If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Numismatist on PVC
There are three interesting columns in this month's Numismatist relating
to previous discussions here and touching upon the issue of truth and misinformation in numismatics. With the first, the author of the Collector's Edge column repeats the misinformation that soft flips cause PVC damage because "the chemical PVC is added to make the flips more pliable" and leaches out of the plastic onto the coins. In truth, soft flips are made of PVC, with PVC just being another name for vinyl, which is the plastic they're made of. PVC (polyvinyl chloride) on its own is rigid and needs plasticizers (typically, phthalate esters) to make it soft and pliable. It's the plasticizers that cause PVC damage. The author also incorrectly states that hard flips don't contain PVC. Some hard flips in fact are also made of PVC but have less plasticizer in them and are marketed as "safety flips," safer for coins than soft flips. Other hard flips are made of a different plastic, polyester, frequently referred to by its brand name Mylar. All this has been discussed here, on the Web, and in the Numismatist and other publications many times, yet the misinformation continues, not only by some numismatic writers but by some coin supply dealers. -- Consumer: http://rg.ancients.info/guide Connoisseur: http://rg.ancients.info/glom Counterfeit: http://rg.ancients.info/bogos |
Ads |
#2
|
|||
|
|||
Numismatist on PVC
"Reid Goldsborough" wrote in message ... There are three interesting columns in this month's Numismatist relating to previous discussions here and touching upon the issue of truth and misinformation in numismatics. With the first, the author of the Collector's Edge column repeats the misinformation that soft flips cause PVC damage because "the chemical PVC is added to make the flips more pliable" and leaches out of the plastic onto the coins. In truth, soft flips are made of PVC, with PVC just being another name for vinyl, which is the plastic they're made of. PVC (polyvinyl chloride) on its own is rigid and needs plasticizers (typically, phthalate esters) to make it soft and pliable. It's the plasticizers that cause PVC damage. The author also incorrectly states that hard flips don't contain PVC. Some hard flips in fact are also made of PVC but have less plasticizer in them and are marketed as "safety flips," safer for coins than soft flips. Other hard flips are made of a different plastic, polyester, frequently referred to by its brand name Mylar. All this has been discussed here, on the Web, and in the Numismatist and other publications many times, yet the misinformation continues, not only by some numismatic writers but by some coin supply dealers. So is any PVC-based flip really "safe" for long-term storage since they all contain some amount of plasticizers? Or should we view all claims that imply permanent safety as marketing puffery? Is Mylar the gold standard? How safe are coins in Mylar? Which commercial brand flips are made from Mylar? -mazorj, now nervously eying his enflipped hoard |
#3
|
|||
|
|||
Numismatist on PVC
mazorj wrote:
"Reid Goldsborough" wrote in message ... There are three interesting columns in this month's Numismatist relating to previous discussions here and touching upon the issue of truth and misinformation in numismatics. With the first, the author of the Collector's Edge column repeats the misinformation that soft flips cause PVC damage because "the chemical PVC is added to make the flips more pliable" and leaches out of the plastic onto the coins. In truth, soft flips are made of PVC, with PVC just being another name for vinyl, which is the plastic they're made of. PVC (polyvinyl chloride) on its own is rigid and needs plasticizers (typically, phthalate esters) to make it soft and pliable. It's the plasticizers that cause PVC damage. The author also incorrectly states that hard flips don't contain PVC. Some hard flips in fact are also made of PVC but have less plasticizer in them and are marketed as "safety flips," safer for coins than soft flips. Other hard flips are made of a different plastic, polyester, frequently referred to by its brand name Mylar. All this has been discussed here, on the Web, and in the Numismatist and other publications many times, yet the misinformation continues, not only by some numismatic writers but by some coin supply dealers. So is any PVC-based flip really "safe" for long-term storage since they all contain some amount of plasticizers? Or should we view all claims that imply permanent safety as marketing puffery? I have uncirculated coins that have been in Kointainer Saflips for thirty years without showing any signs of deterioration. But yes, all claims of permanent safety are puffery. It's that pesky entropy thing that'll getcha in the end. James the Biologically Evolved |
#4
|
|||
|
|||
Numismatist on PVC
"Mr. Jaggers" lugburzman[at]yahoo[dot]com wrote in message ... mazorj wrote: "Reid Goldsborough" wrote in message ... There are three interesting columns in this month's Numismatist relating to previous discussions here and touching upon the issue of truth and misinformation in numismatics. With the first, the author of the Collector's Edge column repeats the misinformation that soft flips cause PVC damage because "the chemical PVC is added to make the flips more pliable" and leaches out of the plastic onto the coins. In truth, soft flips are made of PVC, with PVC just being another name for vinyl, which is the plastic they're made of. PVC (polyvinyl chloride) on its own is rigid and needs plasticizers (typically, phthalate esters) to make it soft and pliable. It's the plasticizers that cause PVC damage. The author also incorrectly states that hard flips don't contain PVC. Some hard flips in fact are also made of PVC but have less plasticizer in them and are marketed as "safety flips," safer for coins than soft flips. Other hard flips are made of a different plastic, polyester, frequently referred to by its brand name Mylar. All this has been discussed here, on the Web, and in the Numismatist and other publications many times, yet the misinformation continues, not only by some numismatic writers but by some coin supply dealers. So is any PVC-based flip really "safe" for long-term storage since they all contain some amount of plasticizers? Or should we view all claims that imply permanent safety as marketing puffery? I have uncirculated coins that have been in Kointainer Saflips for thirty years without showing any signs of deterioration. But yes, all claims of permanent safety are puffery. It's that pesky entropy thing that'll getcha in the end. James the Biologically Evolved Okay, that's a good testimony to the Kointainer ones. Entropy will win in the end for all things, but before the universe settles down to an amorphous mass, a few other things will happen, like all those clear sheets of supercooled liquid (a.k.a. glass) puddling under my windows. That's going to let in the elements, which can't be good for coin storage regardless of which brand of flips you use. I'll be happy if my specimens survive without visible damage long enough for my children to appreciate what I've passed on to them. After that, it's their problem! - mazorj the Bequeather |
#5
|
|||
|
|||
Numismatist on PVC
mazorj wrote:
"Mr. Jaggers" lugburzman[at]yahoo[dot]com wrote in message ... mazorj wrote: "Reid Goldsborough" wrote in message ... There are three interesting columns in this month's Numismatist relating to previous discussions here and touching upon the issue of truth and misinformation in numismatics. With the first, the author of the Collector's Edge column repeats the misinformation that soft flips cause PVC damage because "the chemical PVC is added to make the flips more pliable" and leaches out of the plastic onto the coins. In truth, soft flips are made of PVC, with PVC just being another name for vinyl, which is the plastic they're made of. PVC (polyvinyl chloride) on its own is rigid and needs plasticizers (typically, phthalate esters) to make it soft and pliable. It's the plasticizers that cause PVC damage. The author also incorrectly states that hard flips don't contain PVC. Some hard flips in fact are also made of PVC but have less plasticizer in them and are marketed as "safety flips," safer for coins than soft flips. Other hard flips are made of a different plastic, polyester, frequently referred to by its brand name Mylar. All this has been discussed here, on the Web, and in the Numismatist and other publications many times, yet the misinformation continues, not only by some numismatic writers but by some coin supply dealers. So is any PVC-based flip really "safe" for long-term storage since they all contain some amount of plasticizers? Or should we view all claims that imply permanent safety as marketing puffery? I have uncirculated coins that have been in Kointainer Saflips for thirty years without showing any signs of deterioration. But yes, all claims of permanent safety are puffery. It's that pesky entropy thing that'll getcha in the end. James the Biologically Evolved Okay, that's a good testimony to the Kointainer ones. Entropy will win in the end for all things, but before the universe settles down to an amorphous mass, a few other things will happen, like all those clear sheets of supercooled liquid (a.k.a. glass) puddling under my windows. That's going to let in the elements, which can't be good for coin storage regardless of which brand of flips you use. I'll be happy if my specimens survive without visible damage long enough for my children to appreciate what I've passed on to them. After that, it's their problem! It's only a matter of time until some loudmouth swings through here and goes ad hominem on you for claiming that glass is a supercooled liquid. Meanwhile, here's a disquisition on the topic: http://math.ucr.edu/home/baez/physic...ass/glass.html James the Vitreous |
#6
|
|||
|
|||
Numismatist on PVC
M.Meghrig & Sons in Los Angeles manufactures flips with reduced PVC. They call it "Generic Archival" or as above author says "rigid flips". Without a minimum of PVC these holders would be unusable. Again, these aren't reduced-PVC flips, they're reduced-plasticizer flips. They're still made of PVC, which is another name for vinyl, which is the type of plastic they're made of. What you meant is that without a minimum of plasticizer the flips would be unusable. -- Consumer: http://rg.ancients.info/guide Connoisseur: http://rg.ancients.info/glom Counterfeit: http://rg.ancients.info/bogos |
#7
|
|||
|
|||
Numismatist on PVC
So is any PVC-based flip really "safe" for long-term storage since they all contain some amount of plasticizers? PVC safety flips are distinguished by the amount of plasticizers they contain, which is much less than regular soft PVC flips. Is Mylar the gold standard? How safe are coins in Mylar? Which commercial brand flips are made from Mylar? I don't think anybody has seriously studied this. I believe polyester (Mylar) safety flips are safer than low-plasticizer PVC safety flips. But I believe the difference is small, perhaps insignificant. Again, I don't think there's any evidence to back this up, just anecdotal stories. My own practice is to put the few proof coins I have in polyester flips (Kointain Saflips) and most of the rest in International Plastics' low-plasticizer safety flips, sold by among others Jake's Marketplace and FORVM Ancient Coins. I believe the low-plasticizer safety flips might be problematic in high-heat, high-humidity environments, but otherwise they're fine. I've read or heard nothing, anecdotally, to the contrary. Others like them, I know, but I personally find the Kointain Saflips ugly, with their striations, sharp corners, and flimsiness, making the coin/flip package less attractive to look at than coins in the low-plasticizer safety flips. Again, just my view for my coins. -- Consumer: http://rg.ancients.info/guide Connoisseur: http://rg.ancients.info/glom Counterfeit: http://rg.ancients.info/bogos |
#8
|
|||
|
|||
Numismatist on PVC
Reid Goldsborough wrote:
So is any PVC-based flip really "safe" for long-term storage since they all contain some amount of plasticizers? PVC safety flips are distinguished by the amount of plasticizers they contain, which is much less than regular soft PVC flips. Is Mylar the gold standard? How safe are coins in Mylar? Which commercial brand flips are made from Mylar? I don't think anybody has seriously studied this. I believe polyester (Mylar) safety flips are safer than low-plasticizer PVC safety flips. But I believe the difference is small, perhaps insignificant. Again, I don't think there's any evidence to back this up, just anecdotal stories. My own practice is to put the few proof coins I have in polyester flips (Kointain Saflips) and most of the rest in International Plastics' low-plasticizer safety flips, sold by among others Jake's Marketplace and FORVM Ancient Coins. I believe the low-plasticizer safety flips might be problematic in high-heat, high-humidity environments, but otherwise they're fine. I've read or heard nothing, anecdotally, to the contrary. Others like them, I know, but I personally find the Kointain Saflips ugly, with their striations, sharp corners, and flimsiness, making the coin/flip package less attractive to look at than coins in the low-plasticizer safety flips. Again, just my view for my coins. I just checked an unopened pack of Saflips. It says they are made of Polyethylene Terephthalate (a/k/a polyester) and that they are "inert and flexible" and "Contain no PVC or Oil." Yes, they do have the striations and sharp corners, and some of my older ones crack if I open them far enough to take the coins out. I don't know if the formula has changed or not in 30 years, but if not, I suppose they will all crack one day. At something like 15c a throw retail, that can get expensive. James |
#9
|
|||
|
|||
Numismatist on PVC
I've had some coins in PVC holders for over 40 years without any sign of
damage, perhaps it depends up the exact chemical makeup of the PVC. The PVC does appear to be of the "soft" variety but the coins are stored in a cold place, perhaps high temperatures allow the PVC to do the damage, not a problem in Scotland. Billy "Reid Goldsborough" wrote in message ... There are three interesting columns in this month's Numismatist relating to previous discussions here and touching upon the issue of truth and misinformation in numismatics. With the first, the author of the Collector's Edge column repeats the misinformation that soft flips cause PVC damage because "the chemical PVC is added to make the flips more pliable" and leaches out of the plastic onto the coins. In truth, soft flips are made of PVC, with PVC just being another name for vinyl, which is the plastic they're made of. PVC (polyvinyl chloride) on its own is rigid and needs plasticizers (typically, phthalate esters) to make it soft and pliable. It's the plasticizers that cause PVC damage. The author also incorrectly states that hard flips don't contain PVC. Some hard flips in fact are also made of PVC but have less plasticizer in them and are marketed as "safety flips," safer for coins than soft flips. Other hard flips are made of a different plastic, polyester, frequently referred to by its brand name Mylar. All this has been discussed here, on the Web, and in the Numismatist and other publications many times, yet the misinformation continues, not only by some numismatic writers but by some coin supply dealers. -- Consumer: http://rg.ancients.info/guide Connoisseur: http://rg.ancients.info/glom Counterfeit: http://rg.ancients.info/bogos |
#10
|
|||
|
|||
Numismatist on PVC
"Mr. Jaggers" lugburzman[at]yahoo[dot]com wrote in message ... mazorj wrote: .... Entropy will win in the end for all things, but before the universe settles down to an amorphous mass, a few other things will happen, like all those clear sheets of supercooled liquid (a.k.a. glass) puddling under my windows. That's going to let in the elements, which can't be good for coin storage regardless of which brand of flips you use. I'll be happy if my specimens survive without visible damage long enough for my children to appreciate what I've passed on to them. After that, it's their problem! It's only a matter of time until some loudmouth swings through here and goes ad hominem on you for claiming that glass is a supercooled liquid. Meanwhile, here's a disquisition on the topic: http://math.ucr.edu/home/baez/physic...ass/glass.html James the Vitreous Wow. Thanks for the great link. It nicely explained the science, debunked the "flowing glass" myth, discouraged the misnomer "supercooled liquid," but rightfully demurred on the unanswerable question of whether glass is a liquid or a solid. It was far superior to most of the links to documentation that pass for "proof" on Usenet. Shoulda checked first - I got the "supercooled liquid" explanation in high school physics class in the 1960s... taught by a priest. Which probably explains his reference to church glass as proof of the phenomenon. In fairness, he was pretty sharp on science (he taught our chemistry class as well) and our knowledge of sub-macroscopic properties of materials was less sophisticated in the 1960s than it is today, so this presumably was a common misperception even in scientific and engineering circles at the time. I once participated in a project that involved the effects of "super-cooled drizzle drops". From which my main take-away was that "Super-Cool Drizzle Drops" would be a great name for a candy. :-D |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
THE Numismatist once again! | Mr. Jaggers | Coins | 6 | December 20th 07 04:54 PM |
Numismatist??? | Wes Chormicle | Coins | 6 | March 18th 06 10:56 PM |
What is a Numismatist? | Crappedinmypants | Coins | 0 | January 24th 06 04:57 AM |
The Numismatist. | Ian | Coins | 21 | August 17th 04 10:38 AM |
The Numismatist--Just Another Coin Rag? | Fred A. Murphy | Coins | 70 | July 21st 04 10:13 AM |