Used the edge distance marks to align the gussets and clamped in place. Drilled gusset and cleco'd as I went. Holes are close together and had to remove some cleco's to finish drilling all holes. Had to use the angle drill on a couple of holes close to firewall. Removed gussets and deburred holes on parts and longerons and firewall angle.
Bent the F-721B tab to match the inside of F-721A and drilled the junction of F-721A and F-721B by sliding a wood block inside the 721A and clamping in place. Removed the F-721A and B and deburred all holes, scuffed with scotchbrite and dimpled.
Ran a reamer through all 721A and B holes in longeron, then countersunk holes .007 deep for dimples.
Washed parts in warm water and Dawn dish soap and set out to dry.
