All my airplanes hinges are pinned (steel seamstress type pins), one on each side of the hinge, after the airplane has been covered, painted, etc. I cut the pin just short of the thickness of the surfaces, push them from the bottom with the end of an Xacto knife, a drop of Ca. and that's it.! The only airplane that the aileron came loose was an ARF that didn't have them and after inserting them, no more problems.