Cleaning surface grime - Yes? No?

MDavid

Hi again!

I personally don't believe that an amateur should attempt to 'shine' up an unprotected coin, because I don't feel that there is anything that does not act as a solvent or, worse, as an abrasive agent.

But there is one coin material that is extraordinarily vexing to me: copper. My God; it sometime seems to me that you only have to look at it for it to start to darken to the point of illegibility... (kidding, of course...).

However, a few years ago I read that a way to clean soil off of coins w/o rubbing, is to submerge them in olive oil and let them sit. And, further, that if you continually change the oil and let them sit for some months, that the surface grime will fall away. I wouldn't expect them to shine, of course.

I never thought I'd have the patience to do something like this; but, now, I feel that since it's been a few years since I read this, I probably should have tried it out...!

Anyway, I don't imagine that any of you would ever consider trying to 'clean' a coin; but, has anyone read up on all the do's and don'ts of this? Any legends? Tragic, or humorous?

MDavid

Sn3nut

I tried a simple cleaning experiment a few years back using my wife’s ultrasonic jewelry cleaner. It has a dual-bowl arrangement with one for the cleaning liquid and the other for the rinse liquid. The unit comes with a perforated basket in which you place the items to be cleaned, and a two-speed selector switch (couldn’t tell any difference between the two setting in cleaning efficiency.)

I diluted the concentrated cleaning solution that was packaged with the unit with distilled water, per the instructions for gold/silver jewelry. I placed a variety of relatively inexpensive coins in the basket and let it run for about five minutes. After cycling the basket to the rinse solution (distilled water), I removed the coins and rinsed them once again with alcohol, then patted them dry with a paper towel.

All of the coins I tried this technique with came out looking a whole lot better with all of the surface grime removed compared to when they first went in to the cleaning solution.. I sent a few of them (MS Morgans, PR Frankies and PR Silver Ikes) in to PCGS for slabbing and all came back in slabs – no BBs for cleaning.

The funny thing I noticed that was if I tried the same technique on nickels or quarters, they came out of the final rinse with a redish-pink and/or bluish-purple tint to them. Since I am not a fan of toned or colorful coins, I gave them away raw. I wish now I would have kept those purple Jeffs – some people now pay good money for them!

laurentyvan

if I tried the same technique on nickels or quarters, they came out of the final rinse with a redish-pink and/or bluish-purple tint

I have come to recognize that reddish-pink hue on silver coins; it's usually very faint and doesn't look like toning but is almost always an indicator of some kind of "non-abrasive" cleaning. I like colorfully toned (NT natch) coins but not the hue we're describing here.

A lot of surface dirt is easily removed with acetone and the rolling of a q tip across the surface of the coin.

clackamas

With copper, you are fairly safe with Acetone or mineral oil but nearly every other chemical cleaner will react with the copper so you simply can't use them. I have been trying to find a way to remove, what I think is rubber, from the counting machines used by the mint. Many Lincolns from the late 50's to 60's come Bu with a large white streak, I presume from the counters. If I could just figure a way to remove this I would be elated.

MDavid

Does anyone remember those TV ads for that (I think it was) aluminum sheet that you would submerge in boiling water with Washing Soda (*not* Baking Soda and *not* Baking Powder) that was supposed to shine up silver?

Any thoughts on how effective / safe it would be to attempt to clean up coins using this method? Nickel? Copper? Silver?

If it only reacts with surface grime, then I suppose it might be ok; but if it works like tooth polishers, i.e., actually strips away the top layer of the material that is being polished, then it wouldn't be ok...

TIA! :-)

beartracks42

Get yourself a bottle of MS70 and give it a try. I have had good success cleaning dirt and stuff from coins with it. Rinse with tap water and then distilled water and Alcohol, followed by drying with a soft towel. I have used MS70 as a dip and as a treatment on a Q-tip rolling it over the surface of a coin. It does a good job. It will also remove haze from modern proof coins.

MDavid

Hi Gary!

Thanks for the info! Where does one get some MS70?

How does it do on pennies?

TIA! :-)

beartracks42

I order most of my supplies from www.brent-krueger.com. As for cents, I have not used it myself, but have read several threads from other member and they did not recommend using it. Some folks have recommended other products to remove dirt/grime from copper, such as Goo Gone, etc. Maybe you could do a search on cleaning and read some of them.

Gary