Brief Description: Countersink Rivet Holes for Nutplates
I created a small doubler plate out of 1/8" Aluminum, clecoed it to one of the spars and then drilled out two rivet holes for one nutplate. I then used one #40 cleco in one of the holes and two side grip clecoes to hold the doubler in firmly in place while I countersunk the other nutplate rivet hole. The doubler plate was needed so the pilot on the countersink bit would have enough material to use as a guide to keep the countersink bit centered. This worked very well. Just a bit tedious with so many nutplates on the 4 different flanges. The countersink bit became quite hot! These nutplates will eventually be used to secure the fuel tanks. Aren't these Pre-Fab Spars beautiful?
