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 Replies: 17 / Views: 3,686 |
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Pillar of the Community
United States
1448 Posts |
I bought an 1829 Capped Bust half dollar; most here informed me it had PVC on it, and advised me to dunk it in acetone. I used pure acetone from the hardware and soaked it overnight with the reverse facing upward (reverse had the most PVC). When I checked up on the coin, I noticed the acetone has a lot of floating black debris in it. Here are the before and after pictures; the PVC or whatever it is still is on the coin (a little under E Pluribus Unim, the M in AMERICA, and the feathers of the eagle to the left of the shield). Does anyone have an recommendations for removing this PVC? Is it even PVC or is it just toning? I left it in acetone for more than 12 hours so I assume if it really was PVC, it would have been gone by now. I think the acetone removed the blackish gunk that was on the reverse more than it did the PVC(?) Before: zBSJ432mR9g~~60_57.jpg)  After (lighting was really difficult, if needed I will try to take better pictures; note the green hue surrounding the M and the feathers to the left of the eagle).    Another note, the green hue was difficult to see with really bright lights and sunlight, I had to hold it at an angle in order to see the green (hence the angled photos). Thanks for any help and insight! |
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Moderator
 United States
23522 Posts |
PVC infestation, when established, assumes a three-dimensional character and has to sometimes be "helped" with a toothpick or (preferably, because they're sharp) rose thorn to remove it. Try a second soak - it'll only need a half-hour or so - and see if you can get something sharp to move it around a bit while it's immersed in the liquid. That said, if you've observed no change whatsoever in the character of the color I'd find it an encouraging result. All the same it looks a little too three-dimensional for me to think it just toning.
Even if it's verdigris, under an acetone soak you should be able to get results picking at it with a sharp object. Could sure use sharper images of the reverse.
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Pillar of the Community
 United States
1448 Posts |
Thanks for the reply. Are you saying that I have to use the toothpick to move the coin around or do I have to to physically pick at the PVC? I am a little confused.
I heard of Qtips being used, is this a bad idea?
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Pillar of the Community
United States
3345 Posts |
dont use q-tips
he means you need to VERY carefully pick away at the verdigris with a toothpick or other sharp wooden or plastic object, those floss sticks with pointy ends would work. Be very careful is all we can say.
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Moderator
United States
23522 Posts |
Yeah, I was talking about physically picking at the crud itself, whatever it is. Using an organic pick (toothpick, thorn, etc) won't mark the coin at all itself; you just have to worry about whatever you're moving marking the coin itself. PVC byproduct crud isn't sharp enough to scratch a coin, but verdigris probably is.
The idea is, if you can find something in that green which physically moves when you pick at it, then you know you have something which has to go away. If you can't make anything move, it might well just be toning. It's tough for me to see how 3-dimensional that green is in images - that's something you've got to define with your own eyes and the coin in-hand.
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Pillar of the Community
United States
1448 Posts |
Thank you both for the clarification! I'm going to try it out with toothpicks and I'll post the results here.
I agree with you Dave, the material is an odd looking green that just can't be toning (very peculiar if it is). The tough part is going to be the feathered area but I will try my best.
Thanks again!
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Pillar of the Community
United States
2936 Posts |
The best thing I've found to remove residual corrosion after an acetone bath is a good old American porcupine quill. I bought a batch on The Bay and they work wonderfully! PG
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Pillar of the Community
United States
1448 Posts |
Thanks for the tip pale!
I used acetone and the toothpick method just now; it really didn't do much at all. I'm beginning to think this is either verdigris or a weird type of toning although it really looks like PVC. I picked at it as hard as I could without damaging the coin. I am letting the coin soak for a couple of hours and see if that does anything.
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Pillar of the Community
United States
1448 Posts |
After using acetone and picking at it with a toothpick, very little/ no change happened to the green hue. I guess I can conclude it is a strange type of toning. I'll try to get much clearer scans when I soak it again. This time, I ordered some porcupine quills and I'll see if that changes it at all. If not, I guess it's just toning! When In the liquid, it looks like the green hue is removed but after it dries and I hold it angled to the light,you can still see the green in the m and e and I'm the feathers to the left of the shield. Very strange!
Edited by Steelers72
10/03/2013 5:44 pm
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Pillar of the Community
United States
602 Posts |
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Rest in Peace
United States
3039 Posts |
Whatever you do it's a pretty coin.
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Pillar of the Community
United States
1448 Posts |
Thanks numismo. I just pray the green is simply a toning and not pvc. Hopefully my last and final attempt to remove it will provide me reassurance.
Yoshi, I am not an expert, but from my brief research pvc is polyvinyl chloride which established itself on coins as a growth; comes from being stored in albums and flips that contain pvc. Pvc flips and cases usually have a universal odor that smells sweet and are very bendable. I use saflips now which contain no pvc.
Pvc can be removed by soaking the coin in pure acetone. Does not harm the coin and is considered conservation since it does not in any way alter the original surface of the coin. Pvc is greenish and usually gives a 3d appearance, like the hue on my coin but fortunately(?) Whatever this is on my coin must not be pvc since it won't go away haha...
Usually pvc removed right away after a 15min soak without needing to pick away at it. This is why I am thinking my coin has toning, because I have soaked it multiple times for a combined 20 or so hours and have picked at it with relatively no change. I'll try once more with quills and see what that does.
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Pillar of the Community
 United States
4591 Posts |
To be strictly accurate (although largely irrelevant), it's not the PVC itself that causes the damage, it's the additive that makes the PVC flexible that is the culprit. Each company that manufactred PVC flips used different plasticizers and often different formulas over time as they changed suppliers. So it's not really like there is just ONE chemical that is causing this.
Some are soluable in acetone, others in ether, in ethanol, etc. - there's a absurd number of possibilities, some of which are safe and others will damage the coin.
-----Burton 50+ year / Life / Emeritus ANA member (joined 12/1/1973) Life member: Numismatics International, CONECA Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club Owned by three cats and a wife of 40+ years (joined 1983) Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/ |
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Pillar of the Community
United States
1247 Posts |
I have started cleaning some coins in 100% acetone, and find that using a stiff, natural fiber, artists brush works really well. It leaves no marks and does a great job of cleaning. see the post I made about the 1921 penny I found. Before I scanned the coin, it was black on both sides. After a soak in acetone and some brushing... https://goccf.com/t/159706 |
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Moderator
United States
23522 Posts |
Quote:
I have started cleaning some coins in 100% acetone, and find that using a stiff, natural fiber, artists brush works really well. It leaves no marks and does a great job of cleaning.
see the post I made about the 1921 penny I found. Before I scanned the coin, it was black on both sides. It "leaves no marks" on a coin like the one you illustrated. On a coin with anything resembling original surfaces, it will completely destroy the coin's value. I only recommend ever touching the surface of a coin with anything as a last resort. It's like an Epipen - you never really want to stick something sharp into yourself deliberately, but if death is the alternative then it's OK. |
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Bedrock of the Community
United States
20753 Posts |
If the Acetone did nothing, I'd suggest leaving whatever it is alone. Unless your really good and have a fantastically steady hand, regardlesss of the tool you use, there is always a chance of a scratch. I always say leave well enough alone. So many people say use a this or that to pick at a coin. Of course they can say anything. It's not their coin, it's yours and if it gets ruined, it's your loss, not theirs. Put the coin in a 2x2 and forget any little toning. Never play with digging, scratching, picking, etc. unless you have the hands of a surgeon. I say this with the experience of someone that has messed up to many coins.
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Replies: 17 / Views: 3,686 |
Posted 09/28/2013 4:40 pm
