Does PVC affect nickel coins?
DisneyFan
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MWallace
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Yes.
Edited to add: If you are asking about US Nickels, remember they are 75% copper.
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Sapyx
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Pure nickel coins are more resistant to PVC damage than copper and copper-alloy coins. Many times, when disassembling an old collector's PVC-laced "world coin album" page, the copper/bronze/brass coins are all horribly unsalvageable, but the pure nickel and pure-nickel-plated coins are barely touched.
Note the words I've used above: "more resistant" and "barely touched". They are not immune. The acid that causes PVC damage is sulfuric acid, and sulfuric acid will attack nickel.
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Crypto
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I have seen piles of buffalos covered in years of active PVC so thick you could barely tell they were buffalos only to be treated and come out glowing near gems. If it eats into them it is very, very slow. No pitting and full flashy luster post treatment.
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Sapyx
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@Crypto said:
@PerryHall said:
Wouldn't a quick dip in acetone be quicker, easier, and more thorough? I wouldn't want mineral oil residue left on any of my coins.Meant to say Mineral Spirits which is like acetone. It might be closer in chemical composition to acetone than different But I’m no chemist .
Acetone and mineral oil are quite chemically different; the only similarity is that they are both petroleum-derived, and both are flammable (though acetone somewhat more so).
Acetone is a pure chemical whose molecules have a polar structure, due to the oxygen atom sitting in the middle of the molecule: CH3-CO-CH3.
"Mineral spirits" is not a pure chemical but a complex mixture of various hydrocarbons, not entirely unlike gasoline, ranging from pentanes (5 carbon atoms, like CH3-CH2-CH2-CH2-CH3) up to dodecanes (12 carbon atoms), arranged in various chains and rings. These molecules are mostly non-polar in nature.
While both can work at dissolving the green goo of PVC residue off of coins, there are three properties which make me prefer acetone over something like mineral spirits.
1. Acetone, being polar, is more suitable at removing the phthalates (also polar) that form the main component of the goo. So, it works slightly better, in theory.
2. Acetone evaporates away quite quickly. Mineral spirits (depending on the grade) mostly do likewise but are generally slower, and may contain some compounds that aren't volatile at all. It won't leave solid residue behind, but there may be a thin film of liquid.
3. Acetone is water soluble, mineral spirits are not. So you can't simply wash the waste solvent down the sink with lots of water.The main advantage to using mineral spirits is that plastics are less likely to depolymierise on contact with it, so you don't have to be as paranoid about keeping all plastic objects away while you work on the coins.
If you have mineral spirits on hand, and don't have acetone, and you've got a system with it that works for you, then by all means keep using it.
Waste no more time arguing what a good man should be. Be one.
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Answers
Well that appears to be the definitive answer!
What about Buffaloes that have a slight transparent PVC haze? Can they be conserved so they will receive a CAC?
That really depends on the coin under the film and the plastic it ends up in. Many coins with stickers have been conserved in various ways but of course there is risk. Use mineral spirits and a q-tip going in small circles, change out the q-tips frequently until they stop coming back Green. Dab dry with a soft cloth. That how i was taught at the B&M.
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Yes and horribly.
Wouldn't a quick dip in acetone be quicker, easier, and more thorough? I wouldn't want mineral oil residue left on any of my coins.
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"Paper money eventually returns to its intrinsic value---zero."----Voltaire
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Meant to say Mineral Spirits which is like acetone. It might be closer in chemical composition to acetone than different But I’m no chemist .
11.5$ Southern Dollars, The little “Big Easy” set
Have you ever put a drop of mineral spirits on a piece of clean glass or mirror to see if it leaves any residue once it evaporates?
Worry is the interest you pay on a debt you may not owe.
"Paper money eventually returns to its intrinsic value---zero."----Voltaire
"Everything you say should be true, but not everything true should be said."----Voltaire
No but I have cleaned or witnessed thousands of coins get treated by them. To these eyes MS are like a less fragrant acetone.
I have used a foldable non PVC flip as a holder to dip my Q-tips in while going though coins that hit the counter or going out to grade. Once it evaporated, there was no trace or residue left over the next day inside the flip. I have used acetone too but the OG dealer I learned from used MS for his stock. He has forgotten more than I have ever known so who am I to argue.
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