Wing Bushing Installation

by Todd W. Ashcraft

I've come up with a pretty clean way to epoxy the wing bushings in the spar with the wing/fuselage upright (my garage is too small to tip the whole deal on its nose). Sit the wing slightly nose-up (on sawhorses/etc.) Put in the bushings. Lower the fuselage into place, and rig/check the aliignment (I used a digital level alot). With the drop links installed, put in the pins through the gussets/bushings and tighten. Make "dams" out of roof flashing and tape around the bushings at the front and rear face of the spar using packing tape. The tighter the tape job, the less clean-up work later. At the top of the bushing holes in the wood (on the front face of the spar), punch a hole in the flashing to inject the resin. Using a syringe for horses (from a farm supply?) inject un-thickened West epoxy SLOWLY into the gap around each bushing. You can nearly fill the gap this way. Once the resin is cured, pull off the fuselage, tear off the tape and flashing (I didn't need to wax the aluminum) and tip the wing nose down. Rough-up the cured epoxy in the air gaps left at the top of the bushings/holes and pour in more resin. By roughing-up the cured resin first, you mechanically key the new stuff to the old. I had good luck (only minor drips past the dams) with this method, and it allows you to fuss over the alignment during the pot/work-life of the epoxy. HOWEVER, NOTHING BEATS DOING THE JOB PER PRINT IF YOU CAN!