What is best way to clean and preserve copper coins?

[Carlitosway2]

What is the best way to preserve coins? I use to soak in olive oil if they started to flake before I got them home and it helps sometimes to see dates and detail better but now I just lightly brush in field and left over dirt shows what I think is just as nice details. Any better suggestions?

 

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[Icewing]

Warm soapy water and your wifes or least favorite kids toothbrush.

 

[smokeythecat]

I no longer use oils or even water. You can use a toothpick or get some of those Andre's pencils. They let you get surface stuff off without taking the stuff out of the pits. If you take the coloration out of the pits in the coins, you will probably not be able to see them as well. Aquachigger did a video on this once awhile back which was pretty informative. I never believed mechanical cleaning was better, but it is.

 

[Carlitosway2]

Warm soapy water and your wifes or least favorite kids toothbrush.

I have tried that and it’s a 50-50 split, sometimes they fall apart even more.

 

[Carlitosway2]

I no longer use oils or even water. You can use a toothpick or get some of those Andre's pencils. They let you get surface stuff off without taking the stuff out of the pits. If you take the coloration out of the pits in the coins, you will probably not be able to see them as well. Aquachigger did a video on this once awhile back which was pretty informative. I never believed mechanical cleaning was better, but it is.

I have done a little research on the Andre’s pencil. I do have a very high end dinolite digital microscope that would be helpful but coins and buttons look like the surface of the moon under it.

 

[Kona Koma]

Good job.

 

[Locke]

This guys has a ton of YouTube videos regarding all aspects of detecting and preservation: here’s his tid bit on copper coins.

https://m.youtube.com/watch?v=w7cfVkadI_A

 

[smokeythecat]

My dinolite broke!

 

[Carlitosway2]

This guys has a ton of YouTube videos regarding all aspects of detecting and preservation: here’s his tid bit on copper coins.

https://m.youtube.com/watch?v=w7cfVkadI_A

awesome video thank you. Very few of my coins come up that green color unless I dig in soil with a little more clay in it, they usually come up crusty black like carbon buildup.

 

[smokeythecat]

Some of my 18th century coppers come out simply as worn out discs!

 

[Carlitosway2]

My dinolite broke!

I honestly feel they are quite overrated and priced in my opinion. I found them to be good for going threw a full roll of coins looking for errors quickly but for a a 3rd of the price my Olympus TG 4 is awesome for closeups

 

[smokeythecat]

My Optivisor is my go to at this time. I also have a stable full of quality 10x triplet hand lenses.

 

[Professor of Engineering]

They look great as is! Cleaning old coppers can be tricky...I just clean with a dry "hard" toothbrush and store them away in cases.

Love the Liberty Cap copper!

 

[Carlitosway2]

They look great as is! Cleaning old coppers can be tricky...I just clean with a dry "hard" toothbrush and store them away in cases.

Love the Liberty Cap copper!

I think I will stick with toothbrushes as well. Just Found the Liberty Cap Thanksgiving morning. Thats my oldest large cent but I did find a cut Fugio there as well

 

[xcopperstax]

I'm still in the experimental stage as I don't find these coins very frequently and they are almost always pretty beat up. I've soaked coins in olive oil: I can't say I've seen too much change. I think you need to do it for months to really get results. I've used a stiff brush and a toothpick: sometimes it can improve the coin, other times it completely destroys the detail that is left. The line between dirt, patina and coin is pretty thin sometimes. I recently tried the microwaved peroxide method: It seemed to help on a coin that was probably going to flake and lose all detail. It's pretty amazing even after the peroxide cools down the coin will bubble for days (which is the peroxide working on the dirt) I've also seen large coppers tumbled and details that could barely be seen become a little more pronounced. I am going to go with peroxide and tooth pick for the time being. I'd like to tumble a couple of my coins. It's super frustrating when you have a coin that has detail but has a caked layer of dirt on it. When you scrape the dirt off you are left with less detail. I'm sure you are aware but most of these methods are irreversible. I wish there was one surefire method to get a coin back to it's former glory. Good luck! In your case it looks like those coins still have a lot of detail so that is working in your favor. I'd say just don't get too aggressive trying to get all dirt off if it looks like the details will come with it. Also as a final treatment you can put Renaissance wax on a coin. It will kind of seal it up and stabilize it from what I understand. All that being said I have a long way to go on coin conservation! haha.

 

[namxat]

Imho, these are good as they are. The leaft ones could benefit from removing extra dirt. These look like they have been emerged in sandy soil. Overall, Long Island seems to have very favourable soild conditions.


Smokeythecat, same with me. I dont think its soil condition. To try out I cleande some of those "to death" until the red cooper/bronze came out. Nothing, they circulated until and after they were discs. It seems that my my area until say 1820s a smooth copper disk was as good legal tender as a recognizable coin.

Greets Namxat

 

[dfallis1]

I wont clean coppers with any kind of liquid, even water. It can cause more damage and removing all the dirt usually shows less detail. When you dig a copper instantly remove dirt before it dries. Using a light toothpick or andreas pencils to reveal details at home. I like to leave some dirt in the pit areas to bring out the detail. If put under water, good chance it will look like a toasted disc. Instead of olive oil, try using Renaissance wax. Protects, Preserves, and brings out great detail. I use it on everything, buckles, cannon balls, US and CS plates, coins, the list goes on.

 

[Ammoman]

I wont clean coppers with any kind of liquid, even water. It can cause more damage and removing all the dirt usually shows less detail. When you dig a copper instantly remove dirt before it dries. Using a light toothpick or andreas pencils to reveal details at home. I like to leave some dirt in the pit areas to bring out the detail. If put under water, good chance it will look like a toasted disc. Instead of olive oil, try using Renaissance wax. Protects, Preserves, and brings out great detail. I use it on everything, buckles, cannon balls, US and CS plates, coins, the list goes on.

Spot on!

For those who don't believe, practice on old worthless wheat pennies. In some cases water does not affect the coin but in other cases it destroys all the detail. Do you really want to take a chance on a 1914D or other key date copper? I have taken water to some very pretty green patina pennies only to have the patina flake off and destroy everything about the coin. Lucky for me i have not found any coppers really worth anything.
Good luck.

 

[The Rebel]

After I clean mine up I coat them with Ren Wax. [FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]https://en.wikipedia.org/wiki/Renaissance_Wax[/FONT]

 

[huntsman53]

Extra Virgin Olive Oil can help loosen encrustations, dirt and grime on Copper coins and at the same time, it stabilizes the metal from further degradation. Anything loosened can be removed with a green Rose Thorn with no damage to the coin. The Cons are that it takes weeks and sometimes months soaking in the Olive Oil to loosen some of the encrustations and it tends to darken the coins even further. The Pros, once cleaned and lightly rinsed with water and patted dry with a soft towel, making sure to leave a little bit of the Olive Oil on the coin, they can usually be submitted for authentication and grading with no problems unless there is damage on the coin.

Mineral Oil can also help loosen encrustations, dirt and grime on Copper coins and also at the same time, it stabilizes the metal from further degradation. The same can be done in cleaning as above and Mineral Oil in most cases, will not change the color of the coin. As far as I know, there are no Cons in using Mineral Oil. Just follow the instructions above as in using Olive Oil and even if you only want to preserve the coin from further degradation (i.e. flaking, cracking, acidic corrosion, etc.), then you have done the job and can place the coin in a protective holder to keep or sell, whichever you choose.