Acetone is ok right?

You might try putting one of them in a dish lined with tin foil and pour a cup of boiling water with 2 Tablespoons Baking Soda + 1 Tablespoon Salt on it. The reaction removes sulfates like the black spots on silver and the boiling water helps with the dirt. Worth a try ?

 

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Doug, didn't you say that there's a problem with using acetone on copper?

 

This will ruin the coin.

 

Has anyone used other solvents on coins? Such as Diethyl ether, Dichloromethane, Hexanes, Benzene, Ethanol, ect. Halogen solvents I doubt would be a good idea. However, since I am not brave enough to try it on my coins I can not say for sure. I have played a bit with THF (tetrahyrdofuran) on a few junk silver quarters and didn't see any noticeable damage (I dipped it for a minute then dried it in a 50*C oven overnight).

 

badthad recommends water, acetone, and then xylene (or toluene) in order (but I don't remember which direction) due to the polarity. That would be to remove dirt and PVC plasticizers. It will do nothing for verdigris.

 

So what is used to safely remove verdigris?

 

Acid. Unfortunately, it does more damage than good 99% if the time.

 

So

Safely, I think Thad's Verigone now being replaced with the Verdi-Care are the best chance. However, some levels of verdigris damage is beyond any help.

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Exactly! :smile

 

Yes, if there's copper in the coins, it's probably verdigris.

DO NOT USE ACIDIC FLUIDS SUCH AS LEMON JUICE OR CATSUP! Both will permanantly damage the coin surface resulting in cleaned (and ruined) coin.

 

Only worth trying if you want to completely ruin your coins.

 

I have tried about every solvent known to man. Depending on the problem, most are completely ineffective and may change the patina.

 

It's called the Polarity Ladder: water>acetone>xylene

Verdigris will generally not be removed by following the ladder.

 

I thought that was the direction you usually go, but I could not remember for sure

 

See my sig. :kewl:

 

BadThad, what effect did pyridine have (or other amine solvent if you did try it)? Have you tried peroxides? (i.e 3 to 30% hydrogen peroxide)?

 

Amines are far too harsh on the surfaces. Pyridine stinks to high heaven too! Amines will lighten the surfaces. Peroxide is even worse. Collectors using such solvents will usually end up with a damaged coin.

 

heres an example of what im talking about.......maybe its not PVC?

 

Did you try the polarity ladder on it?