On Aug 13, 9:40*pm, Tom Nau wrote:
I fly an ASW-28. The under-surface of the wing has a nice little piece
of plastic that covers the dump valve and which is hinged by a piece
of cloth tape. When flying with water ballast my assumption is that
correct procedure is to leave the piece of plastic in place, but open
and hanging down from the cloth tape hinge. I am thinking that airflow
will keep the plastic closed and be more aerodynamic over the dump
valve but when dumping ballast it will open sufficiently to let the
ballast dump efficiently. Or should I simply remove the piece of
plastic entirely when carrying water ballast? *Thanks.
Tom

That's how they're supposed to work.

Tape them closed when flying dry so you don't rip them off. Don't
forget to take the tape off when you put on water ballast. (Add "check
dump covers" to your preflight)

When inevitably they fall off, replace with any flat piece of plastic.
I find that the clear plastic case that holds 3m vinyl electrical tape
which I use for wing tape works great, and I usually have a large
supply of that around.

There is a larger issue of tips and tricks for water ballast which
others have covered. Some additional points:

-It is important to adjust CG using the tail tank. It's hard enough to
thermal with water without a far forward cg

-The glider is designed to carry enough water for the strongest
conditions imaginable -- smoking ridge day, 1000k attempt at Ely, etc.
On most days you do not need or want full water. Half water is a good
place to start.

- Takeoff with water ballast is harder. Carefully brief your wing
runner that the wings must be level and balanced -- no force up or
down. He or she may have to slosh the water through the internal
baffles to get it level and balanced. There must be no up or down
pressure. Ask the wing runner to let go briefly to show you there is
no pressure if you're in doubt. The wing runner must then run like
crazy, without pushing up or down. This is a good time to use partial
spoilers for roll control. Needless to say all this gets more fun at
high altitude, hot, cross-downwind at a contest. Release early if you
drop a wing!

-Enjoy! I like flying with water. It's a big performance increase for
free.

John Cochrane