Will PVC damage gold coins?

Discussion in 'Coin Chat' started by ksparrow, Oct 16, 2015.

  1. ksparrow

    ksparrow Coin Hoarder Supporter

    A question for our resident chemists. I remember reading that a number of the Bass collection gold coins had pvc, but I never saw proof that the coins were damaged. Given that coins are made from a gold alloy, could the HCL produced by the PVC plasticizer and humidity actually corrode the surface of them?
     
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  3. rzage

    rzage What Goes Around Comes Around .

    Good question !
     
  4. jwitten

    jwitten Well-Known Member

    I have had lots and lots of gold in every kind of holder, and never had one rejected for pvc damage.
     
  5. gxseries

    gxseries Coin Collector

    Given that gold coins are often alloyed with copper and gold coins can tone, I would not be surprised that they can be damaged by PVC. The damage however would be less obvious.
     
  6. SuperDave

    SuperDave Free the Cartwheels!

    I could only imagine PVC plasticizer nastiness taking hold in an area of very poor alloying quality where the copper was prominent. Gold itself simply laughs at both PVC and hydrochloric acid.
     
    Paul M. likes this.
  7. physics-fan3.14

    physics-fan3.14 You got any more of them.... prooflikes?

    Gold will not be affected by HCl, but the alloys will.

    If you really want to dissolve some gold, you need to go with aqua regia instead.
     
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  8. GDJMSP

    GDJMSP Numismatist Moderator

    Then the answer is yes, gold coins can be damaged by PVC.
     
  9. It's not just the PVC which is the issue, but also room temperatures. in cool or cold environments PVC is more likely to capture moist, and thus damage the coins.
     
  10. ksparrow

    ksparrow Coin Hoarder Supporter

    Has anyone here actually seen a PVC-damaged gold coin? (not just a gold coin with green stuff on it).
     
    NOS likes this.
  11. ldhair

    ldhair Clean Supporter

    Yes. I have a quarter eagle that was covered with PVC. It had damage under the areas with the most PVC. With that said, once the PVC is gone there is no way to know what the cause of the damage was.
     
  12. ksparrow

    ksparrow Coin Hoarder Supporter

    Thanks, Larry. I have seen it asserted elsewhere that PVC on gold does not need to be removed as it can't damage it. Do you know if the damaged areas on your coin look like the acid ate into the metal? That's what I have seen on silver, rough patches.
     
  13. ldhair

    ldhair Clean Supporter

    I wish I had an image. It's not really as rough like it is on silver. It's more of an odd look to the luster and color. Tough to describe.
     
  14. ksparrow

    ksparrow Coin Hoarder Supporter

    Thanks for trying!
     
  15. StrongCoins33

    StrongCoins33 Love Conquers All.

    I noticed some green on this coin it’s gold and a ms61 PCGS
    Should I be concerned its pvc?
    I tried to take the best picture I can. C0586FB0-1B8C-4E3B-BC81-39F8DDA7FFFD.jpeg
    C0586FB0-1B8C-4E3B-BC81-39F8DDA7FFFD.jpeg AC3FE71C-DF1F-4E35-8D11-2749C485927B.jpeg 5E09E49E-9233-414A-8E2B-5610F8CB392A.jpeg AC3FE71C-DF1F-4E35-8D11-2749C485927B.jpeg
     
    Last edited: Oct 11, 2018
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  16. desertgem

    desertgem Senior Errer Collecktor

    Was it on the coin when sent in for slabbing, or did it occur later, or was it purchased that way?
    Without water vapor it will most likely stay at that level. If you are not displaying it , I would put it into a zip lock bag with a small pack of desiccant until you decide to break it out, clean off the PVC and then sell or reslab. Since 90% gold has copper, some small damage might be done and show if removed, I would keep it slabbed. IMO Jim
     
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  17. StrongCoins33

    StrongCoins33 Love Conquers All.


    Go it this way when purchased and wondering if the damage over time is worth it to keep it or return it.

    Thank you very much for your thoughts.
     
  18. GDJMSP

    GDJMSP Numismatist Moderator

    Jim didn't come right out and say it but it's verdigris, not PVC. And I agree with his assessment, it's nothing to worry about as long as you store the coin properly.
     
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