So, I have an issue. When I had the tank all clecoed together and mounted on the main spar for a test fit, I noticed I had a full 1/16" gap between the tank skin and the top main wing skin. I have studied this problem and it has me stumped. I noticed that my tank rib flanges were not square and were bent out a bit. This maybe would bow the tank skin outward, pulling the tank skin edge away from the main skin. So, I reworked all the tank ribs and adjusted the flanges to 90 degrees. I'll move ahead and hope for the best.
I then did the final tank rib scrub with a scotch bright pad. The flanges were done before I dimpled so all I had to do was the web.
Image 2 shows the drilling of the holes for the flop tube guards. The outside web is counter sunk like all thh other rivets in this area.
Image 3 shows these 2 square plates that I'm going to use to cover that center rib hole. The plan don't say to do it but I saw a builder log that showed an email from Vans that said to cover those holes. Still have not decided so the patches are made but not drilled or riveted. Covering the holes keeps gas from flowing out of the first tank bay during aerobatics.
