Discussion - Member to Member Sales - Research Center
Discussion - Member to Member Sales - Research Center
Do any members know the first US stamp that used PVA gum? I want to sequester them for
stamp soaking/pressing, as they tend to not come as clean and continue to stick to other
stamps. I would also like to do some research on how to completely remove this crud and
pass my knowledge on to other collectors. If anyone has any info or ideas on completely
removing this gunk that would also be much appreciated.
Thank you in advance.
Just stickin' around....
TuskenRaider
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Hi Everyone;
I just did some looking around on Wikipedia, and read somewhere that PVA adhesive contains
Boric acid and has a PH of 5.5! Should these be soaked in an Alkiline bath first to neutralize
the acid and then fresh water before drying?
Any chemists out there that want to weigh in on this? 
Still stickin' around.... 
TuskenRaider
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Hi Everyone;
Wow, didn't think I could find a topic or question that stumped all the membership.
Please everyone don't feel bad tho, I did numerous Google searches on the first use of
this stuff on US stamps, and nothing found was even close to what I wanted to know.
Everything I did find was so general, I at first thought my computer was infected with
a virus!!
I have almost NEVER been disappointed with Google until now. I even tried different
wording in the search string. Anyone have a clue what I did wrong on Google. I even
used the browser tool "find in this page".
I also looked in Scott's catalog, and nothing there either. Apparently this is a little
known and elusive trivial fact. Couldn't even find it in Sear's catalog either, alto they
had some great tools in there tho. I guess I had too much coffee that morning!
My guess is that it was first applied to a definitive and used on several different
definitive issues before being used on Commemoratives.
I not sure, just a guess tho....
TuskenRaider
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From Wikipedia
Self-adhesive stamps
In recent years, the use of self-adhesive stamps, otherwise known as pressure-sensitive stamps, has become widespread. This relatively new form of stamps has a release carrier backing that has the same pressure-adhesive backing as the stamp itself. Therefore, the stamps can be released easily from the backing and placed onto a postal envelope. The first use was by Sierra Leone in 1964,and the United States tried it later on a 1974 Christmas stamp; this was judged a failure and was not reintroduced until 1989 when it gradually became widespread. In the 1990s, the U.S. Post Office began transitioning from water-based stamps into the use of self-adhesive stamps. By 1995, only 20 percent of the thirty-five billion stamps the Post Office produced every year were self-adhesive, yet by 2013 almost all U. S. stamps issued had become self-adhesive.
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Hi Everyone;
No wonder I had a difficult time getting an answer. I'm sorry everyone, as I'm not very
good at expressing myself and a poor communicator, and often get folks upset at my
poor choice of words.
The gum I'm referring to isn't self-stick. This gum has no release paper backing!
It is a dull almost invisible water activated gum and is called out as PVA. I read that
when first used it was too hard to tell if the stamps were gummed or not because it is
a dull gum and mostly invisible. It was later tinted slightly to give a yellowish appear-
ance. When soaked, it doesn't come off completely, and when stored in envelopes
with other stamps it sticks to them.
I know it was used on some transportation coils, but do not know what US stamp it
was first applied to. I want to sequester them for soaking/pressing. I have about 20,000
US stamps to soak/clean/press/dry and sort for approvals. Want to find out how to get
this stuff off before I soak all of them so I don't have to do them twice.
I also read that this adhesive was not originally developed for use as stamp gum. It was
favored for some uses because it has the ability to be re-moistened and re-used. This is
a bad thing for stamps if it is not very thoroughly removed.
Still stickin' around....
TuskenRaider
Login to Like
this post
TuskenRaider,
I had never heard the term PVA gum before, but I am familiar with dull gum on Transportation coils (like 2225b). I collect mint and don't sell, so it's never been an issue for me. The only adhesive I ever made an effort to remove was the caustic gunk on the back of 1552. I hope you can find someone with useful advice. If not, go with your instincts and add some baking soda to the water you use to soak the stamps off of piece. Then rinse with fresh water and see if the results are better. If you still have problems my next try would be to soak briefly in Ronsonol, air dry, and rinse in fresh water.
But I have to ask, is all this effort worth it? Can you not segregate these items or leave them on piece? If not, I would experiment with inexpensive examples first, obviously.
Lars
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Hi Larsdog;
All these stamps are already off paper and they stick to everything when left for several
days. The gunk isn't solvent soluble like self-sticks, and it was only used by the US for a
decade or two until they switched to self-sticks. Probably why not many people know
much about the stuff. I've also heard it called Poly-Vinyl Acetate.
It leaves a dull gritty appearance on the backs. My guess is that it needs many hours of
soaking at an elevated temperature like 120-150F.
You are so right about 1552. It was such a big failure, that it caused the stamps to turn
a dingy yellow, sometimes even before they were sold. The USPS is just like Microsoft,
they don't beta-test anything! Do you remember the Canadian mint stamps that were
the first victims of phosphor tagging and this caused the stamp to yellow terribly. Well I
got stuck with a mess of them!
I will definitely find a fix for this stuff and report to everyone how it works, even tho I'm
not a alchemist.
Just stickin' in there....
TuskenRaider
Login to Like
this post
"All these stamps are already off paper"
So if you are trying to neutralize the effect for your own purposes, I wish you success in your efforts. If these are stamps to be sold, would it not be easier to place them in inexpensive mounts? I have a mint 2225b in a Showgard mount in my album and just checked it. No adhesion whatsoever and no evidence of discoloration. It has been there for at least 5 years.
If you're trying to fix a problem, stamp mounts may be the answer. If you're trying to solve a mystery, please keep us informed of your progress. Sounds interesting!
Lars
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I wonder if this is the same type of gum that Sweden used on their issues back in around the 1980's-1990's. I could never tell at first glance if mint stamps had gum on them or not.
Mike in NC / meostamps
PS..If it was, maybe a Google search on Swedish stamps might pull up some info..
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Here's my understanding of PVA adhesives: There is a bit of confusion with the term PVA. Written as such it can mean Polyvinyl Alcohol, or Polyvinyl Acetate. To distinguish between the two, PVAL is sometimes used, to mean Polyvinyl Alcohol.
Perhaps the USA was different but British Commonwealth issues changed from gum arabic (GA) to Polyvinyl Alcohol (PVAL), towards the end of the 1960's. Sometimes this is referred to as PVAD or DEX; polyvinyl Alcohol with added dextrin.
Polyvinyl Acetate (also known as PVA) was used in the gumming of postal stationery. I think there were (are) instances of both types of PVA mixed together.
As all of these are water soluble, temperature may just be the key factor. PVAL has a high boiling point. So perhaps a good soak in very warm water might be needed.
I have noticed from my used copies of Hong Kong QEII high values from the late 1960's/early 1970's, some still have gum patches. These issues were produced firstly with gum arabic and then PVA. So I can only assume that the patchy ones are PVA(L).
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Hello - from my Chem. Eng. background
If what you are referring to is PVA
PVAlcohol is manufactured from PVAcetate (no need to get techie on how its done)
PVAlcohol is used for coating food supplement tablets as a moisture barrier & for adhesives
(that would probably make it a GRAS product - Generally Regarded As Safe)
PVAlcohol melts at a fairly high temp so hot water probably won't do it.
It is fairly resistant to any product dissolving it.
It will dissolve to some extent in alcohol - so you might try that (rubbing alcohol) but you probably need ethanol (the kind you drink)
Added note - saw Dextrin mentioned above - don't know if it is added but quite possible. Children's school glue probably has it. Dextrin is considered healthy if you decide to eat it.
I guess that kid back in grade school knew something I didn't.
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Hi Everyone;
I thank you all for your input. I'll try all these suggestions and report my failure or
success as appropriate.
Still stickin' in there....
TuskenRaider
Login to Like
this post
The original gum arabic was brown,treacly and liable to cause the paper to split when applied too thickly,although quality control improved later. Although I am not a chemist I think that this was an extract from tree bark or sap. PVA is thinner, lies flat and inert when applied to paper. Also I think that this less liable to stick to the sheet of stamps below. According to one catalogue I have gum arabic gives stamps a tendency to curl,while PVA is lie flat ( although personally I think that humidity might affect that tendency somewhat).
PVA soaks perfectly well in any water warmer than lukewarm, and is absorbed easily by blotting paper from the back of the stamp.
However I am sure that there are additives ( including but not exclusively dextrin ) as with British stamps in particular some values in some periods are likely to stick to plain paper when pressed in a stack after soaking, while others are not. I am sure that the exact formula for the PVA - or the condition under which it is applied to the paper varies, and this effects the way that it acts when soaking.
I know that US ( as well as UK, which is what I am more familiar with ) now buys its stamps from various different sources, who may obtain papers,inks and gums from even more varied suppliers. Various mint Machin stamps can be identified by different shades of PVA from different manufacturers, but of course these varieties have to be identified by different methods on used copies.
All these points do not of course answer the original question, but unless a particular stamp was issued on both gum arabic and PVA does it matter, other than as background interest ? It is of course possible that there is not a simple answer anyway, as during a given period repeat orders of definitive stamps might be on one gum, while newly issued commemoratives could be on another.
Malcolm
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I do not know if this thread is continued, but having worked with stamp removal for a while, the easiest and fastest way to get them off and clean is to use denatured alcohol as the solvent. If you dip the stamp in, wait about 5 seconds, and take it out, the stamp should easily come free from the envelope. Dip again, and clean the back with a QTip or tissue. You should have a perfectly clean stamp. WARNING! test the stamp first! This method will affect some of the inks used, so so not try it out on expensive stamps!
As to the first US Stamp to use PVA gum, I am thinking around 1980, with the Windmill booklet stamps.
As to #1552, the infamous XMAS self adhesive stamp, they can still be removed from the backing and the "gunk" removed. Best to use d-limolene though- most other solvents do not work well.
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Hi Everyone;
Do any members know the first US stamp that used PVA gum? I want to sequester them for
stamp soaking/pressing, as they tend to not come as clean and continue to stick to other
stamps. I would also like to do some research on how to completely remove this crud and
pass my knowledge on to other collectors. If anyone has any info or ideas on completely
removing this gunk that would also be much appreciated.
Thank you in advance.
Just stickin' around....
TuskenRaider
Login to Like
this post
re: What is first known use of PVA stamp gum?
Hi Everyone;
I just did some looking around on Wikipedia, and read somewhere that PVA adhesive contains
Boric acid and has a PH of 5.5! Should these be soaked in an Alkiline bath first to neutralize
the acid and then fresh water before drying?
Any chemists out there that want to weigh in on this?
Still stickin' around....
TuskenRaider
Login to Like
this post
re: What is first known use of PVA stamp gum?
Hi Everyone;
Wow, didn't think I could find a topic or question that stumped all the membership.
Please everyone don't feel bad tho, I did numerous Google searches on the first use of
this stuff on US stamps, and nothing found was even close to what I wanted to know.
Everything I did find was so general, I at first thought my computer was infected with
a virus!!
I have almost NEVER been disappointed with Google until now. I even tried different
wording in the search string. Anyone have a clue what I did wrong on Google. I even
used the browser tool "find in this page".
I also looked in Scott's catalog, and nothing there either. Apparently this is a little
known and elusive trivial fact. Couldn't even find it in Sear's catalog either, alto they
had some great tools in there tho. I guess I had too much coffee that morning!
My guess is that it was first applied to a definitive and used on several different
definitive issues before being used on Commemoratives.
I not sure, just a guess tho....
TuskenRaider
Login to Like
this post
Auctions
re: What is first known use of PVA stamp gum?
From Wikipedia
Self-adhesive stamps
In recent years, the use of self-adhesive stamps, otherwise known as pressure-sensitive stamps, has become widespread. This relatively new form of stamps has a release carrier backing that has the same pressure-adhesive backing as the stamp itself. Therefore, the stamps can be released easily from the backing and placed onto a postal envelope. The first use was by Sierra Leone in 1964,and the United States tried it later on a 1974 Christmas stamp; this was judged a failure and was not reintroduced until 1989 when it gradually became widespread. In the 1990s, the U.S. Post Office began transitioning from water-based stamps into the use of self-adhesive stamps. By 1995, only 20 percent of the thirty-five billion stamps the Post Office produced every year were self-adhesive, yet by 2013 almost all U. S. stamps issued had become self-adhesive.
Login to Like
this post
re: What is first known use of PVA stamp gum?
Hi Everyone;
No wonder I had a difficult time getting an answer. I'm sorry everyone, as I'm not very
good at expressing myself and a poor communicator, and often get folks upset at my
poor choice of words.
The gum I'm referring to isn't self-stick. This gum has no release paper backing!
It is a dull almost invisible water activated gum and is called out as PVA. I read that
when first used it was too hard to tell if the stamps were gummed or not because it is
a dull gum and mostly invisible. It was later tinted slightly to give a yellowish appear-
ance. When soaked, it doesn't come off completely, and when stored in envelopes
with other stamps it sticks to them.
I know it was used on some transportation coils, but do not know what US stamp it
was first applied to. I want to sequester them for soaking/pressing. I have about 20,000
US stamps to soak/clean/press/dry and sort for approvals. Want to find out how to get
this stuff off before I soak all of them so I don't have to do them twice.
I also read that this adhesive was not originally developed for use as stamp gum. It was
favored for some uses because it has the ability to be re-moistened and re-used. This is
a bad thing for stamps if it is not very thoroughly removed.
Still stickin' around....
TuskenRaider
Login to Like
this post
re: What is first known use of PVA stamp gum?
TuskenRaider,
I had never heard the term PVA gum before, but I am familiar with dull gum on Transportation coils (like 2225b). I collect mint and don't sell, so it's never been an issue for me. The only adhesive I ever made an effort to remove was the caustic gunk on the back of 1552. I hope you can find someone with useful advice. If not, go with your instincts and add some baking soda to the water you use to soak the stamps off of piece. Then rinse with fresh water and see if the results are better. If you still have problems my next try would be to soak briefly in Ronsonol, air dry, and rinse in fresh water.
But I have to ask, is all this effort worth it? Can you not segregate these items or leave them on piece? If not, I would experiment with inexpensive examples first, obviously.
Lars
Login to Like
this post
re: What is first known use of PVA stamp gum?
Hi Larsdog;
All these stamps are already off paper and they stick to everything when left for several
days. The gunk isn't solvent soluble like self-sticks, and it was only used by the US for a
decade or two until they switched to self-sticks. Probably why not many people know
much about the stuff. I've also heard it called Poly-Vinyl Acetate.
It leaves a dull gritty appearance on the backs. My guess is that it needs many hours of
soaking at an elevated temperature like 120-150F.
You are so right about 1552. It was such a big failure, that it caused the stamps to turn
a dingy yellow, sometimes even before they were sold. The USPS is just like Microsoft,
they don't beta-test anything! Do you remember the Canadian mint stamps that were
the first victims of phosphor tagging and this caused the stamp to yellow terribly. Well I
got stuck with a mess of them!
I will definitely find a fix for this stuff and report to everyone how it works, even tho I'm
not a alchemist.
Just stickin' in there....
TuskenRaider
Login to Like
this post
re: What is first known use of PVA stamp gum?
"All these stamps are already off paper"
So if you are trying to neutralize the effect for your own purposes, I wish you success in your efforts. If these are stamps to be sold, would it not be easier to place them in inexpensive mounts? I have a mint 2225b in a Showgard mount in my album and just checked it. No adhesion whatsoever and no evidence of discoloration. It has been there for at least 5 years.
If you're trying to fix a problem, stamp mounts may be the answer. If you're trying to solve a mystery, please keep us informed of your progress. Sounds interesting!
Lars
Login to Like
this post
re: What is first known use of PVA stamp gum?
I wonder if this is the same type of gum that Sweden used on their issues back in around the 1980's-1990's. I could never tell at first glance if mint stamps had gum on them or not.
Mike in NC / meostamps
PS..If it was, maybe a Google search on Swedish stamps might pull up some info..
Login to Like
this post
re: What is first known use of PVA stamp gum?
Here's my understanding of PVA adhesives: There is a bit of confusion with the term PVA. Written as such it can mean Polyvinyl Alcohol, or Polyvinyl Acetate. To distinguish between the two, PVAL is sometimes used, to mean Polyvinyl Alcohol.
Perhaps the USA was different but British Commonwealth issues changed from gum arabic (GA) to Polyvinyl Alcohol (PVAL), towards the end of the 1960's. Sometimes this is referred to as PVAD or DEX; polyvinyl Alcohol with added dextrin.
Polyvinyl Acetate (also known as PVA) was used in the gumming of postal stationery. I think there were (are) instances of both types of PVA mixed together.
As all of these are water soluble, temperature may just be the key factor. PVAL has a high boiling point. So perhaps a good soak in very warm water might be needed.
I have noticed from my used copies of Hong Kong QEII high values from the late 1960's/early 1970's, some still have gum patches. These issues were produced firstly with gum arabic and then PVA. So I can only assume that the patchy ones are PVA(L).
Login to Like
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09:16:21am
re: What is first known use of PVA stamp gum?
Hello - from my Chem. Eng. background
If what you are referring to is PVA
PVAlcohol is manufactured from PVAcetate (no need to get techie on how its done)
PVAlcohol is used for coating food supplement tablets as a moisture barrier & for adhesives
(that would probably make it a GRAS product - Generally Regarded As Safe)
PVAlcohol melts at a fairly high temp so hot water probably won't do it.
It is fairly resistant to any product dissolving it.
It will dissolve to some extent in alcohol - so you might try that (rubbing alcohol) but you probably need ethanol (the kind you drink)
Added note - saw Dextrin mentioned above - don't know if it is added but quite possible. Children's school glue probably has it. Dextrin is considered healthy if you decide to eat it.
I guess that kid back in grade school knew something I didn't.
Login to Like
this post
re: What is first known use of PVA stamp gum?
Hi Everyone;
I thank you all for your input. I'll try all these suggestions and report my failure or
success as appropriate.
Still stickin' in there....
TuskenRaider
Login to Like
this post
06:41:43am
re: What is first known use of PVA stamp gum?
The original gum arabic was brown,treacly and liable to cause the paper to split when applied too thickly,although quality control improved later. Although I am not a chemist I think that this was an extract from tree bark or sap. PVA is thinner, lies flat and inert when applied to paper. Also I think that this less liable to stick to the sheet of stamps below. According to one catalogue I have gum arabic gives stamps a tendency to curl,while PVA is lie flat ( although personally I think that humidity might affect that tendency somewhat).
PVA soaks perfectly well in any water warmer than lukewarm, and is absorbed easily by blotting paper from the back of the stamp.
However I am sure that there are additives ( including but not exclusively dextrin ) as with British stamps in particular some values in some periods are likely to stick to plain paper when pressed in a stack after soaking, while others are not. I am sure that the exact formula for the PVA - or the condition under which it is applied to the paper varies, and this effects the way that it acts when soaking.
I know that US ( as well as UK, which is what I am more familiar with ) now buys its stamps from various different sources, who may obtain papers,inks and gums from even more varied suppliers. Various mint Machin stamps can be identified by different shades of PVA from different manufacturers, but of course these varieties have to be identified by different methods on used copies.
All these points do not of course answer the original question, but unless a particular stamp was issued on both gum arabic and PVA does it matter, other than as background interest ? It is of course possible that there is not a simple answer anyway, as during a given period repeat orders of definitive stamps might be on one gum, while newly issued commemoratives could be on another.
Malcolm
Login to Like
this post
08:34:45pm
re: What is first known use of PVA stamp gum?
I do not know if this thread is continued, but having worked with stamp removal for a while, the easiest and fastest way to get them off and clean is to use denatured alcohol as the solvent. If you dip the stamp in, wait about 5 seconds, and take it out, the stamp should easily come free from the envelope. Dip again, and clean the back with a QTip or tissue. You should have a perfectly clean stamp. WARNING! test the stamp first! This method will affect some of the inks used, so so not try it out on expensive stamps!
As to the first US Stamp to use PVA gum, I am thinking around 1980, with the Windmill booklet stamps.
As to #1552, the infamous XMAS self adhesive stamp, they can still be removed from the backing and the "gunk" removed. Best to use d-limolene though- most other solvents do not work well.
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