Place a pin between the TE of the wing and the LE of the aileron. Put the pin through the CA hinge. That way you get the proper gap and at the same time you keep the CA hinge from sliding in to far on either the aileron or the wing. After you get it pinned and before you put any CA on flex the aileron full up and full down to help line the hinges and make sure there is no binding. Then put your CA on very carefully so it doesn't run all over the place. If you do get some runs clean immediately with Acetone. It won't hurt the covering and will clean the CA off.