With the right tank mounted and clamped in place yesterday, the rivet hole locations were marked, and two test holes were drilled and clecoed on the top and bottom of the tank to verify correct hole positioning relative to the spar flanges.
By looking in the inboard end of the wing, behind the fuel tank, I was able to see the four cleco tips and verify that they were well positioned. With my confidence bolstered, the remaining rivet holes were drilled without any issues.
The green masking tape covers the gap between the tank skin and the aft skin to prevent chips from falling into the wing while drilling the upper row of holes. The white paper dots are removable Avery labels used to prevent me from drilling the wrong holes.
