Cleaning coins ( if you must that is)

[Cu Lung]

CLEANING SILVER COINS (please note this is not recommended for older valuable coins as cleaning will decrease value) Article reposted from yahoo.

Silver coins, when newly minted, have a bright silvery-white surface. A chemically active metal, silver tends to tone deep brown to black. Circulated silver coins will often have a dull gray appearance, sometimes with a deep gray or black area. Silver coins acquire a blue, green, or violet oil-like tone through tarnishing that can enhance the appearance and desirability of an old silver coin and should not be cleaned.

Many collectors will not buy silver coins that look as if they have been cleaned. When tarnish becomes dark brown or black, and a coin's design is hard to see, there may be some desirability to cleaning it using non-harsh methods, but never with an abrasive paste or cloth.

Clean dark silver coins with ammonia, vinegar, rubbing alcohol, lemon juice or polish remover with aceton. Allow coins to soak in a container of the liquid until any dirt or encrustation has been dislodged.
Air-dry or pat them dry with a soft, clean cloth. Do not rub or polish. This may scratch the surface of the coin and will remove metal from the coin's surface. Any wear or scratches will decrease the value of your coin!

Note that silver coins can oxidize rapidly, especially in the presence of sulfur, such as is found in paper products. Some oxidized toning can be desirable but black silver coins are not. Only store your coins in proper containers, such as 2-inch by 2-inch sulfur-free envelopes available at coin dealers.
CLEANING COPPER COINS

Copper is among the most chemically active of all coinage metals. When a copper coin is first struck it has a brilliant pale orange surface and turns brown when circulated.

Copper coins tend to look worse after being cleaned and are more easily ruined than gold or silver coins. When absolutely necessary, clean dirty, green crusted, badly corroded copper coins without scrubbing them. Try soaking them in grape oil (or olive oil if grape oil is not available).

Some results can be obtained in one to four days, but don't be afraid to wait several weeks, months, or even a year for desired results. Remember, some of the green patina may be desirable in a copper coin. Although not so much a problem in Colorado, the prudent collector in a humid climate does not collect red copper coins which oxidize badly. Even in Colorado, it is wise to keep a desiccant in proximity to brown copper coins to absorb air moisture. Every six months, check your copper coins and stroke them with a soft camel's hair brush, such as is used on photographic lenses.

Another way to clean copper coins, use a product (available from any good coin supplier) called MS70. Use rubber gloves, this stuff will dry out your skin. It is safe, but if whatever is on the coin is stubborn, the coin can be soaked for days and even weeks in the MS70. You may use a soft toothbrush that will not harm the coins surfaces to remove the dirt in the devices and continue soaking. When you are satisfied with the coin's appearance, neutralize the MS70 from the coin with baking soda and warm running water. Dry the coin thoroughly and then apply a coat of Blue Ribbon coin cleaner and preservative, and let it dry for several days (or as long as it takes). Wipe any excess off with soft cotton balls, and store in safe cardboard 2 x 2's with the clear centers (use the ones that staple shut, not the self stick, that glue dries out and may not be safe). Make sure that the supplier tells you that the 2 x 2's you bought from him are safe. If the coin is somewhat discolored, you can use Dellar's Darkener after the soaking in MS70. Wipe any excess off and let it dry for days, or as long as it takes so that no more can be removed from the coin with a cotton ball. Use this before the Blue Ribbon until the coin is satisfactory to you. The Blue Ribbon is a cleaner also, and may remove some of the darkener, but the end result will be a beautifully clean and conserved coin for your collection.
NICKEL COINS

Nickel coins, when first minted, are dull silver in appearance, not as bright as silver. Circulated nickel coins have a gray appearance. Nickel coins are best cleaned with clean, warm, soapy, distilled water and a soft toothbrush. For stubbornly stained nickel coins, ammonia, diluted 3 to 1 with distilled water, has been used successfully.
STEEL COINS

Steel cents actually rust in the presence of humidity. Although difficult to store properly, "steelies" were made in such large quantities that they are never likely to become rare.

Cleaning Coins Process
If you have decided to clean your coins, clean them the same day they are discovered to prevent corrosion from continuing to build.

A first cleaning step for any coin may be to soak it for a few minutes and wash it in clean, warm, soapy, distilled water in a plastic container, using a mild liquid dishwashing soap and a very soft toothbrush. This may be all that is necessary. To make your soapy solution, use one tablespoon dishwashing liquid soap to a pint of water in your plastic container. Remember that metal containers can cause galvanic action of dissimilar metal alloys and will damage your coins!

Accumulated dirt and grime can usually be safely removed from a coin with the application of petroleum jelly (such as Vaseline) to both sides using a cotton-tipped swab (such as a Q-tip). Carefully remove the residue with clean swabs and finish with a soft, lint-free cloth.

Isopropyl or denatured alcohol is another non-abrasive cleaner that can be used in place of grape or olive oil. Never, however, use baking soda for a cleaning rub; baking soda may make a coin shinier, but will almost always ruin the coin's numismatic value.

A good example of corrosion that should be removed is Polyvinylchloride (PVC), a chemical found in older plastic coin holders that over time leaves a green, adherent, acidic, sticky, slightly scummy, scuzz discoloration on coins. This scuzz can spread so it is best to remove it as soon as possible using an organic solvent. One such organic solvent is acetone. You must adhere strictly to the warnings shown on the container, as a solvent such as acetone (found in nail polish remover) can be dangerous. Organic solvents can be used to remove tape or adhesive residue.

Some archeologists, professional coin dealers, and metal detecting hobbyists have used ultrasonic tanks that use ultrasound waves to agitate the clean, warm, soapy, distilled water in which coins are immersed. Sound waves are more gentle than even a soft toothbrush.

Expensive, specially made, commercial coin cleaning agents are available at coin shops. These cleaners should only be used as a last resort. You should never put gold coins into jewelry cleaner. Neither should you should dip silver coins in silver dip or polish them

After cleaning any coin, rinse it with distilled water, not tap water, which contains minerals that may leave spots on the coin. Some people suggest adding a final rinsing in isopropyl or denatured alcohol.

Dab or pat rinsed coins partially dry with a soft, lint-free cloth, then allow them to air-dry without touching each other on a soft cloth without rubbing, which can cause minute scratches
Good Luck !

[penny pretty]

sounds complicated. I just pour a shot of jack put a few pennies in, drink then spit! pennies dont look so great, but nice buzz!

[Cu Lung]

sounds complicated. I just pour a shot of jack put a few pennies in, drink then spit! pennies dont look so great, but nice buzz!

I believe that method is ideal for mostly any problem.

[dannan14]

sounds complicated. I just pour a shot of jack put a few pennies in, drink then spit! pennies dont look so great, but nice buzz!

I believe that method is ideal for mostly any problem.

Well, an exception could be for teh problems that require superglue. i don't think superglue and Jack mixes well

[Diggin4copper]

Clean dark silver coins with ammonia, vinegar, rubbing alcohol, lemon juice or polish remover with acetone.
Thats quite a cocktail.... Someone will die if they breathe those fumes... Use only one cleaner at a time,, dont mix them

This has been a public service announcement

[tractorman]

A collection of informative articles that some may find of interest.

To Clean or Not
By Mike Thorne, Coins Magazine
April 10, 2008

http://www.numismaster.com/ta/numis/Art ... cleId=4094

More Advice on Coin Cleaning
By Mike Thorne, Coins Magazine
June 02, 2008

http://www.numismaster.com/ta/numis/Art ... cleId=4580

More Advice on Coin Cleaning
By Mike Thorne, Coins Magazine
July 16, 2008

http://www.numismaster.com/ta/numis/Art ... cleId=4941

More on Cleaning
By Mike Thorne, Coins Magazine
August 27, 2008

http://www.numismaster.com/ta/numis/Art ... cleId=5194

This was posted over at BS. Please note that the author is discussing silver coins, AU or better. NOT copper/brass coins!!!

[silverhedgehog]

I have to agree on the use of olive oil as a soaking agent. Last month I put a handfull of Wheats in a jar with olive oil and soaked them for a month. I shook them every time I sat down to sort. In the end I drained them and cleaned them by soaking in Dawn dish detergent and warm water for an hour. It did a good job and the olive oil soaked into the coins to leave some protection behind. Some needed a little toothbrushing to get the gunk off but the results were good. In the end about 50% were in good shape and the others were already damaged anyways with dings and scratches anyways. Now I have 253 ugly Wheats soaking the same way and will not know the results for a few more weeks. The olive oil did not change the color of the coins like the acid in CLR does. I looked at this process only for coins that have a higher than scrap value.

[NiBullionCu]

Here is a link to another great article:

"Coin cleaning secrets of the ancients" by Bob Reis

http://www.anythinganywhere.com/info/clean.htm

[rickygee]

Good advice for coins with numismatic value, but for really grungy copper cents of common date, including wheats, a little Ajax or Comet cleanser and a stiff brush and them babies will glow! No they won't shine, all the scratches will prevent that, but they do have a unique look. Now we're talking coins that are going into the bullion stack, cleaning is just so the grungyness doesn't 'infect' other coins. Yes, I've done a few Wheats.. I've even scrubbed the Queen!

[crazypennyguy]

Clean dark silver coins with ammonia, vinegar, rubbing alcohol, lemon juice or polish remover with acetone.
Thats quite a cocktail.... Someone will die if they breathe those fumes... Use only one cleaner at a time,, dont mix them

This has been a public service announcement

Yeah, but think of what would happen if you can get a buzz off the vapours

[Engineer]

I just tried ammonia on a junk Roosevelt and wasn't very happy with the results. The toning came right off and left the coin a little too shiny. It might be a cure for milk spots though.

My two cents is that acetone or paint thinner seem to work the best for removing grime without messing up the patina of the coin.

[ROC]

Great Info, Thanks!

[Numis Pam]

This thread was just what I needed! Couldn't sleep last night so did some reading on RC and this one was very helpful. Thanks

[68Camaro]

re: Silver

Has no one here used a magnesium plate under water, on coin? It's a popular jewelry and flatware method, as the magnesium has a higher galvanic potential than silver and pulls out the oxygen, sulpher, etc from silver tarnish and (supposedly) leaves the silver behind. I've not tried it on coin yet myself, but I have a piece of it, and it has worked great on silver chains and decorative pieces.

[68Camaro]

re: Silver

Has no one here used a magnesium plate under water, on coin? It's a popular jewelry and flatware method, as the magnesium has a higher galvanic potential than silver and pulls out the oxygen, sulpher, etc from silver tarnish and (supposedly) leaves the silver behind. I've not tried it on coin yet myself, but I have a piece of it, and it has worked great on silver chains and decorative pieces.

Would appear from the below to be not recommended for coin!

It should be noted that the process is not converting the silver back to the original hard, lustrous surface, but into a soft, white powder that can be removed by
rubbing. The sulfide has actually dislocated some silver atoms from the metal surface, and the cleaning treatment will not relocate them, but it will eliminate the unsightly, dark, tarnish.

http://stason.org/TULARC/science-engineering/chemistry/31-16-How-do-I-remove-silver-tarnish.html

[TwoPenniesEarned]

You should never clean coins.

[Dave]

CLR does not work on copper. I use acetic acid, soak them for 2-3 days rinse well with water and they come out looking good.