Brief Description: Screws & Platenuts for the forward access panels
I measured, spanned, marked, and drilled screw holes into the two doublers. I wanted about 1 1/4" spacing for flat-head #8 screws. Once I drilled pilot holes to #40, I cleco'd the doublers to the skin, then positioned the access panels in place on the doublers and match-drilled the screw holes into the doubler.
After deburring all holes, I final-drilled the access panel holes for #8 screws and dimpled them. I primed the doublers, then riveted K1000-8 nutplates to the doublers after final-drilling those screw holes.