Re-curving mylar on a glider

No fire, a cheer. You've pointed up an important issue. Many of us have
seen replacement seals come off in a few months, even when done
professionally by reputable shops. So, we keep the factory seals on as
long as possible, and sometimes just a bit longer. Really, life would
be so much better if we could trust that replacement mylar would stick.
What are the factories doing the first time around that we aren't doing
for replacements? Is it just a better job of sanding/cleaining the
surfaces?

John Cochrane BB

I wish I knew, John. One reputable repair shop with excellent
relationships with German manufacturers expressed amazement and, to be
fair, initial concern that my seals were so old. But when I described
my situation, he said, well, if they're still attached well, replace
the safety tape and just keep an eye on them because you'll never get
new seals to adhere as well as the factory does. He said the
performance of the Mylar itself (i.e., curvature or tension) wasn't
really a question; the issue was the adhesive.

I've seen several postings that describe sanding/cleaning the surface
of both the wing and the Mylar as well as how to apply the adhesive and
the seals, the proper temperature and pressure to use, etc. But when
more than one expert says the factory stuff is much better, I, too,
have to ask what it is that they are doing different. What's the secret
formula???

In the meantime, I acknowledge some risk in leaving the old seals in
place. But I find it difficult to prove (as opposed to intuitively
"knowing") that replacing the seals makes it any less likely that I
will have a failure.

Chip Bearden
ASW 24 "JB"