Today I scuffed, cleaned, and primed the faying surfaces on both sides of the seat pans in preparation for riveting the seat back hinges to the pans (photo 1).
While the primer was curing I laid out, drilled, and deburred the lightening holes in the F-638 seat back braces (photo 2).
To finish up, I clecoed the seat bottom hinges to the seat pans and match drilled the holes at the intersection of the aft hinge and floor ribs (photo 3). I then deburred and re-clecoed the aft hinge in preparation for riveting the hinges. It was to late to rivet, so I hope to do that tomorrow.