Verdigris vs pvc

jesbroken

I ran across this information on CoinTalk forum today, although it originated in 2011. I found it interesting and would like to see discussion in its regards.

Thank you,

Jim

PVC is a catylist for verdigris formation created by hydrochloric acid forming cupric chloride. PVC damage and verdigris are essentially one in the same. The first step is to soak it for about a hour in acetone. At the end of the soak and while the coin is still under fluid, I would prod at the spot with a toothpick to see if it comes apart. Acetone will NOT remove verdigris, but if there's PVC holding it together it will (mostly) come off.

Flatwoods

I disagree.

PVC will come off pretty quickly with acetone.

Verdigris will not come off with acetone.



I have had a small spot of surface verdigris come off but it had nothing to do with acetone.

I have also had verdigris that a hammer and chisel wouldn't remove.



PVC and verdigris look completely different.

Neither is good but pvc is much easier to remove.



I guess my main point is that most of the verdigris I have dealt with had nothing to do with pvc as a catalyst.

Insider2

Ditto Flatwoods. I was part of that CT discussion. I learned that "patina" and "verdigris" are the same thing! Previously, I believed that "patina" was hard and "Verdigris" was the soft crud (greenish) on the surface of old copper alloys.

ricko

I agree with Flatwoods... PVC comes off with acetone...Verdigris is very stubborn and will

require a rose thorn to assist in removal and always (in my experience) leaves surface damage.

PVC can damage a surface, for sure, but if caught early will usually not leave a detectable 'footprint'. Cheers, RickO

YQQ

am not sure if you guys read jesbroken's note correctly:

"Acetone will NOT remove verdigris, but if there's PVC holding it together it will (mostly) come off."

I suggest that this statement is correct. Sometimes Verdigris comes off in "plates" when held together by PVC. If that is the case, you can consider yourself really lucky.

Broadstruck

PVC comes off asap.



Verdigris can easily take a 3 month soak in mineral oil.

Insider2

QUOTE: "Acetone will NOT remove verdigris, but if there's PVC holding it together it will (mostly) come off."



The first part it absolutely true. IMHO, The part after the comma is absolutely NUTS! PVC is an easily removed haze that MAY have etched into a coin's (patina/verdigris) hard surface. PVC HOLDS NOTHING TOGETHER! And don't bring up a coin's atoms ...LOL!

sedulous

@ricko et.al... How much more do you think 3rd party conservation can be useful for a successful outcome vs. home grown remedies like acetone, mineral oil, etc.? Perhaps there is no advantage using professional conservation? Is it 50/50 so no advantage? what difference is seen with NCS vs PCGS's conservation? Looking for pros, cons.

oreville

as a young collector, I tried to fight off PVC by coating my silver coins with mineral oil with varying outcomes.

ReadyFireAim

I only have experience with PVC haze on gold.
It's a great way of getting a really nice gold coin inexpensively because dealers will do just about anything to get rid of them.
It costs about $75 to have it PCGS conserved and re-graded.

This one had white moldy looking haze all over it.
It was MS65 & re-graded MS65+ which is a big jump in value for a 1907 (it also looks very nice now)

sedulous

@ReadyFireAim said:
I only have experience with PVC haze on gold.
It's a great way of getting a really nice gold coin inexpensively because dealers will do just about anything to get rid of them.
It costs about $75 to have it PCGS conserved and re-graded.

This one had white moldy looking haze all over it.
It was MS65 & re-graded MS65+ which is a big jump in value for a 1907...

So you are saying it can be a positive outcome for gold. Excellent feedback and thank you.

Cougar1978

Has worked me while dipping but like use Q tip - tap tap tap.

Beautiful 1907 Saint they did great job. Looks PQ to me lol. Take that any day over some darn ole brownish / green crud coin.

Many coins need dip after 3-5 yrs.

ricko

Professional conservation can provide excellent results - however, they cannot fix everything, and sometimes what is beneath the 'stuff' is nasty. Amateur work should be done on no value coins (common everyday change). Amateurs will ruin a lot of coins, that is why services charge so much - they have already perfected certain methods. Cheers, RickO

Namvet69

Over the decades, I have dug some funky vertigris covered copper coins. Initially my best removal was with olive oil but I switched to mineral oil cause oo gets rancid. Some verdigris falls away after a few months, some flakes off with a thorn nudge, some hangs on tight as a tick. There is always surface damage. Nature of the beast. Peace Roy