Here are a couple of older threads concerning this subject - https://www.cointalk.com/threads/sonic-cleaners.79908/#post-744973 https://www.cointalk.com/threads/cleaning-and-cleaning.137333/#post-1026121
Sonic cleaning is an excellent cleaning method...for my rifle and pistol brass! Leave the coins away from it.
I'm still meaning to run a set of experiments with low-value cruddy Lincolns and my ultrasonic cleaner. I hate to have a tool and not use it. Then again, I have a Dremel, and I don't use it on my coins. I'm pretty sure that if I load the cleaner with distilled water, put some coins in its metal basket, and drop them in, the metal basket will chew them up. But what if I use a soft nylon net? What if I hold the coins by the edge with soft forceps, or for that matter, with my fingers?
You're on the right track. Minimize the parts of the coin which are not subject to the cavitation action; best to hold it solely by the rim. Wouldn't use fingers, though. Keep in mind, what this does is essentially hit the coin with small explosions of supersonic bubbles; at a micro level it's a pretty violent process and in the worst case you can actually "dent" the coin. However, it's useful for really crudded-up examples.
I'm going to read the old threads to learn some new things. THANKS @paddyman98 for posting them. Ultrasonic cleaners do wonders if used correctly by professionals. Don't you think any of the conservation services, jewelers, etc. around the world use them? If you don't know what you are doing, don't play with them until you learn how by practice. There are many solutions that are used, and DON'T LET ANYTHING "hard" touch your coin SO THROW AWAY THE BASKETS! One final tip: Make sure to manually agitate the coin while it is being treated or you risk the chance of a tiny bubble boring a hole into your coin!
Why is it we're always willing to ask questions and discuss methods, yet so rarely discuss how to choose the right coin for that method?
I would like some of you veterans to do that. I don't clean coins -- period -- because I get the impression that the risks far outweigh the benefits with practically every method I have read about.
That's the most fundamental truth which will ever be posted about cleaning coins. No two problems are the same, no two "correct" solutions are the same, and the appropriate solution for this coin will destroy that one. It takes longer to learn which process is appropriate for the problem than to learn the process itself. Hardest of all, apparently, is to learn when to leave well enough alone.
I liked your excellent answer in another post! However, you can (properly) clean just about anything in them. I do all the jewelry for the ladies in the office and the gold chains for the men when they go back to their countries for vacation. Oh, and coins too.
Is there anything on the planet known to be soft enough (solid not a liquid/gas) to rub a coin with and have it be NOT detrimental to the minty luster?
Yes. Coins are very hardy. On occasion (with my personal coins) I will wipe debris from them with my shirt with no effect visible under a stereo scope. Mint luster is in the metal so plastic, cloth, wood, etc. should not hurt or impair it UNLESS YOU TRY. Now you may cause hairlines but again, not enough to impair the original mint luster.
Proofs aside, obviously, there are many things capable of rubbing (for instance) a nice lustrous Morgan without necessarily scratching the surfaces. The trouble is, you're only doing it because there's stuff on the surface you wish to remove, and rubbing that stuff around is certain to scratch the coin.
There are processes used by experienced "conservators" that generally can amplify the luster when properly applied to an object with minimal surface accumulation/alteration. I believe that inexperienced novices may realize undesirable results when applying same to advanced effects. I found that the general results are determined by knowledge of when/what to use for conservation, in a timely manner. Your general observation is believed to be correct, maybe short of vacuum vapor deposition/honing. JMHO
I had no idea that bubbles could dent a coin or punch a hole through one. A friend of mine has a sonic cleaner and I was thinking of letting him use it on some environmentally corroded coins I have to see if it would show a date.
