So I've got a 1839 LG Cent with large chunks of patina on the obverse of the coin. Is there any way to remove it at home or with some sort of professional restoration service without damaging the coin or its value? Found it metal detecting.
If you're going to clean a coin, you might as well clean the entire thing. You shouldn't though, in this condition, a coin wouldn't go unnoticed of a cleaning and just hurt its value than what it already is.
Looks like a metal detector find; was it? Let's call in @paddyman98 (I think he MDs around NYC) to see what he thinks. Steve
On January 9 I will be at the Chinese counterfeit talk at the FUN Show which is at 12:30PM. I will be giving out some free CDs of my new book Forgotten Coins which has a chapter on how to detect Chinese counterfeits. The speaker does not know this yet and will announce this freebie at the meeting. So what does this have to do with cleaning copper? - I developed a cleaner for cleaning copper using the technology of the old Coin Care that was banned. See me at FUN on Thursday - most people know who I am at the Foreign section or announce yourself ... I will be there from 10-4PM. I will be bringing some samples also for FREE. John Lorenzo Numismatist United States.
My honest opinion, that one's not worth messing with, it's just too far gone. But, if ya wanna give it a shot you could try a product called Verdi-Care. It's sole purpose is the removal of verdigris, and it works, and no it does not harm the coins. But here's the thing, there's really 2 things in this case. The guy who invented Verdi-Care freely admits that it seldom works very well on advanced or extreme verdigirs. It will remove some of it but rarely if ever all of it. The second thing, I'm not so sure that is verdigris. Given that you found it in the ground, it might be, but usually it has a different look to it than that. I'm not really sure what it might be. Only way to really find out is to experiment a bit. But like I said to start with, I wouldn't bother. 'Course ya could listen to John there in post #5. The man usually knows what he's talking about so if he thinks he's come up with some new product that works - well, maybe he has.
I have a problem with the word patina on this example. I'm just asking. When I hear or see patina, I'm thinking something that adds a natural quality, ageing and possible value.
With ancients especially the word patina is often used to describe the thick, hard, cased on verdigris that has been there for centuries. Been that way for far longer than anyone has been alive. So some folks use the word in a similar manner, even with far more modern coins. I assumed the OP was doing that in this case. But he'll have to speak for himself.
What you have are corrosion spots, and there is not much you can do with them. In some cases you can push the stuff off with a toothpick, but that's before the bad stuff as "set" into the surface. Once it grabs on to the metal, that's it. You can either scrape it off, which leaves a mark or put up with it.
