It's not the aileron that's the problem--the torque rod is sitting high. The only way I can reduce the gap is to build up the back of the wing a bit, around the torque rod.

This is my first balsa bird with ailerons, and I've learned an important lesson. Next time I will recess the Torque rod a bit. Didn't have the experience.

But what about the concern with the CA properly coating the hinges if I add a 1/16: strip where the aileron will fit onto the wing? Will the CA wick in properly, even if I drill a hole down the center of the hinge slot?