Tonight, I deburred the holes in the wing skin where it rivets to the flap brace, then dimpled the holes using the pneumatic squeezer. Used a deburr bit in a cordless screwdriver to c/s the wing skin where the two keeper rivets had been lpreviously removed. I clamped the flap brace to a piece of oak plank and drilled thru the holes into the oak. I inserted clecoes thru the brace into the oak to keep the pilot of the c/s from wandering while I machine countersunk the brace. Clecoed the brace and wing hinge back onto the wing to check fit. The dimpled skin fit smoothly into the countersunk flap brace.
