On Monday, August 19, 2013 10:32:38 AM UTC-4, Peter F wrote:
In Richard Johnson's flight test of the original Discus he replaces the

mylar seals with internal fabric seals & gets a noticeable improvement in

performance.



The mylar on my Discus CS is 20years old & starting to lift in places, so I

will need to replace it.



Has anyone out there done the internal seal mod?

Did you think there was any advantage

Can I have both internal & mylar seals?



The pushrod holes for Aileron & Airbrake are sealed with rubber bellows.

These are also 20 yrs old.

Anyone know of a way to test whether these are perished, no longer

sealing?



Many thanks



PF

you can do something which works just as well, and is a lot easier. its something schempp-hirth is doing now i think. you stick this thin, slippery (almost like teflon or something) tape onto the wing and the control surface, which creates a perfect seal, and then go over it with the regular external mylar seals.

if your seals are as old as you say, its been time to change them for a long time.

MandH is doing it that (I think).