Acetone Question

anablep

I was just wondering...
I know acetone can be used on silver coins, but what about copper (large cents). Would it damage the coin?
Thanks

cladking

There are some very knowledgeable people here who will tell you that this can ruin a copper
coin so I'd exercise extreme care or avoid it altogether. I've never had a problem with it that
I'm aware of but have only done post 1968 Lincolns generally when they're still pretty new and
rinse them with clean acetone or 91% isopropyl alcohol.

nwcs

Pure acetone shouldn't have an effect on copper coins.

anablep

Hmmm... Thanks, I'd rather err on the side of caution.

BAJJERFAN

Generally yes tho I have heard tales (no pun intended) that acetone caused a purple discoloration of some copper coins. I don't use the stuff myself and would guess that any problems would be due to a poor grade of acetone. Buy the best stuff you can find.

mas3cf

OK, I just did a quick and dirty experiment with reagent grade acetone (>99.8% pure) and 5 pennies in different degrees of RB... it seemed with a mostly red zinc cent (exterior 100% Cu), wiping with acetone actually added a LITTLE BIT of eye appeal, but with bronze (pre 1982) cents and cents with more brown, I observed purple/blue discoloration and/or dulling of the surfaces. Bottom line: no matter how pure your acetone is, DON'T DO IT!! The eye appeal gained in the one case was not nearly enough to justify the risk to a valuable coin.

-matt

nwcs

I've used it on a number of BU cents from 1927 on up and have not seen any discoloration or problems. In fact, it helped remove surface contaminants. Perhaps the only answer is "your results may vary."

1jester

I've not discovered any ill effects from using pure acetone on copper. I've used pure acetone on silver, copper and gold without any discoloration or other problems. I also use a 4-5 jar dipping procedure, where I'll soak the coin in one jar of clean acetone, then transfer it to another jar of clean acetone, then rinse it around in the next jar and so on until the coin is hopefully free of any foreign contaminants.

Be very careful; acetone is extremely flammable.

mas3cf

True, it doesn't seem to have much of a deleterious effect on BU red cents (nor would you expect it to), and 1jester is right... acetone is volatile and flammable, a combination which requires extreme caution!