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 Replies: 14 / Views: 1,637 |
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Valued Member
United States
96 Posts |
Hi everyone, I am new here and looking forward to having lots of new friends and learning new things. I have not researched this topic here but have done much reading on the subject with many varying opinions. Some people call it cleaning and detrimental (depending on the method used buff, dip, bathe, etc., while others call it preservation.
My question is this. I have a great Braided hair large cent (common variety) which is AU 55+ in condition, however, the reverse has a buildup of that cruddy green copper tarnish. Does anyone have an opinion or know of a safe way to clean and preserve this coin?
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Bedrock of the Community
United States
14454 Posts |
I have heard of people sticking copper coins in a potato and also heard of using virgin olive oil to get rid of the "green death" that builds up on copper coins. I have never used either of these methods but I am sure someone who has will chime in with their results
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Valued Member
United States
178 Posts |
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Bedrock of the Community
United States
12437 Posts |
Soak it in mineral oil, but be warned- depending on the extent of the corrosion, the damage may have already been done and there could be pitting and discoloration underneath the meanie greenies  |
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Valued Member
 United States
96 Posts |
J-easy, I will post some pics today...and yes most certainly I am concerned of what is underneath the 'green death'..but at this point it is a coin with au details and worth nothing...I've also heard ammonia or vinegar can work (both are extremely low acidity levels) supposed to use vinegar first and this can take DAYS in a jar, any thoughts
Edited by fasteddie
04/09/2008 11:09 am
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Forum Mom
 United States
5877 Posts |
If the coin is a better date, you may want to consider sending it to NCS to have it conserved. They do a great job from what I've seen. I have never sent anything to them, but they are definitely the most reliable for conservation. http://www.ncscoin.com/ |
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Pillar of the Community
United States
5318 Posts |
I would stay away from using any chemical that reacts to copper, such as even weak acids. It doesn't take much to affect copper, as even fingerprints will etch a coin. These chemicals are indiscriminate--they may remove corrosion, but will just as easily remove surface metal from the coin. If the coin has value, I would agree with Susanlynn--send it to NCS.
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Bedrock of the Community
United States
17884 Posts |
quote:
.I've also heard ammonia or vinegar can work (both are extremely low acidity levels) supposed to use vinegar first and this can take DAYS in a jar, any thoughts?
Yes I have some thoughts, DON'T!. Especially the vinegar. Vinegar is a 5% acetic acid solution. Acetic acid reacts readily with copper to form copper acetate which is water soluable. So it will rapidly give you a stripped pink copper coin. Edited by Conder101
04/11/2008 4:09 pm
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Pillar of the Community
United States
527 Posts |
I have tried both vinegar, and ammonia on copper coins, and I would not advise either for your coin. I use them on really bad looking, newer coins that I find metal detecting. They work very fast, but even seconds too long will ruin the coin. If ammonia is not removed thoroughly, it can actually cause the "green death" you are trying to remove. The safest thing to use on copper is mineral oil. It is a slow process, taking up to weeks, but the preservation of your coin is the most important thing to remember. Check out this previous topic, it was very helpful. Coppercoins, as his name implies, is an expert with coppers, I would trust his judgement above all others. https://goccf.com/t/25114 |
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Pillar of the Community
United States
914 Posts |
As far as green death on large cents, I have tried absolutely everything I could think of. Stay completely away from vinegar and any other acid.
I'd start with Xylene and see what you can get off first.
Unfortunately, my only other suggestion after that is the very controversial electrolysis.
You'll definitely have pitting once it's done, but at least you've saved the coin.
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Valued Member
United States
206 Posts |
I have a few rolls of comon date, duplicate wheaties.
I'm going to try some of Coppercoins' methods on bringing back the luster.
I'll let you know the results.
Should make for a good Saturday afternoon
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Valued Member
United States
328 Posts |
Vinegar and ammonia have low acidity? Vinegar is 2.4, and ammonia is... ummm... well, nobody knows. I wouldn't toss my coins into ammonium, though.  Mineral oil should do the trick, but as NGiles said, it can take a month or two. |
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Bedrock of the Community
United States
17884 Posts |
quote:
and ammonia is... ummm... well, nobody knows.
Ammonia is such a "low acid" that it's actually a base. And bases can be corrosive as well. |
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Valued Member
United States
96 Posts |
Well the FOLLOWING DOES NOT work on 100% copper, BUT I have (first I tested it (first with valueless War Nickels that have silver and copper) and vinegar works great at removing that green tarnish that they (silver War Nickels)commonly get and it does not add or deter luster. If the coin had no luster it will still have no luster and same for if it had nice luster, it still will, just the green stuff will be gone. As well this method will take from hours to days. Even after examination of the coin through a 10X loupe there was absolutely no pitting Eddie Edited by fasteddie
04/13/2008 08:58 am
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Pillar of the Community
United States
860 Posts |
Hello to all,
Just joined the forums, but have been in coins for about 30 years. As everyone says, don't try to clean important copper based coins with any acidic or alkaline solution because if it strong enough to react with the copper salts, it is also strong enough to react with the unaffected copper area, and will usually produce a "false" color, and recoloring products won't fool many.
Oil doesn't react chemically with the verdigris, but can loosen it. A soft camel hair brush can help to gently remove if it is going to go quietly. Generally it doesn't. Don't try to fix unc or high grade expensive coins~ as said above,send to conservator. Distinguish between PVC green gunk and copper salts.
Acetone works as well as anything for the gunk. Oil is Ok to try for the other, but I have had limited luck with it.
Jim
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Replies: 14 / Views: 1,637 |
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Posted 04/09/2008 04:35 am
