RE: How do you seal hinge lines on a giant scale plane?
Do you mean the gaps between the control surfaces?? if so you can get a clearish tape from most drug stores, I think it is called "Durma-Blend" maybe not. But it will be in the area where the sell Band-aids and stuff. It is very flexiable and has some streach to it. Just apply it to the bottom of the surface between the control and the wing. Make sure you have the rudder, elavator etc. deflected all the way up, down, side to side, before you apply the tape. It will be almost invisable and seals the gaps very very good.