Brief Description: Aileron/Flap Hinge Brackets Filler
The gap between the aileron/flap hinges always seemed to look a little odd. I thought it would make covering the wing and painting more difficult. I’ve seen other builders on the web that have filled these gaps with plywood. I decided to fill mine with balsa wood. Balsa is much lighter than plywood and while not as strong as plywood, it is very strong when impregnated with fiberglass resin. I bought some ¼ inch balsa board at a hobby store. I cut pieces to fit between the gaps leaving the top and bottom oversized and trimming the rear dimension to clear the hinges on the control surfaces. I prepared the aluminum surfaces by roughing them up with 120grit emery paper and then cleaning with acetone. I mixed fiberglass resin with fumed silica to thicken it to a consistency about like jam. I wanted the resin thick so it would not run and to fill in any voids between the aluminum and the wood. I covered the trailing edge around the brackets with masking tape to protect it from resin. I coated the surfaces of the balsa fillers and clamped them in place. I put parchment paper between the clamps and the brackets in case there was any resin that might make the clamps stick to the brackets. I removed the masking tape before the resin dried , no mess and no stuck masking tape.
