PVC Residue or Organic Material Reaction with Acetone

appletree

Will either PVC residue or an organic material react on a silver or gold surface with acetone to produce a haze or a waxy looking substance?

1960NYGiants

Only if not rinsed properly.



Soak in acetone to loosen the material. Repeat in virgin batch and rinse with deionized water. If haze appears repeat process. If haze remains then the surface has been compromised. PCGS and NGC offer restoration processes that may remove the haze.

georgiacop50

What kind of container are we talking about? Glass? Styrofoam? Polypropylene?

zippcity

Originally posted by: georgiacop50

What kind of container are we talking about? Glass? Styrofoam? Polypropylene?

I believe a glass container for acetone with a screw on lid to prevent evaporation would be the optimal choice for something other than a quick dip. No Styrofoam as it will melt. Don't have a clue about polypropylene.

ricko

Contaminated acetone could definitely leave a residue on gold or silver... the acetone should be changed if the coin is really cruddy and the last immersion should be in totally clean acetone... and the acetone should be of lab quality.

Proper rinse technique would be alcohol followed by DI water.... Cheers, RickO

TwoSides2aCoin

Maybe not PVC, if that's the reaction to acetone. Perhaps a glue/adhesive ?

appletree

Originally posted by: ricko
Contaminated acetone could definitely leave a residue on gold or silver... the acetone should be changed if the coin is really cruddy and the last immersion should be in totally clean acetone... and the acetone should be of lab quality.
Proper rinse technique would be alcohol followed by DI water.... Cheers, RickO

Thank you for the guidance. Yes, all in glass containers. I knew about the acetone followed by dH20, didn't know about the alcohol rinse. I'm not sure what the waxy haze is. It is very disconcerting. Under the assumption acetone would not react with an inert metals.

Repeat and see what happens.

??

BAJJERFAN

It's hard to imagine that something on the coin surface is reacting with the acetone. More likely that whatever the stuff is, it just isn't very soluble in acetone. Try it again, but after you remove the coin let the acetone evaporate and see what kind of residue [if any] remains. Since I don't know what other solvents ou might have access to, you could try soaking it in gasoline to see if that takes the crud off. You could get rid of the gasoline by spraying the coin with acetone or alcohol. If you wash with DI water, make sure that it won't cause more crap [from residual solvent] to be deposited onto the coin. Most chemists who wash glassware with DI water follow up with an acetone or alcohol rinse to remove the water, esp. if they have an immediate need for the item/s.

element159

Isn't there a possible reaction between acetone and copper? I kind of remember somebody saying that. Since silver and copper coins are alloyed, and contain copper, there could be some possibility of a reaction with those coins.

JCLIGHTBRIGADE

I have never used water after acetone, is there a consensus in this

davewesen

I have seen times when the pvc was a thin film over entire coin when exposed to acetone gelled up. I use a cotton tipped wood handled swab and roll over the surface to clean this stuff up, being careful on a circulated coin not to take too much dirt off.

appletree

Originally posted by: element159
Isn't there a possible reaction between acetone and copper? I kind of remember somebody saying that. Since silver and copper coins are alloyed, and contain copper, there could be some possibility of a reaction with those coins.

I was told copper will react with acetone depending on the copper planchet preparation. Some early Lincoln cent proof planchets were prepared with harsh acidic rinses. The metal remains vulnerable to a surface reaction with acetone. Never with alloyed gold or silver. Hindsight, shouldn't have messed with the coin. Expensive lesson.

Thank you.

clarkbar04

Originally posted by: JCLIGHTBRIGADE
I have never used water after acetone, is there a consensus in this

I rinse it off quickly, my theory is that anything removed by the acetone could remain in suspension. At the rate acetone evaporates, any suspended matter would remain high and dry on the surface of your coin.

younique

So, consensus is acetone, virgin acetone, then di. How long in the acetone & would acetone melt something like adhesive material?

mr1931S

So, consensus is acetone, virgin acetone, then di. How long in the acetone & would acetone melt something like adhesive material?

An acetone bath is one of the safest and most effective ways to remove surface contamination,to include PVC,on a coin.

As for acetone melting adhesive material,many a glued on "s" has fallen to the bottom of the beaker after the 1909 S V.D.B. hopeful has spent a little time in acetone.

Cougar1978

It does not leave haze from dipping. Rinse thoroughly and be careful how you dry especially proofs. A special basket for dipping rolls can be handy.

Soft plastic roll tubes (from mint) can leave black on ASE coin edges. This can result in return from buyers. Guy in coin club had this happen then had to dip and scrub edge of them all then the roll sold no problem. Perhaps storage in a hard plastic tube may be better.

byknow

Which type. Gin,whiskey or bourbon...

deefree49

I have a 1915 Lincoln Matte Proof with some nasty spots on the obverse. Will acetone damage the matte surface? It would have to be broken out from the PCGS holder and sent for a new grade which is risky but it really looks very distracting right now. Amazingly it is currently graded PR65RB in an OGH.



Any ideas to help? Thanks to anyone who replies...

lkeigwin

Depends on the nature of the spots. Acetone is only good at removing organic material. So it will do nothing if they're toning spots or some kind of environmental damage.



Sounds like the sort of thing I'd send to PCGS for restoration. It's likely it will be returned in its original OGH, declining conservation. But I'd trust PCGS and their experience.

Lance.

lkeigwin

Originally posted by: appletree

Originally posted by: element159

Isn't there a possible reaction between acetone and copper? I kind of remember somebody saying that. Since silver and copper coins are alloyed, and contain copper, there could be some possibility of a reaction with those coins.

I was told copper will react with acetone depending on the copper planchet preparation. Some early Lincoln cent proof planchets were prepared with harsh acidic rinses. The metal remains vulnerable to a surface reaction with acetone. Never with alloyed gold or silver. Hindsight, shouldn't have messed with the coin. Expensive lesson.



Thank you.

Acetone will not harm metal. Copper included.



But, acetone will react with surface contaminants. And that can change the appearance of some copper pieces, even those that have not circulated but have been exposed to contaminants in the air, let's say.



Acetone may also give a coin a "dried-out" look after dissolving and removing all surface oils. A little coin conditioner can help restore a more natural look (Blue Ribbon, CoinCare, e.g.) but experience is valuable so you might experiment with coins with little value first.

Lance.

deefree49

Hi Lance



Thank you for your informative reply. I remember reading something similar elsewhere but figured it wouldn't hurt to see if anyone had further experience. Copper is notorious for getting those carbon spots and while I'm not 100% certain, these look more like carbon than anything else. Your advice sounds like a best alternative and if PCGS won't touch it then I should probably just learn to live with it. I appreciate your helpful advice.

lkeigwin

Good luck, deefree. Sadly copper spots are usually permanent and there's nothing that can be done. PVC and verdigris that haven't sat too long are exceptions. Yes, copper is very sensitive to spotting, as you say.



I've tried to learn to live with it but I am never able to overlook it. Experienced collectors and dealers are quick to see them and say "no thank you". As I get better replacements I sell, usually taking a loss, and chalk it up to tuition.

Lance.

deefree49

Well said Lance. I like your tuition analogy. That particular lesson is a very important one for copper collectors.