Technically speaking...oh, pooh! Yes, it is good to seal the hinge when the elevator goes down because the lifting action of the now under cambered horizontal tail does not appreciate the "leak", but when it goes up, there is more of a vector function than negative lift...as in flat plate wings. It depends a lot on the model and such. If sealing the gap was hard, we would think of aerodynamic reasons to not do it.
Good idea but there will still be less material on the elevators. I stand by my comments.
Ken
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