How to clean lots of coins at the same time?

Question

I work for a charity and we have received lots of coins gathered from the bottom of a moat. The coins are quite dirty caked in mud, duck mess and moss. Does anyone know of a way to clean them all in one go, rather than cleaning them one at a time?

Answer 1

put them in some coke, the acid will work wonders

Answer 2

cillet bang?

Answer 3

CLEANING SILVER COINS

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 !

Answer 4

Put them in a cheese-cloth bag and run them through a automatic dishwasher cycle or two. The detergent will do a good job on the coins.

Astrobuf

Answer 5

Definitely go for coca cola.

Answer 6

Put them in a bucket of coke.

Answer 7

old washing machine on 40 wash with tablet! or cement mixer.

try cilit bang or the old fashioned trick of a bucket of washing soda then place crumpled aluminium foil at the bottom then load the coins in and move them round it will remove tarnish but not mud and moss (you need physical movement for that)

Answer 8

vinegar is the best old fashioned way!!!!!! works brill just leave them to soak for a few hour

Answer 9

throw them in the washine machine in a sock .................

Answer 10

A ride in a cement mixer usually does wonders. They'll be far too heavy for washing machines.

Answer 11

Im surprised at you, not only are going in for money laundering you have the cheek to ask how it should be done !

Seriously just put them in a bucket of hot water with some washing powder and swirl them around, leave to soak for half an hour and they will be fine.

Answer 12

I'd go for the coca-cola (the really cheap stuff) as well. It's also good for cleaning toilets as well. It makes you wonder what it does to your 'innards'!

Answer 13

I was going to pipe in with "Cillit Bang", but glittergirl has beaten me to that one.

Or, just could just stick them in a bucket with some soapy water and give them a stir...

Answer 14

If they are just ordinary coins, then any of the above answers should work well (any acid should clean them up), but if any of the coins are old or rare, then it is best not to clean them at all or else leave them for an expert to clean up.

As you work for a charity and have a lot of these coins, it is just as well to check first to avoid destroying a coin worth a lot more dirty than cleaned up.

Good luck with your work :-)

Answer 15

spread them out on asphalt and hose them off

Answer 16

Apparently cola works really well (you may have to quickly wash coins in warm water first to get rid of mud... then soak them in some cola)....

Although... quite by accident... I found something that brings coins up like new!  Rose wine!  No joke... I'd left a little in a glass one evening and somehow a small copper coin had fallen into it, and the next morning when I was clearing up, I spotted the coin.  When I lifted it out... the bit that was soaking in the wine was a sparkling copper colour (as it should be) and the bit that wasn't in the wine was it's usual dirty dull colour.  Mad huh?  

Could be costly to use wine though!!

Answer 17

A really easy way is to empty a bottle of vinigar into a shallow bowl - add some salt....pour in the coins....Leave for an hour or so....

Rinse off the coins in clean water....hey presto - shiny sparkling coins - good as new!

Answer 18

But them in some kind of bleach or hardcore cleaning liquid

Answer 19

This is best left for experts to do - using inapproprate chemicals can do more damage to the coins. Old coins are best left in their original state or just wash the mud off with water . I suggest you contact your local museum for advice. .

Answer 20

put them in  a big bowl and pour vinegar over them, it will clean them and make them shiny!!!