q-Tip gives you total control of the process and it’s actually a lot of fun to see the tarnish vanish instantly. The fun part will help you sustain the experimentation necessary to get a handle on which Ikes benefit from “cleaning” and which do not as well as leading you to the methods that work best for you.
As with acid dip, the toning vanishes instantly in most cases and a thorough rinse is the next, immediate and most important step. If you are not doing wholesale cleaning, it is safe to work with bare fingers, holding the coin by the rim and moving your fingers enough so you get MS-70 over all the surfaces including the rim. For the rinse, instead of holding each coin under running water for 10 or 15 minutes, use a plasticized wire silverware bin, the size used in kitchen drawers. Place the bin in a slightly larger solid plastic silverware bin and fill it half-way with water. Place this at your water-proof, well-ventilated and dust-free work station so you can gently lay the coin in the basked under water as soon as it looks clean, usually as soon as your Q-Tip has rotated over all three surfaces.
When you have done a few coins, or when the bottom of the basket has one layer of separated coins, place it under fast running tap water for at least ten minutes. It takes a long time for the detergent to rinse off.
Then, lift out the wire basked and dump the tap water out the solid plastic bin. Thoroughly rinse the plastic bin, replace wire bin with the coins and pour distilled water over the coins until the bin is half full – then dip the wire bin in and out of the distilled water. Dump and repeat. You now have thoroughly rinsed coins dripping wet with distilled water.
To dry the coins you have several choices. Some use a hair drier which blows most of the water off the coin and evaporates the rest. Others use a 90% rubbing alcohol dip, pouring just enough into the plastic bin to cover the coins: dip the coins in and out of the alcohol followed by forced hot air drying (hair drier) or wick-dry with a clean lint-free cotton cloth to remove most of the alcohol prior to air-drying.
To insure thoroughly dry coins one can hold each in the stream of hot air from a hair drier or gently layer them on “Jewel Cloth” and gently warm them with a light bulb for a few minutes.
You’ll develop your own techniques. One of the author’s tap water has high iron content which can create delayed blue toning: he uses hot distilled water to rinse his MS-70 treated coins as hot water greatly shortens the rinse time Just use common sense, experiment, and have fun.
The photographs show the approach used by one of the authors.
OF ETHICS, CUSTODIAL RESPONSIBILITY, TPGs and NCS
“JUST SAY ‘NO’ TO DIPPING” - Some purists howl at the mere thought of tampering with a coin, but these people are rarely modern coin enthusiasts. Tarnish on older silver coins often has a deeper foothold on the coin and its removal can leave a coin luster-less, dull and “cleaned” looking, even though the surface will appear bright to casual inspection.
Purists argue correctly that old coins are what they are, and tampering with them is a violation of trust, a violation of our responsibility to pass along historic coins without adulteration.
Coin entrepreneurs, on the other hand, can make a living by buying heavily toned classic coins and cleaning them to a “BLAZING WHITE!!!” (if you’re self possessed enough to linger in a men’s room at a coin show for an hour, you will probably see a dealer or two hurriedly clean some coins right then and there in quest of a significant profit upon re-sale).
Most collectors in the early stages of collecting (and some for the duration) prefer white coins: nothing wrong with such a personal preference but once a classic coin has been stripped of its tarnish, it has often been stripped of its history, its essence, and sometimes of a significant amount of its original surface metal including some or all the die-flow lines that create lustrous cart-wheeling, the single most important factor that brings a coin to life and gives it eye-appeal.
DIPPING IKES - Cleaning Ikes and other moderns is a different story. The ugly dirty toning that is so common on Ikes of all grades is easily and safely dipped off, and if done with the minimal amount of chemical, the luster of the underlying surfaces is not impaired. A properly rinsed and subsequently protected Ike will regain and retain its smashing new-coin look.
A dipped Ike with fresh metal surfaces will tone more quickly than an original Ike that already has some toning, and since such re-toning is unpredictable and likely to be ugly, protect any dipped coin just as you would protect an original blazing white Ike you got from the middle of a pristine roll. Seal the coin from exposure to moisture and the trace oxidants present in household air by storing it in a flip. Store flips in boxes (and TPG slabs in their boxes) in a small space with inexpensive little boxes of silica gel (these absorb moisture and can be recharged by drying in an oven at 250 degrees for several hours). It is amazing how rapidly an absolutely fresh blazing white Ike removed from a roll will begin to dull if just left out in the open when humidity is high: in a month or two you might not recognize the coin.
We emphasize that moisture is the main enemy of coins in storage. If you store your coins in a safe, be sure to include one or two little boxes of “silica gel”.
“Intercept Shield” products and the like provide additional protection if you live in a place that has more than its share of atmospheric pollution or if you just don’t want to take a chance.
Be aware that early generation fire-proof safes used a lining material that retains moisture to stay wet: the interiors of these safes typically have high humidity and can be a disaster for coin storage.
ETHICS AND REAL WORLD EXAMPLES - There are several situations when it seems more ethical to clean a coin than to leave it alone, especially in the sense that we are custodians of the coins we own. The PVC “green-black grunge” residue mentioned earlier that acetone can remove is a good example. Without removal, this residue will gradually eat into the surface of an afflicted coin and destroy it. An acetone soaking may save the coin.
Another example is the “fogged” (“clouded”) Ike, a condition where the coin develops a dense white fog, typically over the central device on one or both surfaces. By the way, this can occur in holdered Ikes and thus may be due to residual surface contamination that continues to fester even in a holder. The authors are suspicious that inadequate rinsing after dipping may be one cause of fogging. In any event, it seems to be more prevalent in humid climates, seriously!
Fog can sometimes be removed with an acetone soak. Holdered fogged coins obviously would have to be cracked out for treatment: getting them back into a holder at the same grade is always problematic. The best TPG’s stand behind their products and will either clean and re-holder a coin that fogs in their holder or buy it back from you.
An important option for cleaning any coin is NCS, NGC’s professional conservation service and the only such service currently available. They employ a variety of proprietary coin cleaning and dipping techniques: the results can be dramatic but sometimes less than desirable. It is always a gamble to clean a coin, any coin.
For the authors, dipping an Ike made ugly with dirty-looking toning is an act of preservation, an act of kindness, comparable to cleaning a lovely painting that has become cloudy with cumulated dust and dirt. All of us, however, have gradually become more comfortable with “original skin” toned Ikes in their natural state and less drawn to “BLAST WHITE!!!” Ikes.
When considering the purchase of a “BLAST WHITE!!!” Ike remember that it may have been dipped: if dipped and not rinsed properly it is vulnerable to unpredictable re-toning (which can get ugly) or fogging.
If you like blast white Ikes, it is not a bad idea to experiment by purposefully “over-dipping” and multiply dipping some Ikes with no premium value to learn first hand how to avoid similarly treated Ikes.
Will TPGs Holder Cleaned coins?
Top tier TPGs will reject any coin that has had metal physically moved or removed in the cleaning process. This includes whiz lines, “hair-lines” and certainly any “wind-blown” effect and more extreme examples of over-dipped coins. They will holder properly dipped coins. If a given dirty-toned Ike is unusually free of hits and planchet defects, dipping can even increase the chance of a higher grade. PCGS, for example, seems to down-grade Ikes with toning, even pretty toning if that toning could be hiding luster breaks or small hits. (Shady coin doctors will artificially tone coins to try to hide small areas of luster break, hair-lines and small hits, buyer beware.)
DIPPING WILL NOT IMPROVE A LOW GRADE IKE!!
Dipping a low-grade MS Ike makes the hits more obvious and uglier. This can not be over-emphasized. Dipping a circulated Ike will NOT make it look uncirculated. Dipping an Ike will NOT improve its appearance unless it has strong lustrous surfaces and minimal hits under its veil of grunge and tarnish.
Test this yourself on cheap and circulated dirty, grungy and toned AU Ikes before even thinking of dipping a better Ike: you’ll be glad you did.