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Green spots on a lot of coins, not sure if PVC damage or corrosion of some sort?

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slingerUK
Joined: 8-Jun-2018
Posts: 3
They've been kept in money bags in shoeboxes in a cupboard. I've been going through and trying to separate all these coins. Are they recoverable cheaply or should I just scrap the lot of them? I've heard that they can spread which means they're likely all infected? If I start putting them in 2x2s will it stop the corrosion?

Here is a sample : https://imgur.com/a/gtx6ALF
Trp
Joined: 10-Mar-2012
Posts: 144
I would just clean them (with acetone/alcohol/Fairy) and put into 2x2s. Then if ever get a better example just replace it.

I have couple of low value coins with bronze disease and I won't cure them. They are in 2x2s and progression of disease is very low. Eventually they are gone, but that may be after many many decades.
neilithicman
Joined: 22-Nov-2017
Posts: 313
If it comes off with Acetone then it'll just be residue from being stored in a PVC container, if it doesn't come off then it could be corrosion.

I'm not sure if the member "Fluke" is still on this site, but he liked to play with corroded coins by firing them with a blow torch (search up his posts on verdigris removal) if he's still around he might like some to play with.
What? Me Worry
Giobruno
Joined: 15-Sep-2016
Posts: 170
Quote: "neilithicman"​I'm not sure if the member "Fluke" is still on this site, but he liked to play with corroded coins by firing them with a blow torch (search up his posts on verdigris removal) if he's still around he might like some to play with.
​He's still active, he posted something on these days.


I saw the photo, green spots on nickel coins are not that hard to remove, copper/bronze are more complicated, by my experience. And your coins are relatively recent, you won't have problems at removing the spots.
MIMAEL
Joined: 25-Dec-2016
Posts: 196
Hello colleagues
Do not make expensive and precious coins-leave it to the expert!!
Already in the past this problem has been addressed. This is a green coating of PVC long-stored coins.
I will show my solution.
They sell everywhere in technical stores, Seal removing. Spray content (butanone, toluene, methyl)
Who can enter the product name can download a safety data sheet with a composition.
It does not damage the coin patina

my green coins before cleaning:



the spray foam reacts, and a green coating with dirt, bubbles and stays on the foam then just wipe gently







toluene and methanol in the spray
fine preservative oils


It's my way, please also for your opinion. I warn you not to make rare coins.
Ivan
slingerUK
Joined: 8-Jun-2018
Posts: 3
@neilithicman:

It's several thousand coins which are ruined. At this point i'm pretty devastated and feel like giving up on the hobby, that's 10+ years of collecting gone in about 6 months. A lot of them are low value, but i have a lot of pre-war copper/bronze which are all ruined too, even some in 2x2s. Seems to be corrosion and not PVC because only 1 silver coin has it, which i guess could be PVC damage from a prior owner.
https://imgur.com/a/EmwrDwC
@Giobruno
Recommendations on how? If i just 'pick' off the spots, wont it just reappear?

@MIMAEL
Thanks, i will try a couple of methods and see.
slingerUK
Joined: 8-Jun-2018
Posts: 3
https://imgur.com/a/zqVk0Rv

I tried using degreaser and a q-tip, it removes the green, but i think they look worse...
halfdisme
Joined: 6-Oct-2017
Posts: 469
I once purchased the remaining coins in the stock of a coin cutter. Many of them had small spots, and these were because he stored them openly near his water-cooled saw.

Humidity will spot them--including the humidity from breathing on them, if they are not in holders.

If it is humid in your cupboard, or if you do not live in a smoke-free environment, you can also get spots.

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