new window glazing strip shrinking

[63air]

Last summer I replaced all the window glazing strip on my trailer with the product sold by Vintage Trailer Supply. Since that time it has shrunk about 1/2 inch per foot of installed length. Has anyone else experienced this ? It looks like a problem with the product to me but perhaps there is something I failed to do when I installed it. Either way,I am not a happy camper and will have to redo the windows.

[InsideOut]

Sounds like you may have stretched it a bit while installing it and it is just springing back to it's original size. I know we have been cautioned against this happening. Sorry...can you use some of the longer pieces to redo the shorter lengths or is it unsalvagable?

Shari

[65CV]

63air-

Is it possible that you stretched it? I'm concerned since I've finished 3 of my 6 windows. The gasket is a bear to get in and I don't want to redo it too!

Good luck.

63GT

[63air]

I don't believe it was a stretch problem during installation beccause it seems to be increasing as it ages and I would think something like that would show up quickly. I wonder if it is a UV protection issue with the product.

[BIGED52]

63air, If it was UV damage you should be seeing other signs than just shrinkage....like cracking of the seal rubber itself. I would be very interested to see this problem before I install my replacement glazing on the "Landshark". Is your 19"er the one on North Shore Drive? If so could I make a date to see the problem in person? Thanks Ed

[greg176]

I replaced the seal on my front window two years ago and the rest last summer.So far I have seen no shrinkage of the Vintage RV seals.I was very careful not to stretch the seal on installation ,which was not easy.

[VintageRV]

Hi 63Air and all,

First, a little history...
Airstream used the Hehr Hall-Mark 12 windows from 1961-1965. To my knowledge, they have never appeared on any other brand of trailer. In 1966, when Airstream stopped using the Hehr windows, Hehr discontinued the Hall-Mark 12.

While these windows were still in production, they came standard with a brittle plastic glazing strip. Sometime after the windows were discontinued, so was the brittle plastic strip. Hehr still needed to provide support for the windows, but they did so by producing a vinyl rubber glazing strip to replace the brittle plastic. I'm guessing this was a cost savings measure, but it could have been a practical concern about shipping long plastic strips when they could just ship rolls of cut-to-length rubber in bulk.

To this day, that vinyl rubber substitute part is still made with the original material on the original tooling. To my knowledge, there is no alternative part available at this time...and there hasn't been an alternative for many, many years.

The problem...
The problem you are having with shrinkage is standard with all vinyl rubber extrusions. The blue vinyl rub rail on many Airstreams shrinks the same way. And so do old door and vent gaskets and so does the original glass seal for the older 1952-58 windows. Vinyl rubber is an "old fashioned" type of rubber and while it is highly resistant to abrasion, shrinkage is the down side.

When installing, some of the shrinkage can be reduced by doing as some have advised: "bunch," don't "stretch." But even those who have been careful not to stretch it will eventually see some gaps in the corners.

What we are doing about it...
We have made a commitment to recreating the obsolete gaskets for all post-War Airstreams. We're almost finished. We're tweaking the tooling for the few remaining 1947-49 trailers now. And we have the 1950-51 gasket prototype en route to us as of last week.

Of all the extrusions we sell for 1947 to 1965 windows, this is the only one we did not develop the tooling for. It is the only one made out of vinyl. All the others are done on tooling we've developed and they are made out of silicone rubber. Silicone is much, much less prone to shrinkage. Just this month we have finished designing our own silicone version of this bead. It is now at the toolmaker. When tooling and testing are finished, we will have it for sale. It won't be as "original," but it will be more stable.

I hope this post doesn't come across as too commercial. (If it does, Andy, please don't hestitate to delete it). I just wanted to add some background for the discussion.

Thanks,

[BIGED52]

Thanks Steve, We all apprieciate the info... Ed

[Wardinbb]

My experience with the "old" glazing strip is the same. When I installed it in 04, it was Autumn and cool, so was the garage. I compressed 'bunched' the material in place, thinking I was off-setting any shrinkage that may occur and hoping any expansion that would take place would strengthen the installation. By 2007/2008 it all shrunk. I was going to complain but read the verbage on Vintage's site about the new silicon replacement. (I see their post today as well.)Since one roll won't do it, you get to buy 2.

In a couple of windows I have been able to salvage the first installation by pressing the strips back to their respective corners and superglue-ing the corners together. This has worked where the gap was not more than 1/8-3/16.

I too am having difficulty getting the corners on the new silicon material to come out professional. I started with a jig, a 1/8x5/16 (kite stock) wood strip laid along the back of the glazing to support the material so I could 'shear' the silicon. 'Cutting', I found, produces uneven cuts. The jig also featured 45 degree ends so a razor blade could be run along the edge straight down to effect the shear cut. The jig, I cut to length 1" longer than the window frame to get the material 'compressed' in place.

What a complete farse. All that plannin' for nothin'! The angle cuts didn't work when they came together on the window and the material would not compress! My first piece in place ended up with 2+ inches of extra material! The second piece, cut to length, still came up with excess stock left over! If the angle of the cut in the corner does not match the joining corner, the width of one of the strips will be wider at the joint. It's just frustating. For someone to look at it, they would look at you sympathically and say "did that yourself, did ya?!"

I was hoping someone had posted "The Technique" to solve these issues.

I did find that by spraying the glazing strip with silicon spray helped a great deal with getting the material in place quite easilly. But an adverse impact occured to the butyle holding the glass in place. The spray tends to liquify the butyle. Next will be just dish soap to break the surface tension.

I'm gonna win, I just don't know how just yet.

[VintageRV]

As I mentioned back in February 2006, we were working on a silicone replacement for that vinyl rubber. That silicone version is all we've sold now for at least the last 18 months.

It's a no-shrink product. It has worked very well for the vast majority of customers, however, it is a snug fit and does take some pressing to get it in place (no adhesives necessary). We advise using water...or soapy water...as a lubricant if there is a problem pressing it in place, but usually that isn't necessary. If you can't get it in at all, give us a call at 800-644-4620 and we'll problem solve with you. In fact, we're happy to talk all vintage Airstreamers through their window dilemmas.

Yes, mitering the corners does seem to be the biggest pain in the you-know-what. Of course that is mostly an aesthetic thing that only an Airstreamer would care about. As a less-pretty alternative, you could do straight cuts and butt it.

[3Ms75Argosy]

I was about to say "oh no!"... but then I kept reading, and found this was a 2 yr old thread on old material. I have some of the new material sold by VTS (from the orginal poster! Thanks!) and didn't have any issues with installation or cuts. I did practice a bit with a sharp razor... I found if I cut a little less than 45 degrees, and back cut a bit (like with cove moulding for a house), I was able to get some tight miters.
I also used dishsoap to help me out with installation.
Good luck!
Marc