Cleaning old copper cents
GOLDSAINT
Posts: 2,148 ✭
To start this thread I would first like to thank all of you for all the valuable intell. I have received over the last few months here. Being a member here has been a great privilege for me and your thoughts and ideas have helped my collecting abilities more than you will know. That being said I feel obligated to pass on what ever humble information that might help some of you.
As a long time Bronze art collector I learned a few years ago that there is a bacterium that eats away at bronze and copper items once they reach a certain stage. If this disease is not stopped it continues forward, although at a slow pace, until the metal is eaten away and falls into crumbs. You may recall a few days ago I, or rather my wife, posted a 1796 large cent that had been very corroded. Your advice, which was correct, was that this coin would not be slabbed by NGC or PCGS. Since this is a very hard to come by coin, and I wish to do what I could to save the coin from further deterioration,and clean the PVC off, I dug out my notes on protecting Chinese bronzes and found that there were chemicals that would stop this process. As it happens that combination of chemicals can be bought over the counter from most hardware stores. Below you will see the before and after pictures of this coin and what affect this process had in stopping and killing the corrosion as well as lightly cleaning some of the old build up off.
What I did was to pour a small amount of the chemical on the coin and rub lightly with my figures over the sink. Once the coin was where I liked the color and the green corroded holes seemed dead, I washed the coin in vinegar to stop any more reaction and then in water and towel dried. The over the counter chemical is OSPHO, which was originally made for use by welders as a rust inhibitor. If you wish to experiment with this please do so at your own risk, and I would advise you not to do this with ANY rare coins that you know may be slab candidates. If you have some pretty worthless large cents that are not worth much money this may clean them up some. Please add to this post if you have good luck, and don’t post if you have bad luck, Ha Ha.
As a long time Bronze art collector I learned a few years ago that there is a bacterium that eats away at bronze and copper items once they reach a certain stage. If this disease is not stopped it continues forward, although at a slow pace, until the metal is eaten away and falls into crumbs. You may recall a few days ago I, or rather my wife, posted a 1796 large cent that had been very corroded. Your advice, which was correct, was that this coin would not be slabbed by NGC or PCGS. Since this is a very hard to come by coin, and I wish to do what I could to save the coin from further deterioration,and clean the PVC off, I dug out my notes on protecting Chinese bronzes and found that there were chemicals that would stop this process. As it happens that combination of chemicals can be bought over the counter from most hardware stores. Below you will see the before and after pictures of this coin and what affect this process had in stopping and killing the corrosion as well as lightly cleaning some of the old build up off.
What I did was to pour a small amount of the chemical on the coin and rub lightly with my figures over the sink. Once the coin was where I liked the color and the green corroded holes seemed dead, I washed the coin in vinegar to stop any more reaction and then in water and towel dried. The over the counter chemical is OSPHO, which was originally made for use by welders as a rust inhibitor. If you wish to experiment with this please do so at your own risk, and I would advise you not to do this with ANY rare coins that you know may be slab candidates. If you have some pretty worthless large cents that are not worth much money this may clean them up some. Please add to this post if you have good luck, and don’t post if you have bad luck, Ha Ha.
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Comments
Chris
My Collection of Old Holders
Never a slave to one plastic brand will I ever be.
Liberty: Parent of Science & Industry
As a long time Lincoln collector I can appreciate this info.I whole heartily agree with the conservation of your coin or any coin for that matter.Yours especially has historic value.The number of surviving specimens are few and far between.Since it is for your collection and not resale as an uncleaned coin,I say
Registry 1909-1958 Proof Lincolns