Hi Joe --

I sealed the bottom hingeline of the ailerons and elevators with a product available from Northeast Sailplane Products. It's a mylar strip about 1" wide -- half of one side has a tenacious adhesive. It gets fastened to the (bottom) "wing" side of the hinge line. The other side lays against the bottom of the aileron and moves/slides with the aileron (or elevator): down when the aileron goes down and keeps the gap covered when the aileron goes up. I slotted it for the control horn. In my opinion it improves the effectiveness/evenness of the control responses. As a secondary benefit it stops the screech -- the screech didn't bother me, but other people noticed that it didn't screech any more… It comes as long, sort of rolled up piece -- it was easy to put on.

Tom