Removing PVC damage from some coins

Very nice conservations! CONGRATS I love seeing results.

You're a great customer - followed directions and did everything right!

PVC should always be first addressed using acetone. The polymer-based, acidic (hydrochloric acid) PVC residue is very soluble in acetone and readily removed. VC is a great "second step" for PVC damage since it will remove any verdigris and it will also neutralize any remaining traces of acid.

 

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Doug - As you probably know, PCV residue contains hydrochloric acid. It reacts with copper to form copper chloride = verdigris. While I do agree that "verdigris and PVC residue are different things", the acid in the PVC residue creates verdigris (copper chloride type) - which is why the residue is always green.

I just wanted to try to make that clear for other people.

 

The product is not "wearing off" like Rick said, it is drying and polymerizing during the 24+ hour period. You cannot "over dry" but most of the process is over in 24-72 hours (depending on room humidity). I recommend getting your coins into holders within a week or two for optimum protection.

 

VERDI-CHEM is the name of my company. The product name is VERDI-CARE. Due to this confusion, I recently modified my label. Hopefully, this will take care of the problem.

 

Those coins look fantastic in comparison to what they were. You have a great product there BadThad, something that I'll use if the need arises. I made a copy of your label so I won't forget.

Bruce

 

(109) Q: Can VERDI-CARE™ be removed?

A: The product is water-soluble and 99.99+% of it can be removed using water. The ReAcT2™ layer is semi-permanent, just a molecule thick and invisible; it will remain on the surface after a water rinse. However, it can be removed with weakly acidic solutions (not recommended).

 

Thanks for jumping in to respond, Thad.

I noticed that you recommend using xylene on the copper coins. Why xylene for copper? Where are the best places to find these chemicals (acetone, xylene)? I can find acetone anywhere, but is the stuff intended to remove the pink nail polish off of my toenails the same stuff that I want to use on my coins?

 

Copper coins seem to have the ability to pick up and hold black, gummy residues. In chemist speak, these are typically long-chain, organic materials which are readily soluble in a non-polar solvent like xylene. A basic principle in chemistry is "like dissolves like". You always want to match your conservation solvent with the type of residue you are addressing.

NEVER use fingernail polish remover on coins. NEVER! It contains ethyl acetate, acetic acid and other substances that can damage a coin. You need to use 100% acetone which, along with xylene, is available at most hardware stores.

 

Personally, I wouldn't call a molecular layer a "film", since it completely undetectable by eye or even instrumentation (i.e. PCGS sniffer).

 

Deleted : Didn't read the posts above .

 

Thanks for the response on acetone and xylene.

...and thanks for developing a very useful product!

Cheers!

 

BTW, just a word on the acetone...GDJMSP sez that it can have a reaction with copper causing odd toning. Don' know for sure, but I mostly trust him. Gotta do some experiments with that.

 

I've had this happen a couple times, both times acetone kind of hazed the surface. I ran the coins though water and xylene after the acetone, then hit them with acetone again and the "problem" went away. Both times is was due to an invisible surface residue and not a reaction between acetone and copper.

 

Poorly conducted experiment based on the given information. There's no way acetone is going to photocatalyze to acetic acid under "ambient lighting". There's just not enough information given in the little summary to figure out how the experiment was conducted and whether it was scientifically sound. When it comes to chemistry papers and articles, I'm a much bigger skeptic than a believer. There are some absolute garbage papers produced every day, yet if written well enough, they will certainly convince the layman.

 

Doug you got the gist of what I said, but there is a needed separation of naturally perceived coloration of metals ( even on the quantum level) and toning which I would define as non-relativistic ( non- quantum) action of surface bonding of contaminant elements. The red mentioned in my rambling was a quantum or nano-particle association of gold, which occurs by statistical ( random) nature, and although not mentioned can change or even disappear accordingly ( quantum events can not generally be predicted), so I would not call it gold toning ( as in silver, and copper toning). None of us may live long enough to see such red appearing on our .999 gold, but also none of us may live to see any red disappear either. I accept that gold can naturally change color, but not that it 'tones' as per my idea of such . I know it may not make much sense on the surface , and I may well be wrong , but that is how I interpret it.