I usually never say I'm wrong since I think I never am wrong but here is one time I may well be really wrong. GDJMSP keeps saying how Acetone can and does sometimes discolor coins. I keep saying that is impossible or rather improbable. So here is a photo of some coins; All of these coins have gone through some horrible experiences. All were either polished or cleaned or corroded badly. Note the large cent. It was given to me due to massive corrosion so I started with solutions like Acetone, Laquer Thinners, Alcohols and almost anything else that possibly may fix it somewhat. The IHC is worses on the reverse and the corrosion is somewhat less than when I started. Both Nickels at one time were so polished they looked like Chrome. SLQ too was polished but not as bad. All the cents were just corroded, dirty and then cleaned by something. Not long ago I placed all these in a glass jar of Acetone, left it for weeks outside on a picnic table, covered of course. After about one month just sitting there I took all of them out and placed on a kitchen window sill. Not rinsed with anything. Note the actual RED color of the large cent. Appears GDJMSP was correct saying sometimes Acetone could discolor a coin. I've no idea why only that one turned RED but it is really, really RED. Not the Red people say about a Lincoln Cent but a real RED Note the differences in color of the other Cents. All reacted differently to that last Acetone bath for that time. Might be due to all coins being together, or in the Sun, or anything else. Odd that the SLQ appears to be the best condition now. I know it could not have been due to some contamination on the coins since all of these had already gone through a massive attempt to get rid of polishing, cleaning, corroding, etc. So I guess I'm wrong for the first time in my life?
Are there before pics? There are much better methods for using acetone. I would bet all of the coins now have a layer of stuff on the surface.
Possible but not likely. I've been using such chemicals for many, many years. There is nothing on those coins except air. Although they were not rinsed off after the Acetone, the excessive dippings and soakings in different solutions makes it impractical that there is any residue from previous substances.
Unh huh - mind if I roll my eyes too Nobody's always right Carl. The only thing that sets most of us apart from those who think they ARE always right - is we can admit to being wrong
And if you read up on acetone you will find comments that it can react some with copper IF LEFT EXPOSED TO STRONG LIGHT FOR EXTENDED PERIODS. Weeks outside on a picnic table would probably qualify. But there is no reason to do any such thing. I still maintain that when used as a brief cleaning solution to remove organic gunk, the only time I have seen it change the color has been when the copper was already artificially recolored. Sometimes the gunk is also what is causing the color of the coin. Remove the gunk and it looks different.
Sorry I too read that article about the electrolitic possibilities of Copper when exposed to Acetone with some water and in Sun light. And it was supposed to be water and Acetone, not just Acetone. I've tried that numerous times with all types of Copper. All variations of light. All variations of time. I just don't have the same Sun that the person that wrote that did. And weeks exposed to the Sun on a picnic table had no effect on any of these coins. This all happened after that on a kitchen window. Again, none were rinsed with distilled water after the Acetone. All coins could not have had any contaminations since all of these were previously dipped in numerous solutions to remove polishes, dirt, etc. And note only certain coins reacted by turning colors from all this which also indicates certain Copper coins react differently with different solutions and substances.
A significant addition to Carls statement is that the acetone and water were not mixed, the water was in the form of water vapor ( up to 50% as I recall), and the copper was pure foil , and I doubt if it had formed any patina. They also said that acetic acid formation was slow to form. The experiment was done in 2000 and published in 2001, mainly for the copper industry saying that acetone is not a good degreaser substance. Scientists constantly see such claims against established standards and methods, and further experiments don't seem to have occurred, ( I am not completely sure of this as since retirement, I don't have the subscriptions to the journals full paper, just abstracts). Now I have to explain to my "good coins" why they have to be in the dark the rest of their lives! Acetone Jim
Hmmmm - don't suppose it might that old timers knew what they were talking about now do ya ? Probably the oldest advice that can be found regarding the proper storage of coins is this - store them in a cool, dark place. That's it, didn't use to be anything else other than that. And that was decades before the "science" to explain it all even existed.
