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 Replies: 12 / Views: 1,286 |
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Pillar of the Community
United States
549 Posts |
I understand that cleaning devalues coins, but I've read in numerous threads that it's acceptable to try several non-abrasive techniques. From what I've read, it's recommended that you try the techniques in this order: freezing/thawing, olive oil, and as a last resort acetone.
My question is whether these techniques not at all damaging to the coin, or just less damaging than using detergents, acids, etc. I honestly don't see how water (freezing/thawing) could ever damage a copper penny, but I'd like to hear some opinions from the experts. Is it ok for me to use water on my coins without any deterioration in value.
I'm asking this question today because I received some old Indian Heads in the mail today and some of them are full liberty, but covered in significant dirt and/or green patina.
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Pillar of the Community
United States
1283 Posts |
quote:
but I've read in numerous threads that it's acceptable to try several non-abrasive techniques.
Cleaning devalues coins, period. Even if it's "gentle" cleaning. Anytime you remove tarnish, or another other natural coloring that's permanent the coin is considered a "problem" coin. The first thing you should try is acetone. Any (surface) contaminants that are NOT chemically embedded into the copper should be successfully removed. Unfortunately there is no miracle cure for problem coins... with one exception. Numismatic Conservation Services aka NCS. They're a division of NGC and they have proprietary, professional methods for fixing problem coins. Many times they can actually take a corroded coin and revert it back to being "original". Basically, the previous corrosion problem is undetectable, and it will NOT show any trace of being cleaned. What was once a problem coin becomes a nice original. |
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Pillar of the Community
 United States
549 Posts |
Thank you. I've read all that before, but I guess what I'm getting at is how soaking a coin in water and freezing/thawing it can harm it? Is this something that should only be done is the coin is already of so little value that the cleaning won't matter? Or is the freezing technique generally considered safe for a coin which is still in very good condition other than some gunk?
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New Member
United States
34 Posts |
"Cleaning devalues coins, period.
Many times they can actually take a corroded coin and revert it back to being "original". Basically, the previous corrosion problem is undetectable, and it will NOT show any trace of being cleaned. What was once a problem coin becomes a nice original."
So then..Cleaning doesn't always devalue coins, period?
I think there are times when cleaning grime or dirt actually helps a coins value. I do agree that this isn't usually the case but I have seen plenty of exceptions.
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Pillar of the Community
United States
7123 Posts |
Hi Paland
I think what UAP is trying to convey is that in most cases it is not recommended that a person with little or no experience attempt to conserve their own coins .
and make no mistake there is a brutal difference between cleaning and conserving a coin .
the devalued part of conservation comes in on the slab that the coin ends up in ,,it is marked as having been conserved with a net grade and that in itself lowers the value ,but at the same time makes the coin market acceptable and in some cases keeps some value in a coin which had little before conservation .
Metalman
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Pillar of the Community
 United States
5953 Posts |
Every once in a while this subject comes up. Sometimes there are heated discussions as a result. Others it just fades away.
Generally if you live by the rule 'never clean coins' you will be ok. As has been pointed out there are acceptable (to some) methods of conserving coins.
But to answer you Question.
I am no chemist and there are a few in this forum who may be able to better answer.
Mixing chemicals and adding or subtracting heat usually equals chemical reaction water is a chemical and there are a lot of things in water than just H2O. Even distilled water may not be pure H2O so there is always a risk or a reaction to the surface of the coin.
Acetone will remove any organic compounds form the coin. but should not harm the metal itself. So if your coin is corroded from PVC damage dipping in Acetone will remove the PVC but the coin will be pitted.
Olive oil generally has a ph of between 4.7 and 5.6 depending on its purity Urine has a PH around 6 Black coffee around 4 so olive oil will react with metal given enough time it may even damage your coin.
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Pillar of the Community
United States
1130 Posts |
Experiment with a worthless coin first, in the same condition as the coin you are trying to clean. But if in doubt, take it to the experts. Once a coin has been improperly cleaned, not even NCS can restore it..
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Pillar of the Community
United States
1283 Posts |
quote:
So then..Cleaning doesn't always devalue coins, period?
I'm sorry. I should have made the exception that if a coin has mud on it and you wash it off it won't devalue the coin. My mistake. |
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Pillar of the Community
United States
549 Posts |
USArmyParatrooper - I know your last response was meant to be sarcastic, but it's actually answered my question. I have a lot of nice coins that are just very dirty and gunky on top and I wanted to clean them off. I'm not talking about "restoring"...just getting rid of the dirt, mud, and gunk that's clearly just surface gunk.
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Pillar of the Community
United States
1984 Posts |
I think Paratrooper's statements are spot on when it comes to 'collector' coins, that is, coins that you expect to have value to collectors after you die or when you decide to sell them. These coins deserve special attention to their condition and conservation.
In the case of coins you collect because you love them and you don't care what anyone else thinks, experiment away. Try different things to achieve the look you want. You've got no one to please except yourself. I find mild soap and water and/or acetone to be good first steps.
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Bedrock of the Community
United States
20753 Posts |
The primary problem with cleaning a coin is the possible removal of some of the original metal of the coin. Many think the dirt, discoloration, greenish substances, etc are just dirt and a little water will get rid of it. The problem is usually the contamination is in reality a substance combined with the metal of the coins. Removal of such contaminations removes some of the metal of the coin. Similar, as noted on the Antique Road show on TV, the removal of anything from an antique could vastly distroy that subject's value. For example removal of a greenish STUFF on an old table could make thousands of dollars difference. The reason is in the old days some pieces of furniture had that put on as a preservative.
With coins if cleaned what appears to be a brand new coin now shows wear and that could well be the loss of material from cleaning.
If you use water also be carefull. For instance tap water could contain anything from an acid to salts to fluorides. If you look at tap water under a microscope it appears as a vast jumgle of garbage and that is put on coins?
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Member
United States
3242 Posts |
Do not clean any coin unless U want to make it worthless or face value.
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New Member
United States
13 Posts |
I have had several coins cleaned by NCS. That is what I would recomend to all.
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Replies: 12 / Views: 1,286 |
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Posted 01/07/2008 10:48 pm
