I installed the nutplates on the main fuel tank access panel. I used K1100-06 nutplates for everything but the corners, where I used K2000-06 one lug nut plates. I dimpled the rib #6 screw holes as the material was thinner, and used Avipro's method for the front and aft screw holes; namely, drill out the screw holes to a #8 drill after using the dimple guide to define where the nutplate goes, and following that by a healthy amount of 3/32 inch countersinking to allow room for the dimpled panel. I dimpled the #40 nutplate rivet holes. By the way, www.vansaircraft.com sells the K1100-06 nuplates for $0.58 a piece vs. $1.95 from AC Spruce.
