Mounting Disaster?

I just finished going through some older albums looking for stamps to scan for the Queen Victoria designs thread. These are books that, in parts, have not been accessed often in the past 5 years and which were assembled initially at least 25 to 30 years ago. At least, some of the mounts are that old.

I discovered, to my consternation, that some of the mounts had gone completely brittle, with the plastic crumbling or tearing apart. It affects both the black background and the clear display side. These were the Hawid Brand mounts (most likely)and how widespread this is remains to be seen as I obviously have some looking to do.

Has anyone else encountered this. Obviously some repair and reconstruction is required and you might want to have a quick look at your older material. It seems to be in both Harris and Stanley Gibbons preprinted country albums; the Harris with glassine interleaving and the Gibbons without.

The picture may give some sense of what I am seeing.

I have seen the Mylar strips fall off the
black "Hagner" stock sheets of Australia,
I have just presumed the plastic adhesive has weathered due
to poor husbandry.
I've not seen the mylar go brittle.

It is getting scarier as I research this. This type of mount is now and always has been made from PVC plastic. If fact if you look at ads, companies specifically advertise that this is the type of plastic being used. The varying flexibility comes, I beieve, from differing amounts of stabilizer used to accomodate the specific purpose.

PVC does deteriorate and, relatively speaking, fairly quickly. The best example I can think of is old photo sleeves from photo albums that have gone orangish and/or brittle. Both things are symptomatic of deterioration.

I have located two articles so far that describe the changes that occur in plastics without getting too terribly technical.

http://mmics.files.wordpress.com/20...eck-list.pdf

http://www.vam.ac.uk/res_cons/conse...n/index.html

After reading them, I am really going to do some more homework to see if there is anything else available. I also have had another look through those old albums and in areas where the set-up is more than 25 years old, I would say that about 20 to 25% of the mounts are affected to some degree though most not as disasterously as the one I found this morning.

Mylar is supposed to an inert material. It's supposed to last about a hundred years. It's what they use to protect paper stuff and I use it regularly for my comics. I would be more concerned with the black mounting paper. Most paper has acid in it and it gets absorbed into other paper products.
All the old pages and supplies I have are from Lighthouse and I have not seen them break like that.

I have been waiting on a reply to any one of half a dozen emails sent to various manufacturers. My current (Wednesday) theory - and this may easily change by Thursday, is that the older mounts which I used 35 years ago were of a slightly different and less stable formulation and that was what I was asking about. If so, then simple replacement of decaying mounts will work and let my kids worry about it.

Oh, and as far as I can tell and I am not a chemist, Mylar is simply a copyrighted name for one type of PVC plastic. 100 years? That's what they say though none of it is that old. What I have only lasted about a third of that and all plastics will decay. Something to be said for stamp hinges with some version of boiled hooves as glue - now that is apparently as stable and inert as it is possible to get!

I thought that I would update an old topic and one of my constant "Whatever can I do?" very plaintive queries because I notice that a very similar issue arose again in a new thread that can be reached with this link.

https://www.stampcommunity.org/topi...LY_ID=170706

None of the mentioned manufacturers responded in any way to my enquiries - somehow, I am not that surprised. And I have been slowly going through the oldest books and replacing mounts as required. It appears that in books over about 25 years in age, an increasing proportion are turning brittle.

First symptoms appear to be a seperation of the clear front from the black back, then the black crumbles and the clear portion usually remains intact. Again, no apparent damage to the stamp.

This is, of course, only a problem with those stamps which have never been moved or reorganized and that, luckily, is a manageable proportion of the collection.

I have had this happen quite often:




Never quite understood it either, although I have to say that the mounts that are brittle were from older albums (i.e. 1970's perhaps) and I think the quality has improved over time.

I have never had such a problem with newer mounts, so I think it is indicative of the type of material used in earlier days.

I started to use White Ace albums in the early to mid-1960's. At that time, I started to use Showgard mounts (I still have my "Showgard Vidimeter 'for really accurate mount measurements'" - copyright 1962). After reading backroad's experience, I just went through all of my White Ace album pages. Every mount is still as flexible as when I first used the mount. Could the problem be the album pages or where the albums were stored?

For clarification I should say that the stamps in question were mounted between 1965 qnd 1975 (roughly). The paper used was good quality quadrille, packaged and sold by stamp dealers under more than one brand name, and while I cannot say for sure that it was acid free, archival quality, it does not show any discoloration at all. Some was white and some was black with a white net but this does not seem to have any impact on whether or not the mounts were affected.

Stamps and mounts have had minimal exposure to light and the albums are stored upright on shelves with light pressure (the shelves are full but not jam-packed). Humidity in this area is low, very low in the winter, and temperatures are not extreme in the summer, so temperature range in the house is usually between 65 F to 75 F at the extremes.

The majority of mounts are Hawid Brand though I cannot swear that all were the same. That was what was available to me at that time.

Nothing unusual to set these apart from what most people do.

I think everyone has somewhat different experiences with plastic products and I agree that the result could easily have been due to different chemical formulae used in manufacture at that point in time. Just be aware that problems can occur and keep an eye on your collection.

"Oh, and as far as I can tell and I am not a chemist"

I'm sorry that just struck me funny...
That's pretty scary that those mounts deteriorate like that. It makes me double think my album idea.

I recently transitioned my US collection from a Scott Minuteman to a National album. The mounts in the Minuteman, all black Showgard, were placed between 1979 and 1985. None showed any sign of deterioration.

How would this work with clear mounts? I've never really been a big fan of black background mounts because they look like something the dog dragged in when they're cut wrong. I prefer lighthouse clearmounts. None of the ones I've used during the early 90's have any problems. That said, what about those "Treat Mounts" with the self-adhesive on the back? I bought and used some of those back in the day when I was "collecting on a shoestring" and I worry for the stamps I mounted in them.

I have no idea why I bothered to save this junk all these years, but almost anything (even hinges!) would be better than the yellowed, old, Crystal Mounts from the 1960's and 1970's. Here's one unused example I've kept all these years and, yes, it has yellowed considerably even without anything mounted inside:



I'm not even sure who the manufacturer of this one was, but it contains the "adhesive" mounting strip as referred to in an earlier post. Must have gotten it as a "free sample" along the way. Never quite trusted it enough to use it on anything important:



If my experience is typical of other collectors, some of these mounts were acquired when I was a youngster and my budget didn't allow for me to look at "quality" mounts. They were expensive and on a kid's allowance and the cheaper stuff looked okay when they were new. I don't think anyone 30 or 40 years ago would have stopped to think about adhesives, acid-free paper (did they even have it back then?), or chemicals contained in stamp mounts as a determining factor for what to buy, when price was the major consideration.