Wooden Boxes

Comments

• Cameonut Posts: 7,384 ✭✭✭✭✭

  June 22, 2005 8:06AM

  Interesting result, but I am not sure what conclusion can be drawn.
  
  If you had put a couple more pennies in a plastic box as a control, one could draw some conclusions as to the differences between wood and plastic.

  “In matters of style, swim with the current; in matters of principle, stand like a rock." - Thomas Jefferson
  
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• Iwog Posts: 1,089 ✭✭✭

  June 22, 2005 8:09AM

  Fingerprints on copper will guarantee eventual toning no matter where you store them. I doubt it has anything to do with the wood.

  "...reality has a well-known liberal bias." -- Stephen Colbert

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• magikbilly Posts: 6,780 ✭

  June 22, 2005 10:30AM

  There is nothing surprising about this. It is a simple fact that wood containers outgass acidic vapor, esp. those with unknown finishes and adhesives and felt/fabric, will corrode metal. Some people during the "wood threads" insisted oak was the least acidic of wood - the opposite is true. The water retention capacity (hygroscopicity) of wood is incredible - reason enough to steer clear. The only questions are how much and when - when in a slab. In a poll last year nearly 80% of the room thought that wood boxes are harmful. PCGS gas stated that the boxes are doing "just fine" and that tests are still ongoing though..I'd like to have seen independant testing and before marketing.
  
  Link To Thread With Additional Information
  
  and
  
  Another Link With Yet More Information
  
  I am pasting 2 previous posts with data for those who did not catch this topic first time round:
  
  Link to Poll showing 78.79 of Board Members voted "yes" that wood has the potential to harm coins: Poll Link
  
  From Coin Chemistry by W. White:
  
  " Before today's plastic holders came on the scene, coins were stored in drawers, specially made wooden cabinets, paper envelopes, cardboard coin holders, cigar boxes, mint-produced cardboard boxes, mint-sewn cloth bags, paper roll wrappers and other sundry devices. Most of these storage`methods exposed coins to sulfur compounds that were present either in the solid or gaseous state. In time, many specimens developed a visible surface film of metal sulfide about 25 to 125 nanometers thick"
  
  and
  
  "Organic acids are not present in the ambient air at concentrations great enough to cause corrosion within collections; but they are given off by wood and wood based products, as is formaldehyde."
  
  
  Thanks to MacCrimmon:
  "Susan Maltby has written to this issue many times in Coin World.
  She is a conservationist out of Toronto, I believe. The bottom line is, wood containers are not the best environment for storage of 'metal objects'."
  
  
  From the Art Conservation Center at the University of Denver's Judy Greenfield, Conservator of Objects - "Building a Better Case":
  
  "True African mahogany is reported to be one of the least corrosive woods, but it's expensive and difficult to procure, and other mahoganies sold as substitutes are corrosive" (Hatchfield). Additionally, mahogany is resistant to termite attack. There is disagreement over the benefits of seasoned wood. Kiln-drying (seasoning) wood helps break down and drive off some inherent acids, though it may depress the wood's RH-buffering ability (Miles). But Werner cites the Department of Industry's statement that "[seasoning] wood...accelerates the production of free acetic acid and formic acid. Most of the acid, however, remains in the wood."
  
  So, even if you are lucky and your cabinet is actually made out of true African Mahogany it is still only a lesser evil. While Mahogany is much more stable than red oak, particularly dimensionally which I imagine would play a role in cabinet making, none of this this alters the fact that wood is factually not the best choice of material in which to store coins. I continue to quote from Art Conservation Center at the University of Denver, and this information is specifically in regard to display/storage cases - not so terribly removed from coin storage. And remember, display cases in museums are often temporary and yet these matters are considered. Many of the displayed items cited in the article were metal
  
  "Although some woods are worse than others, all emit a variety of acids, aldehydes and other lignocellulosic degradation products." (Miles). Wood emits mostly acetic acid; formic acid is produced at 1/10th the amount of acetic acid(Blackshaw). Moisture hydrolyzes acetyl groups in the hemicellulose (a form of cellulose, the "building block" of wood) to produce acetic acid. Elevated temperatures appear to foster acetic acid production (Werner)." I don't know what to make of the claims about sanded mahogany - it is also agreed among conservators that all woods must have a barrier between the wood and the display case interior. "No wood can ever be completely sealed to stop emission of organic compounds, though sealants can impede emission." At least one case I saw made by Mr. Nichols appears to have the coins "exposed" to the inside finish, which IMHO should not be inside the case at all. You don't need physical contact for outgassing problems, and we know PCGS slabs are not "sealed" and plastic is gas permeable anyway. Also, the PCGS boxes are "cherry wood finish and are lined with black felt" - I don't have any idea what wood is used, what adhesives, what finish (oil /Varathane?) or what fabric. To me, once closed, the environment in a wood box is concentrated - and the wood just sits there outgassing with the adhesives and finish, waiting to absorb large qualtities of water...now if the box is in a safe.....
  
  Someone mentioned Varathane - "Even after 18 months' drying time, oleoresinous (oil) paints corroded lead in an experiment cited by Miles. As oil products dry, they undergo oxidative degradation which yields volatile organic acids, aldehydes and carbon dioxide (Miles). Oleo-resinous products include oil-modified paints and varnishes, one-component polyurethane varnishes (e.g., Varathane), alkyd paints, epoxy ester paints, aluminum paints, silicone paints and most varnishes (Miles)."
  
  The information just goes on and on...and on - ESPECIALLY about the harmful glues and adhesives that might be used in construction (perhaps more important than the wood and as important as the finish), the fabrics - fabric should not be used where humidity is not controlled (someone mentioned a tarnish retardant cloth - these can be bad - as can certain dyed felts etc.!)...all can be injurious, and usually are unless care is taken. All I am saying is that wood in not an ideal choice, or even second choice for long term coin storage. Yes, this data is about storage/display cases in museums, but most of the problems above seem are mainly influenced by humidity and temperature - variables found in every deposit box and safe. And those are concentrated environments, more than the cases in the above discussion.
  
  Best,
  Billy
  
  PS - Despite recent posts to the contrary, oak (some say the PCGS box is in fact oak) is indeed the most acidic of woods and does in fact outgas. The most acidic hardwoods include oak, beech, birch and ash. Oak is the most acidic. With a pH of 3.7 to 4.9, depending on the source (Miles, Stamm), it is capable of liberating up to five percent of its weight in acetic acid (Erhardt)." Brazillian Mahogany, as apparently used by Mr. Nichols, is apparently properly called Honduras Mahogany and IS NOT true African Mahogany and does not share the same "stability" as the African source above - "other mahoganies sold as substitutes are corrosive" (Hatchfield)". I have no idea what wood Mr. Nichols uses other than what he states on his website. As stated above about Mahogany though, regardless of seasoning or kiln drying "most of the acid, however, remains in the wood." I have no issue with Mr. Nichols fine and attractive cases, this is not an attack on his cases nor do I wish to engage in any further discussions about his work as I do not even know him.
  
  
  I, and others, have quoted as many sources as I can in an attempt to shed some light on this subject, including of course the Art Conservation Center at the University of Denver, the Library of Congress, Coin Chemistry by W. White, The Merck Index of Substances, the Intercept Patent and the opinion of some conservator from Coin World. There are more sources. Mr. Spud, who is actually interested in general conservation and not particularly these boxes, has quoted more sources and additional information than I care to list - literally. In addition, 78.79% of board members who voted in the previous poll thought the boxes have the potential to cause harm. Answers #2 and 3 in this poll, which "admit" there is the potential for harm, well - as of this writing almost 77% voted that way here as well. That is what this is about - potential. The one article from the University of Denver about storing metal in wood cases - the one even you said provides solid evidence they are not safe, is enough to put me off the idea - especially as I have no "pro" argument to counter it with. The "pretty" factor means little to me - about as much as the "Limited Edition" part.
  Now, do I have "SOLID proof" as you put it? NO - as in I did not complete tests on these specific boxes myself - but then apparently neither has PCGS. Nor do I need to have solid proof - I did not sell them apparently without testing them. I am merely trying to raise an issue that seems important to me. However, I do know that wood is a no-no in many other areas of collecting and conservation, and there is a body of established data that bears that out - storage in wood is clearly not the best of ideas for metal objects - and it has no advantages that have been raised that I have seen. And it is not just wood - it is the adhesives used, the fabric and so on. The slabs are probably the just about the best thing going. But, as we do know that slabs are not "airtight" and are gas permeable, I do not think I will choose to store mine in a known concentrated acidic environment. Especially if it hasn't even been tested yet, as seems to be the case (no pun there). Even if the potential is deemed "possible but unlikely" - what is there on the other side of the issue that would induce me to chance my collection? Because the boxes are pretty? What am I missing here? Are there other advantages I am not seeing? They don't fit into deposit boxes (thank god) as someone mentioned. So, what is it then that makes people ignore a reasonable potential and want to even possibly risk their coins - some worth many thousands of dollars each - risk 30 coins at a time to the tune of $50 a box? To accomplish what exactly? They can't be determined to be inert - even if they were determined to be 90% safe with 90% certainty, why take a chance with a collection that has taken time, effort and money to assemble?
  
  Best to you,
  Billy
  
  
  CARING FOR YOUR METAL OBJECTS
  The American Institute for Conservation of Historic & Artistic Works
  Prepared by Julie A. Reilly with assistance from David Harvey and Julie Lauffenburger, 2001.
  
  
  "The characteristic tarnish on silver is black silver sulfide. Acidic gasses from wooden cabinets and cases can also cause metal corrosion. Vapors produced by plywood and other products that off-gas formaldehyde cause lead alloys and other metals to corrode, forming wispy white crystals often confused with mold growth. Keeping metal objects in a clean, dry, safe environment can prevent deterioration from environmental sources."
  
  "Metals, in general, should be stored with inert storage materials. For example, metal cabinets and shelving should be used rather than wood cabinets and shelving. As discussed earlier, many woods and wood products, like plywood, emit acids and other gasses that cause metals to corrode. Acidic newsprint and cardboard boxes should be avoided. Acid-free, lignin-free wrapping paper and boxes are better. Clean, soft cotton cloth can also be used."
  
  and:
  
  Link to Data - if this doesnt convice you there is potential for harm from wood boxes nothing will
  
  "Original" Wood Post (sent to Mr. Hall Aug 5th, responded Sept. 14th....just 3 days after my ORIGINAL Poll (below) closed where 78.79% voted "wood has the potential to harm coins")
  
  Original PCGS Wood Poll Thread (more data)
  
  Link To Another Wood Thread
  
  

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