After the nutplates were on, I had to go back and CSK all the fuel tank and access panel screw holes. I had some indecision on which #30 CSK to use as I have more than one (3/8 and 1/2). I ended up going with the 3/8’s and it worked fine—double checked the first one against the max diameter measurements called out in the plans and using a #19 and #27 dimpled piece of .032 as a access plate/fuel tank skin test sample. I then Sanchemed all the CSKs as I had down the nutplate rivet holes earlier.
