After completing the cuts for the aux tanks, I radiused the corners and smoothed the edges. Then I drilled out every other rivet along the edges of the cutout for the cover attachment screws.
Using 0.025" 2024-T3 aluminum, I fabricated two covers and drilled them to match the fastener holes in the wing.
Of course, I proved to myself the old sayings of "measure twice, cut once" and "read before you assemble" still held true. :(
Due to some very stupid mistakes, I made 3 sets of covers before they were correct and AFTER drilling out the existing rivets I read the builders manual where it suggested drilling new holes for the cover in BETWEEN the existing rivets.
I spent some time considering the possible ramifications of using the fastener holes as I had drilled them out versus reinstalling fasteners and drilling new holes for nutplates located in between the existing rivets. In the end, I could not see any structural reason why I could not continue as planned.
