Window Seal Replacement
In real life, the gasket
is smushed a lot more than depicted above.
But hopefully you get the idea. The harder the wind blows, the firmer
the lips press against the glass. |
When I got my 1967 Overlander almost
two years ago, among the first repair parts ordered were new window weather
seals because the existing ones looked so bad, and everything I had read
encouraged me to “replace them now”.
But as the refurbishment got underway, I noticed that the original
window seals, while seriously smushed, eroded & sometimes green with algae,
were doing a fine job of keeping the rain out while more serious refurbishment
issues were addressed. In fact, by the
time we made our first camping trip, only three of the Airstream’s seven
windows had been resealed. And since it
rained on us while in transit on that first trip, and no water got inside,
resealing the remaining windows dropped real low on the priority list.
But between being tired of
looking at the old seals’ appearance, and developing a fear that the smushed
seals may freeze to the windows with a possible chance of breaking one of them
should I need to move the Overlander while it is frozen, I decided to finish
the effort. Below is the original
factory seal; If you look closely, you
will see that it is a double-lipped seal like the graphic above indicates.
While I am sure there are many
ways to remove the old seal, I found running a box cutter’s blade between the
seal & the frame to work well. Do
it right, and the entire seal can be removed intact which makes measuring the
new one easier. After that, a putty
knife works well to remove the gasket’s remains. The [yellow] glue, however, does not scrape up very easily.
I read where someone suggested
using a wire brush to clean the frame in preparation for new seals. I found it to be a bust as the friction
generated by the brush (I tried a variety of grits & shapes) heated up the
remaining glue and made it re-stick with a vengeance.
After the bulk of the gasket
was removed, acetone cleaned the remaining adhesive with minimal effort. The wire brush was, however, handy for
smoothing the aluminum window frame where it had pitted.
The seal material is sold by
the foot. When cutting to fit, make
sure to cut it an inch or two too long as it will be trimmed to exact fit as
the installation ends. If it comes all
wadded up, you may want to lay it out straight in the sun to let it
un-kink/un-twist.
Don’t go overboard when buying
your adhesive. I mail-ordered mine, and
the vendor recommended four tubes of the stuff. The tube below had done three of my seven windows when this
picture was taken. I have since completed
my resealing task, and found that one tube was sufficient.
Replacing seals is not that
tough, but you need to pay attention to the old seal’s features, if there are
any, around the hinge. The Type II
windows on my ’67 do not come off (at least not easily!), and the gasket must
be trimmed to accommodate the added glass bar’s added thickness. The original seal, trimmed of it’s lips, is
pictured below:
Interestingly, on one side of
one of my windows, the seal stopped
at the glass bar, and the space was filled with silicone rubber. Go figure.
But it did not leak.
The 3M Super Weatherstrip Adhesive has instructions for use on the side
of the tube. Basically, apply a thin
coat of adhesive to both surfaces, allow to dry, apply another thin coat to one
surface only, and assemble immediately.
When my other three windows were done, I skipped the “apply another thin
coat” step per the advice of something I read on the Internet. Either way appears to work fine, but I do
feel more comfortable with the extra step.
Applying the glue can get
messy, so feel free to wear latex gloves.
I prefer to dance on the edge of getting chemical poisoning, so I just
clean my fingers when acetone when necessary.
You have to work quick because the adhesive dries fast, especially on a
warm day. Do not squeeze out too much
at once or it will skin over & be unspreadable. I find squeezing the tube with my left hand, and immediately
spreading the glue with my right index finger to work well. Be sure to practice on scrap.
The picture below shows one
seal with glue applied drying. Be sure
to arrange the seal so that the area with the glue applied is not touching
anything.
To apply the seal, start at
one of the top corners, and slowly set the seal in position. Before you have to turn a corner, go back
and firmly press the seal against the frame.
When you are within three or four inches of the other top corner, trim
the seal for both length & the glass bar before proceeding.
When attaching the seal to the
window frame, be careful to not stretch the seal as the added tension could
cause the seal to pull away from the corners.
Align the seal as close to inboard edge as possible. And, most importantly, make sure the lips
are facing out (take another look at the opening graphic, if necessary, before
starting).
When done, keep an eye on
where the seal had to turn the corners as it will want to pull away from the
frame until the adhesive dries. This is
due to the way the seal is being required to bend with respect to it’s
shape. If you are doing several windows
at once, you may want to keep a mild spring clamp or equivalent on the
corners. Once the windows are closed,
the issue goes away.
The next step involves the use
of silicone spray. Regular use (my
owner’s manual indicates yearly) will
keep the seals soft & pliable.
Silicone spray is required
after installing new seals or the glass will grip against it when being closed,
and dislodge the seal since the new rubber has not had a chance to conform to
the ‘closed’ position. However, the
timing of it’s use is somewhat subjective.
Some Airstream authorities recommend letting the adhesive dry for many
hours or even overnight before spraying the seals. Two problems – 1) Unless watched closely, the seal could pull up
from the corners during that time. 2)
Comfort level/weather report with leaving the windows open.
I allowed the adhesive to dry
for around an hour, total. 15 minutes
after the corner bend looked like it was going to stay put, the seal was
sprayed, and the window cranked down.
Pay close attention to the corners as the lips will not necessarily want
to lay flat. At an appropriate point
during the window being closed, slide a putty knife between the glass & the
corners to guide the seal’s lips into the proper, “lay flat” orientation. Do not worry about the excess silicone spray
running down the side of your Airstream.
It will not hurt anything other than leaving a shiny trail behind it.
My seals came from an
Airstream dealership, so I assume it was the best possible replacement material
for my original seals. However, even
after installing the seal as far inboard as possible, the ends of the lips
still protrude outside the glass more than I would aesthetically like:
Among the spare parts that
came with my Airstream was 10 or 15 feet of window seal purchased in the early
seventies. In the picture below, the
new seal is on the left. Notice how
much taller it is than the old seal?
It is not a big deal, but it is
worth mentioning. And, before you close
the window, be sure and give the window crank & catches a shot of spray
lube. Other than yearly maintenance, I
hope to be good for another 38 years!