The countersinking and dimpling work continues. I started by countersinking all of of the Z-brackets to allow flush rivets to later be installed for nutplates. Afterwards, I used scotchbrite pads to roughen up the surfaces of those Z-brackets. Next was to cut apart the 4 shims that came as one piece, clecoing them to the tank attach brackets, and marking where they had to be trimmed. I then went over to the belt sander and bench grinder to cut and smooth them to final dimensions. Those shims then had to be dimpled with the squeezer to allow nutplates to later be attached. Then the flanges of the tank attach brackets had to be countersunk to allow the dimpled tank skins to eventually be attached. I found it easiest to clamp these attach brackets to the side of my worktable so that I could use my drill vertically down into the flange. Next was moving the tank skins from the garage and into my workarea and removing the blue vinyl from the inside surfaces. I ended up using a Dremel with a cutoff wheel to cut the strips from the edges of the tank skins, since those strips would be needed for the leading edge wing section. What's next? Time to matchdrill the J-channel and other final prep steps before the glueing starts.