A while back I cleaned some very inexpensive silver and copper coins. I did this because I created a reference set to help me learn how to detect cleaned coins. I intentionally damaged a few to see what extreme cleaning can do to a coin. Those coins are beyond restoration. However, the others were only lightly cleaned using different methods. Is it possible to restore the natural light "battleship grey" tone that origional circulated silver coins exhibit or the chocolate brown to copper coins?
Very good post !!! A while back, I bought a collection of Lincolns, several 09-40 sets. A cpl of the sets had cleaned coins in them. The buffed polished coins are goners, but I am able to bring some color back to the dipped coins by sitting them in an envelope on a window ledge ( Arizona window ledge !! ) after a month or so, or Dellers darkener. Of course, I list them as cleaned coins. Have not messed with silver. I have a cpl rolls of AU mercs and will br parting them out soon, I plan on playing around with some dipped BU Roosy's just to see what happenes. I look forward to hearing from others on this most excellent subject. I agree it is an excellent way to learn.
If a coin isn't already damaged, don't clean it (I consider cleaning damaging.) And now we get to the exceptions. EXCEPTION #1: If it is surface debris that is not part of the coin nor coin metal byproduct (oxidation), removal of the crud is acceptable (think conserving vs. cleaning.) I'm talking dirt, encrustations, etc. I'm NOT talking about altering the coin's surfaces beyond what's already occurred. It's just that you better know what you're doing. EXCEPTION #2: Particularly valuable coins that are so oxidized/corroded that cleaning can only make it better. Definitely get it cleaned and by a conservator. Otherwise I know of no way of cleaning a coin that is not detectable. It appears that a very old, very light cleaning with natural retoning is acceptable (and expected.) Apparently many 19th century and older coins had been cleaned at one time. If it wasn't harshly done, it is often ignored. When a coin is abraded or dipped, even lightly, the metal flow lines from the original strike are altered resulting in detectable changes. Could I see the changes? Nope. Not if well and lightly done. But the pros can.
See Oct 8th Coin World. There's an article by Eric von Klinger entitled "No such thing as 'uncleaning' coins" because any kind of abrasive cleaning actually removes metal from the coin. von Klinger says that the "battleship grey" tone is due to metal flow lines from die striking which can't be reproduced if they are disturbed. Cleaned coins can be retoned, but the surface cannot be restored.
You could restore it well enough to fool the untrained eye. But you could never fool the trained eye.
My intent of restoring is not to defraud. I want to learn about detecting attempts to restore coins just like I learned, by means of a self made reference set, about detecting cleaned coins. As you said "You could restore it well enough to fool the untrained eye", well right now my eye is untrained with respect to restore attempts. Lets face it, I'm sure every major grading service has seen every type of attempt to restore a coin. The key word is "seen". By attempting to restore my cleaned coins I can hopefully see the same. So that's why I posted the question.
The best way I've come across to restore cleaned coins to an "uncleaned" state is to carry them around in your pocket with some other coins for a few months. A cleaned XF coins will wear down to an uncleaned VF over time. I'm not sure this will be detected even by a professional since the wear is removing a small layer of metal that was damaged by the original cleaning. Coins are manufactured to endure this sort of wear and if you believe an uncleaned VF coin is better to own than a cleaned XF, yoiu might want to give this a try.
I wouldn't ever want to defraud a buyer. But there are two types coins I have bought to keep, not sell, that I would like to "fix." These are (1) silver coins that are solid black with tarnish and (2) silver coins that have been polished and are bright white when they shouldn't be. These coins are near impossible to see the detail - and the detail is what I want to see. So I would like to add some dirt or whatever to the white ones and brighten the "high points" on the black ones. Any ideas?
I leaned some old wheat pennies I found with vinegar and salt to get off some heavy crusted sand it did work but turned the pennies pinkish color . They were in really bad shape but just wanted to see the dates bad idea huh ?
@Robert Delk. Welcome to Coin Talk. This thread is from 2007 with the last post in 2019. You would get more replies if you started a new thread. One of the unwritten rules is "never clean a coin". If your coins were in such bad shape that you couldn't even see the date then I guess you had no other choice. If you do start a new thread, please include a few photos of the coins.
