Eric is getting soundly hammered for trying to extend the life of his
mylar seals, so I'll add some fuel to the fire.

My ASW 24 mylar seals will be 15 years old in a few months. Yeah, they
don't quite touch the aileron control surfaces when they're in full
positive deflection, but otherwise they look fine (wings and tail). And
there's an internal seal underneath so I'm not worried about leakage.

I did replace the safety tape this year and that was overdue. I had
noticed a few edges lifting up last year (it's on my checklist, too,
see below) but simply taped them down until I could replace it. The
adhesive on the safety tape was, indeed, powdery--at least on the upper
surfaces, but when I tugged on the mylar, it seemed fine. Perhaps
because the mylar is thicker (less UV transmitted) and is itself under
a layer of safety tape? The adhesive under the safety tape on the
underside of the wing was more difficult to remove than the
upper-surface stuff.

I'm very safety conscious. And I have direct experience with seals
lifting up: my old LS-3 began pitching down suddenly one year at the
U.S. nationals when carrying water ballast because a few inches of the
cloth sealing tape on the elevator upper surface was lifting up about
1/2 cm in the airflow. It was difficult to find at first because it
looked fine on the ground.

That said, the downside of replacing mylar seems to be that, for some
reason, you'll never get it stuck as well as the factories do it. Or so
I hear from some of the experts. There have been numerous threads on
this subject on RAS in the past and I'm not surprised that owners have
to replace their seals every few years once they've ripped the original
ones off. I've also heard some horror stories of guys who replaced the
mylar at some expense and trouble and then had it lift off within a
year.

I'm careful with mine: the ship is never tied out and it lives in the
trailer with control locks that keep the surfaces in the neutral
position.

And so far it still looks good, just like Eric's. So I'll probably
watch it and replace only when it's given me a reason to.

Fire away!

Chip Bearden
ASW 24 "JB"