I have been quite busy so I have been posting less frequently (or more frequently if you go by threads created rather than replies to other threads) but I had to share this large cent I got at the NWCC show in March. There was a bucket of type coins for eight bucks each, they were problem coins I'm assuming since this is by far the cheapest large cent I've found. Anyway, this has some sort of gunk or corrosion on it, and considering it's likely already damaged (note the scratches, pits, and dings) I figured it wouldn't be a bad idea to get it off somehow. The gray stuff feels kind of like a film, I don't know exactly. The black stuff was removed a little by way of me scratching it with my thumb fingernail, so I don't think any of it is hard corrosion. I hear a soak in acetone is quite frequently suggested, and distilled water for ancients. I've also heard of a mysterious verdigris, is it specifically for cleaning green corrosion off of cents such as this one? I know it's typically considered bad practice to clean modern coins, but again I don't really care considering how it's already damaged and by the looks of it, been harshly cleaned before. Here's the pic, and thanks for any advice!
Since I'm here, I might as well post my two other US coins that I've acquired from the show! These were also eight dollars apiece. My little brother really liked the world coins, he could get five for a dollar. We also each got a Canada dollar, modern ones just for fun. We each left with a little bag of world coins/tokens, and I with some US coins. I think it's safe to say he had fun!
That's a quarter, minted in 1876. I have no idea the mint mark, that's been rubbed off. It's the most circulated coin I own, pretty close to being a slug tbh.
I wondered if it might be a twenty-cent piece, but even in that state I doubt many dealers would let one of those go for $8.
Start with an over night soak in acetone. Then roll a qtip soaked with acetone across the surfaces changing out the qtips as they get dirty. After the qtips stay clean, examine the surfaces. If more gunk is still present re-soak and re-roll the coin. When all the gunk is off use verti-care (not "mysterious verdigris") following the directions. Verti-care can be purchased from Wizard Coin Supply. Note; Your coin seems to have an excessive build up of gunk, tarnish, and verdigris. Complete removal may not be possible or may leave the coin with an un-natural or un-even surface color. Knowing when to stop is a very important step in the conservation of a coin. Like you stated this coin is already damaged making it a good practice coin but an even better practice coin would be a low/no value LWC/LMC with same or similar level of buildup. Please keep us posted with pictures of your progress and of course any further questions. Happy coin conserving, Richard
As mentioned above, I would start with a 24 hour soak in pure acetone, and then the Q-tip® roll and see how that works.
As above, soak in acetone overnight and then roll over the surface with Q-tips, replacing them frequently as they pick up dirt and gunk. You describe the surfaces as hazy which is a good sign if you are conserving with acetone. A quick run down on acetone: Get 100% pure acetone which can be found at hardware stores as a paint solvent (I use Klean Strip brand). As far as container a glass jar with a very tight fitting lid works great. Do not use a plastic container as acetone dissolves plastic. When you're done soaking the coin just open the jar and leave it outside, acetone evaporates quickly. https://www.cointalk.com/threads/coin-conservation-thread.385029/ Here's a few copper acetone before-and-afters from my experience.
Different series of events here... I would first put it in some boiling hot water and let it sit overnight. Change the water for hot water from the tap and see if any of the gunk could be removed with a toothpick or even a soft toothbrush. Dry it thoroughly and then do the overnight acetone soak in a covered glass container. Let us see what it ends up like.
Pretty sure you'd want to use distilled water in coin conservation. Tap water contains impurities which are not exactly great for coins.
Thanks everyone! It's already in the acetone and ready to sit overnight. My mom didn't want me to use a glass jar, so it's in a ceramic bowl on the counter. I'm hoping it doesn't all dissolve, but rules are rules. Here's a picture of it:
I see some early stage, carbonate (white-film). That would easily be removed with VERDI-CARE™. Nonetheless, all conservation projects should begin with deionized or distilled water. Kentucky's "hot water" method works well. On low value, circulated coins, I just go directly to the tap and flush with hot, running water - light rubbing with fingers works fine. The black toning cannot be removed without the surfaces looking "cleaned" IMO. If it is organic based, xylene would be the best solvent choice. I personally never use acetone on coins like this unless I'm intending the dehydrate the coin for storage. In my experience coins with carbonate verdigris get even uglier after dehydration with acetone.
You need to cover the bowl otherwise it will evaporate very quickly. And put it in a well ventilated place. I always have some jam jars with screw on lids handy.
Well, I was off at work while you guys told me to cover it, but to assuage your fears, it is now in a glass jar with enough to cover the coin and the lid screwed on tight. It's a two-piece lid, but it should be fine (I hope). All the acetone from the bowl has dissolved, though it was fairly little (only enough to cover the coin) so I'm not worried.