'Xylene' - Is it a suitable product for use on Bronze AND Silver coins?

Discussion in 'Ancient Coins' started by Topcat7, Oct 4, 2017.

  1. Topcat7

    Topcat7 Still Learning

    (Without opening the debate "To clean, or not to clean"),
    Verdi Chem (manufacturer of 'Verdi-Care') promotes the product 'Xylene' as a coin 'cleaner'. (See picture below.)
    I haven't seen this product mentioned as a viable coin cleaning product (on this forum) before, so I am asking the question(s)
    (A) Is it suitable for use to clean LRB's?
    (B) Is it suitable for use to clean 'silver' coins?
    (C) What precautions should be taken when using it for this purpose?
    and another question -
    The article mentions 'Verdigris' (a lot) but describes B.D. (corrosion).
    (D) Should we read 'B.D.' for 'Verdigris', when reading the item?
    Thank-you.

    Magical Snap - 2017.10.05 06.34 - 124.jpg
     
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  3. desertgem

    desertgem Senior Errer Collecktor Supporter

    Both have similar hazardous warnings, but I would put them in personal use in the same order as Thad has. Acetone is made in very small quantities in human metabolism, xylene is not ( my reason). He has them listed by chemical polarity which determines what type of organic or nonmetallic material can be dissolved. Both are considered safe for use in a well ventilated, flame free environment. Do not drink or allow the vapor content to become excessive ( dizziness, light headed, etc.). Do not use a bong when cleaning your coins :)
     
  4. paddyman98

    paddyman98 I'm a professional expert in specializing! Supporter

    IMHO... Xylene should only be used to clean metal Xylophones :rolleyes:
    DV016_Jpg_Large_467974_235_concert_frame.jpg
     
  5. Kentucky

    Kentucky Supporter! Supporter

    "I haven't seen this product mentioned as a viable coin cleaning product (on this forum) before, so I am asking the question(s)" You must not have looked very much, it has often been mentioned.
    A-yes
    B-yes
    C-don't snort it don't use around flames
    D-Sure, if you want to.

    A little more...some people claim acetone can discolor copper coins, but xylene won't. Xylene will remove organic stuff...ie sticky gummy stuff...from coins. Otherwise, @BadThad might want to comment.
     
  6. Kentucky

    Kentucky Supporter! Supporter

    might strip the paint
     
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  7. chrsmat71

    chrsmat71 I LIKE TURTLES!

    Wait.....so I shouldn't clean my bong with Verdi-care? Now you tell me!
     
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  8. gsimonel

    gsimonel Well-Known Member

    Actually, B.D. (bronze disease) and verdigris are not the same. Left untreated, bronze disease will eventually destroy your coin. Untreated verdigris will leave you with a coin with verdigris. It pretty much just sits there, looking a bit smug.
     
  9. GDJMSP

    GDJMSP Numismatist Moderator

    I would guess well over a thousand times. I say that because I've been talking about and recommending using it for as long as CoinTalk has existed (15 years now) - and that's just me, not all the other members.

    Yes they are, bronze disease is nothing more than very old verdigris. From a chemical point of view I don't know that this is the right word to use but I think it kind of gets the meaning across, bronze disease is just verdigris that has become calcified over time.

    Correct, as long as there is no moisture present. However, if there is moisture present, and yes that even includes the humidity in the air, and since there is always humidity in the air, the verdigris will continue to slowly eat away at and destroy the coin.

    Now granted you can greatly slow down the destruction caused by verdigris if you limit the humidity in the air as much as possible. But the only way to stop it is to remove it.
     
  10. Barry Murphy

    Barry Murphy Well-Known Member

    Verdigris and Bronze disease ARE NOT the same thing. Verdigris is stable, doesn't spread, doesn't grow, cant jump from one coin to another. Bronze disease is active, can show up overnight on a spot that was previously clean and showing no signs of verdigris, can jump from one coin to another.

    Barry Murphy
     
  11. Oldhoopster

    Oldhoopster Member of the ANA since 1982

    Bronze disease is a reaction where copper in the coin react with chlorine/chlorides and forms a copper chloride. Chlorine can come from a lot of different sources. This is a self sustaining reaction and will continue to eat away at newly exposed copper, until either all the chlorides are removed or the copper is gone.

    Verdigris is a catch all term for organic junk that forms on the surface of a coin. It may or may not cause damage to the original surface. Depending on the composition, distilled water, Acetone, Xylene, all, or none may remove it.

    I do not consider inorganic deposits such as horn silver, rust, Bronze disease, etc as verdigris, but will not complain if others do. Just my personal preference

    I have never used Verdi-Care, but based on posts from Doug and others whose opinions I respect, it is a very good product.

    Hope that helps
     
  12. Oldhoopster

    Oldhoopster Member of the ANA since 1982

    Avoid the coins with smug verdigris. Stick with the contrite verdigris instead :wacky:
     
  13. lrbguy

    lrbguy Well-Known Member

    The statements about verdigris the VerdiChem has given are ambiguous at best and mistaken at worst. As others have said here, Bronze Disease is not to be lumped together with Verdigris on coins. That writer appears to lump them together, and then expounds vagaries in a non-scientific way. I would dismiss those comments and search for more precise statements, since you are asking about the relative merits of distinct chemicals on an indistinct set of problems (i.e. coins with different chemical natures.)

    Will VerdiChem remove copper acetate?

    What will Verdichem do with cuprous or cupric chloride?

    Why is does one of the standard treatments for Bronze disease use sodium sesquicarbonate, which is not mentioned in the list of chemicals to be used?

    Ask real questions and get real answers, not marketing hype.
     
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  14. GDJMSP

    GDJMSP Numismatist Moderator

    Ask a chemist, you'll find out they are.
     
  15. Insider

    Insider Talent on loan from...

    Barry Murphy, posted: "Verdigris and Bronze disease ARE NOT the same thing. Verdigris is stable, doesn't spread, doesn't grow, cant jump from one coin to another. Bronze disease is active, can show up overnight on a spot that was previously clean and showing no signs of verdigris, can jump from one coin to another."

    I'll add one thing. Verdigris will eventually damage the underlying surface.
     
  16. eddiespin

    eddiespin Fast Eddie

    @Topcat7, xylene is paint-stripper. It's explosive, and it will make you "punchy" (as in kill your brain cells), if you inhale it. That probably explains why collectors who use it recommend it, they're missing a few.
     
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  17. desertgem

    desertgem Senior Errer Collecktor Supporter

    ? Where did this come from ? Verdigris is a metallic copper compound.
    The acid that initiates the effect is almost always ( in the coin world) due to PVC plasticizers containing plastics. It is mainly Copper acetate and/or copper carbonates, whereas Bronze disease ( which needs moisture ) to initiate a copper chloride reaction towards hydrochloric acid formation ( see below URL for chemistry). Both are a copper compound formation problem. If water and PVC is removed from a coin with verdigris, the reaction will halt. If water is removed from Bronze disease, it will halt and form the crystal pattern that can be transferred to unaffected coins. BUT it does not move itself, it does not Jump. Disease is not a proper name to give such, as it is not alive nor organic. So both conditions are copper reactions, both require moisture. Once removed neither problem will return if proper storage conditions are maintained.

    Modern coins can get Bronze disease's classical symptoms as well as ancients can get Verdigris.


    https://www.brown.edu/Departments/Joukowsky_Institute/courses/greekpast/4867.html
     
  18. Pishpash

    Pishpash Well-Known Member

    I always enjoy these discussions. I am not a chemist, far from it. As an ancient collector I really don't care. To me, verdigris is the green stuff on coins. I call the bright green, rock hard deposits, malachite. So long as they are stable it is OK with me. Bronze disease might not be a scientific term but the description tells me a whole lot about the state of my coin. Verdi-care is not meant to cure BD, it should be used when the BD has been eliminated to prevent (or help to prevent) its return.
     
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  19. lrbguy

    lrbguy Well-Known Member

    I did. They're not. The hard green substance we have been calling "Verdigris," does not contain chlorine ions. What we have been calling "Bronze Disease" is only the chloride or chlorate compound on the surface. That is the way it is regarded in the literature conservators use. Those of us who have not adopted that convention, might want to get with it. (Or not, as they choose.) BTW the acid that produces copper acetate is, drumroll, acetic acid (think vinegar). And if that is in the air, it will react with any exposed copper, with or without the interference of PVC.

    Pishpash gave a fine take on the problem in non technical language. Bravo dear lady!
     
    Last edited: Oct 5, 2017
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  20. Kentucky

    Kentucky Supporter! Supporter

    Then ask another one. I am an organic chemist and as such know more about organic chemistry than inorganic chemistry. Verdigris is a loose term for corrosion on copper and can be copper acetate, copper chloride or copper carbonate (guess which acid copper carbonate comes from...drumroll) or a combination of any of these, or other copper containing compounds. I think @BadThad can speak to this much better than me, but it's kind of like the difference between tarnish and toning. If you like it, it's toning...if you don't like it, it's tarnish. If you have a green coloration on a coin that is stable, it's a patina called verdigris, if it has a tendency to spread, it's bronze disease. Green toning on copper coins makes me uneasy and I would just as well remove it. I have removed green toning using VerdiCare, but, once again I will let @BadThad address that. BTW, sodium sesquicarbonate is the accepted treatment for bronze disease as you would have seen if you had been on here for awhile.
     
  21. eddiespin

    eddiespin Fast Eddie

    If it's someone else's coin, it's cleaned...if it's your coin, it's conserved.

    I think you started something, Kentucky... :)
     
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