Informational/observation post: Verdi-care

Discussion in 'Coin Chat' started by C-B-D, Sep 24, 2019.

  1. GDJMSP

    GDJMSP Numismatist Moderator

    I've read about it. And from what I've read the ATR is attached to the FTIR to allow the instrument to accomplish both functions. But the attachment of ATR does not diminish the sensitivity of the FTIR, it merely increases its functional capability.

    That said, it's an easy thing to test for yourself. Put some Verdi-Care on a coin, then submit it under the Secure Plus grading tier, (NGC has a similar tier), and watch what happens. The coin will come back in a problem coin slab.
     
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  3. GDJMSP

    GDJMSP Numismatist Moderator

    Correct, it will not. But that's because acetone, (and distilled water and xylene too), leave nothing behind on the coin.

    Bottom line, it will detect anything on the coin that is not supposed to be there.
     
    Nathan401 likes this.
  4. Kentucky

    Kentucky Supporter! Supporter

    From a post a couple of years ago...

    1. You like this.
    2. [​IMG]
      [​IMG]
      desertgemMODERATOR Senior Errer CollecktorModerator
      It sometimes seem that folklore and stories people made up keep recycling when if you read back through the posts, only a few methods can truly be recommended. I have been using BadThad's verdichem products on copper since they came out, and have never recommended anything else even close to it. It was developed and manufactured by a true research metallurgist chemist, and I have done experiments with many of the products with results here on cointalk. They are higher priced than many as they are made of specific organic chemicals to do the job properly. If you use 99cent store oil in your high performance car, you deserve what you get. Why use catsup, olive oil,dog or alligator dung, taco sauce, vinegar, etc. as you don't know what you are getting. Just follow the directions ( except I use a fine hair artist brush rather than a microfiber cloth) and PCGS nor NGC have detected or commented on the invisible film left. Sniffer doesn't seem to find it.
      http://www.wizardcoinsupply.com/products/verdi-care.html

      desertgem, Sep 5, 2015ReportBest Answer
      #39Unlike+ QuoteReply
     
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  5. GDJMSP

    GDJMSP Numismatist Moderator

    Apparently I'm missing something. I mean, I'm not sure I get what you're trying to say by quoting Jim's post. About the only thing I can think of is that for whatever reason you think I disagree with Jim's recommendation of Verdi-Care.

    If that's the case, you couldn't be more wrong if ya tried. I've strongly recommended Verdi-Care for many years for its intended purpose - removing verdgris.

    However, that has nothing to do with what I have said about the protective coating that Verdi-Care leaves behind coins being detectable by the sniffer, resulting in a no-grade coin. It is detectable. The question was asked, what would happen if it was used on a coin and that coin then sent in for grading. So I answered that question.
     
  6. wxcoin

    wxcoin Getting no respect since I was a baby

    So, what I get from reading the responses is that one has a better chance at getting a straight grade from a TPG if submitting a coin at a lower tier. That leads to another question, do coins in a Secure Plus slab get better prices at auction than those that aren't (at similar grades)?
     
  7. Kentucky

    Kentucky Supporter! Supporter

    All I was trying to say is that opinions are opinions, but facts are facts and he said

    "Just follow the directions ( except I use a fine hair artist brush rather than a microfiber cloth) and PCGS nor NGC have detected or commented on the invisible film left. Sniffer doesn't seem to find it."

    Not opinion, he said he did it. I remember Thad saying so too. Now I'll drop this
     
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  8. halfcent1793

    halfcent1793 Well-Known Member

    Use VerdiCare ONLY if you want to use something on your coins that you don’t understand. Their formula is not given, even on the MSDS. If you want to put it on an already junky coin, go ahead, but I wouldn’t put anything on my own coins if I didn’t know exactly what it is.
     
  9. Kentucky

    Kentucky Supporter! Supporter

    Do you have a degree in metallurgy? The inventor of this does. Do you eat foodstuff you don't understand the ingredients of...etc. etc. etc.
     
    Paul M., 352sdeer, Paddy54 and 2 others like this.
  10. Mainebill

    Mainebill Bethany Danielle

    Works good in my opinion I’ve had previously problem coins grade straight after
     
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  11. GDJMSP

    GDJMSP Numismatist Moderator

    And countless others, who have used it, have also had their coins straight graded as well. But here's the thing. The ONLY coins that are ever, stress, ever, run through the sniffer are those submitted under the Secure Plus grading tier. And that grading tier is rarely ever used because it is so expensive !

    But anyone who wants to do it, actually test it, can sure try. But know this, PCGS, and NGC, say they can and will detect it if ya do.
     
  12. BadThad

    BadThad Calibrated for Lincolns

    ATR will GREATLY attenuate the signal to the detector in FTIR diminishing the sensitivity....usually by orders of magnitude. With lab ATR, we use mirrors and diamond to reflect the signal and it weakens it. The PCGS "Sniffer" is a cobbled together system with even LOWER sensitivity than a true lab instrument due to having to reflect the incident beam off the coin. It is not near sensitive enough to pick-up a thin layer of VC on the surface.
     
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  13. GDJMSP

    GDJMSP Numismatist Moderator

    If that's true Thad then please me how it is they pick up everything else that's in layers just as thin, or even found only in isolated spots as opposed to covering the entire coin ?

    And tell me this Thad, if you've got access to an FTIR in your lab, does it pick up VC on a coin ?

    Bottom line, as for the machines that NGC and PCGS use, I'd still say the best way to test it out would be for someone to use VC on a coin and then submit that coin under the Secure Plus grading tier, and actually see if it comes back cleanly graded or not.

    If it does, I'll readily concede the point.
     
    Paul M. likes this.
  14. calcol

    calcol Supporter! Supporter

    I had a coin (nice AR commem) that was treated with Dissolve (freon 113, no longer available), which should remove PVC residue. It was submitted with the Secure option and came back in a body bag labeled PVC residue. It looked clean; so I figured the sniffer detected something. Just in case, I treated it again. Then sent it back w/o the Secure option. Sure enough, it straight-graded with no problem.

    Lesson here it that if a coin is submitted to PCGS with the Secure option and is rejected for PVC or other surface contamination, then 1. treat with acetone, THF, Dissolve or Koinsolv (these are all harmless-to-metal solvents), 2. give it a close look, 3. if it looks clean, consider resubmitting w/o the Secure option.

    Interesting to learn the sniffer is FTIR in reflectance mode. From the name, I wrongly assumed it was GCMS. Should be called "the looker".

    I wonder if a coin treated with Verdicare and then treated with acetone would lose the residue left by Verdicare and escape notice by the sniffer.

    Cal
     
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  15. Kentucky

    Kentucky Supporter! Supporter

    Gee, I don't think I have seen anyone mention THF here except for me. We used it by the tanker car full where I worked.

    Interesting to learn the sniffer is FTIR in reflectance mode. From the name, I wrongly assumed it was GCMS. Should be called "the looker".

    I wonder if a coin treated with Verdicare and then treated with acetone would lose the residue left by Verdicare and escape notice by the sniffer.

    Cal

    From the name, I thought it was GCMS also. I think Thad says that an acetone rinse will remove VerdiCare protective layer.
     
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  16. Kentucky

    Kentucky Supporter! Supporter

    Since I have never submitted a coin, I don't know. I do know that I have run hundreds of IR's and FTIR's some with ATR and ATR is a pain. The reason some residues would show up easily and some not is because some absorb the radiation more strongly than others. Kind of like how our eyes may not detect a faint yellow coloration but will pick up on the faintest red.
     
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  17. calcol

    calcol Supporter! Supporter

    I mentioned THF (tetrahydrofuran) in a post Dec of 2016. Best solvent for PVC. Anyone who has glued PVC pipe will instantly recognize the smell.

    Cal
     
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  18. wxcoin

    wxcoin Getting no respect since I was a baby

    That's why my coins turned purple.
     
  19. calcol

    calcol Supporter! Supporter

    Actually, it's primer that's purple. And, primer is a purple dye dissolved in ... guess what? ... good ole acetone. The purple is there so inspectors can see that you used it. If you want decorative PVC projects, use plain acetone as the primer.

    Cal
     
  20. BadThad

    BadThad Calibrated for Lincolns

    When they can physically see something on the coin, they can direct the IR beam to that spot. At that level of surface contamination (where you can see it with your eye), FTIR works well. However, it's more of a conformational determination to what they see visually. PCGS sees a lot of coins, they know what adulteration looks like.

    The detection is done by spectrum subtraction. For example, you move the beam to a clean area (baseline), take a measurement and save the scan. Then you move the beam over to the suspect area and take another scan. The FTIR software then subtracts the two and if any peaks are indicated you have a hit. The quality of the hits are really only decently identifying if you have a reference spectrum. In the case of an unknown, it's basically a jigsaw puzzle of complicated information where you can only infer, derive and guess.

    Yes, I have tested a VC coated coin on our ATR and it was undetectable. However, a drop directly on the ATR diamond is easily detected. With ATR being so weak with a reflected, thin layer, it just couldn't muster enough to give me anything.

    I have had quite a few people tell me privately they have had VC conserved coins successfully graded under the regular and secure tiers. I don't know the details of what they did.....but they were excited enough to want to tell me.

    Obviously, I don't much care - but I do enjoy spreading some knowledge. The bottom line with ANY TPG submission, there are NO guarantees.
     
  21. wxcoin

    wxcoin Getting no respect since I was a baby

    I appreciate your detailed information. I wonder what thresholds they use when determining which peaks are significant; what kind of noise thresholds are used. There must be some things which can cause errors in their analyses.
     
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