Drilled and countersunk the trailing edges of both ailerons. Prepped for proseal. I also match drilled through the steel counterbalance arm. Hole alignment was a tiny bit off because the drill walked a little but during first part of drilling, I used a brand new bit and they still had same issue. I went slower at first and the rest turned out fine. I drilled perpeidicular to hole. I then deburred the outside and inside of all holes. Primed the counterbalance.
countersinking aileron trailing edge
aileron leading edge dimpled prepped for final assemply
CB all secured not need to remove prime and final rivet