Removed sealant from inside forward corners of tank. (step 7)
Test fit doublers inside tank, then clecoed to front face of tank bracket. Match drilled holes through inboard and outboard doublers common to tank bracket and tank bulkhead. Used an electrical box blank cover as 1/8" spacer for drilling upper hole in inboard doubler. Removed inboard doubler and reclecoed to inside of tank. (steps 8 and 9)
Final drilled #19 holes in inboard doubler where screws will be installed. (step 10)
Machine countersunk lower screw hole in tank bracket for head of countersunk screw. (step 11)
Removed doublers and deburred. (step 12 - partial)
During removal of the top tank skin yesterday, I broke the return line clips so fabricated new ones.
Spent the rest of the day scraping off sealant and removing remnants with MEK. Still have the inside flange of the top tank skin to do. Once done, tank is ready to go back together and sealed.