Trends In Cleaning Coins

I tend to agree with the original poster. Except in extreme cases, I think cleaning is irresponsible. Today's common coins are tomorrows semi-keys. Think of all the beaten up key dates that one wishes could be held responsibly but were messed up some deceptive coin dealer or some kid out having fun. That being said, if you own them do what you will. But, consider the future owners who would love to have that coin with a little grime on it.

I advocate the proper conservation of coins in their current state - by removing harsh chemicals from chosen storage methods and removing grime placed onto a coin through circulation. Either way, if done properly, these contaminants can be removed from a coin without detrimentally harming the surface of the coin itself.

"Cleaning" - or dipping in acid or other harsh chemicals to "improve" the appearance of a coin is dead wrong, as is using buffing tools to remove scratches and other embedded problems in coins.

There is a very distinct difference between the two that can take years of knowledge and experience to discern. Not every coin is a candidate of proper conservation techniques, and not every technique will work for every coin that is a candidate. It takes a matter of long, hard work to know what to do and how to do it properly...not to deceive, but to remove things that cause more problems for coins if left alone.

With that being said, acetone is almost ALWAYS the wrong solution for copper. Like I said, know the right techniques before you chance ruining a collection with wrong techniques.

Are those "right techniques" described somewhere? Or does that remain a trade secret only for those with years of experience? I'm not intending to be abrasive here (parden the pun). I would just like better clarification on what the exact parameters are for determining whether a coin should be cleaned, dipped, conserved or whatever. Verdigris is a legitimate issue and if left untreated can/will continue to deteriorate a coin. I get that but let's be real. How many coins suffer from this? I seldom run across coins in this condition.

On the acetone issue, wow, I don't know what to make of this. I have heard from staunch believers that acetone is the greatest thing since apple pie. Quoted as a solvent that does nothing to the coin but remove moisture with no ill effects. Although I have recently seen images on this forum to the contrary, hence my reluctance to do it myself. I'm not in complete agreement that acetone can have no affect on a coin's color. If it is primarily used for moisture removal, then why not just use some desiccant blocks? I've not heard that it is effective for verdigris removal.

My collection focus is mainly Lincolns. I have cents ranging anywhere from a $1 to upwards of $1k but I'm not sure I would even try dipping my $1 Lincoln into a chemical it was never intended for. I also don't know what the cent will look like in 5, 15, or 30 years from now. Hey, maybe this is a symptom of obsessive compulsive disorder. I also cannot break open proof sets! :)

Johnstac - I wasn't trying to be elusive with my explanation regarding technique, but it would involve a book with many hundreds of pages to describe every possible scenario with every possible solution, and even then it would be a libelous task because someone would inevitably ruin a coin "following the directions" and want to go after the author - which is the primary reason why I don't even attempt to teach people how to conserve coins properly. It does indeed take years of practice and technique to get it right most of the time, and even I screw it up 10% of the time knowing what I do. It's not an exact science, and there is no set rule of technique.

The ONLY set rule is that if you don't know what to do to help the coins, don't do anything to them.

Regarding acetone - it will almost always change the color of any copper coin it is used on, and in many cases it will produce an unnatural sheen if rubbed. I have found it to produce far less than perfect results on most specimens and have found its use to be less than perfect most of the time. I simply do not recommend it for Lincoln cents at all.

johnstac, "cleaning" by coin industry standards doesn't mean the same as it does for other applications. For most things to clean something means to remove dirt and contaminants from the surface. In the Coin World it means to chemically alter the surface by removing the natural toning and/or polishing the coin.

Acetone is completely inert to the metals used for coining, but it does react very harshly against most of your common dirts and oils. This makes it an excellent choice for 'washing' contaminants off of, and thus preserving your coins. What's more it evaporates quickly and completely. Mild soaps are also acceptable.

But coin and jewelry polishes and dips that remove natural tarnish and make the metal shiney render the coin unoriginal, and as such are considered 'problem' coins. And it's especially bad to do to copper coins, because the color of the new shiney surface almost always looks dramatically different than a natural BU red example.

I USED to think this was just not possible. I always thought Acetone had little to no effect on anything metal. So naturally I had to experiment to prove people wrong. Guess I was the one that was wrong. Here are photos of a pile of coins left in Acetone for an extended period of time.



And oddley enough, not all coins are effected equally. For example the Large Cent turned a REAL RED. The Indian Head cent not as much. For some reason the 1919 Lincoln turned real dark. Of course the amount of time for each coin soaked was different so naturally the results differ. The main thing is Acetone does effect Copper coins.

coppercoins: Let me preface this by saying I love your posts and insight and I've learned much from reading your contributions. That being said, I think your position here...




... only adds to the elusiveness. Seems a catch-22. One needs years of practice AND one should not do anything to a coin, unless you know what you are doing. Hard to square that. Maybe one should practice on common coins while trying to perfect a system and technique?