Didn't do much tonight...just dimpled the aft edge of the left wing bottom skins where the flap brace attaches.

I also machine countersunk the matching holes on the flap brace. My countersink tool is getting dull (probably from when I countersunk some steel nutplates), so I had to run a scotchbright pad along the flange to deburr the countersinks. I'll touch up the primer tomorrow.