On Tue, 24 May 2005 14:09:09 GMT, Tomas wrote:

One of the great things about the freezer bag mod is that there is
enough resistance to hold water in a slowly lowered wing, but not enough
to stop the force of any signifigant pressure. I have found that if I
lower the wing too rapidly, I get a "blow out" of the plastic diaphram.
I am now in my third year using this method and it works great. I think
the supposition that this 1mil sheet of plastic is going to create
enough resistance to split the wing is unrealistic.
I made several blow out and reset tests.

I'm not sure if these tests are reliable.
Helmut only covered the ventilation hole of his glider with tape - and
the tape was strong enough to keep the overpressure. As John already
pointed out, you need only a small differential positive pressure to
blow up your wing.

I'd strongly suggest to email Shempp Hirth about this topic - you
should get a reliable answer quickly.


Bye
Andreas