Today I started the first 'real work' on the wing kit after receiving news that my spar is just fine (see update on yesterday's page). So I began by running the drill (#40 and #19) through all the nutplate holes for the tank attach on the spars. There's a total of 120 nutplates, or 120 #19 holes, and 240 #40 holes. I drilled them all out and then began all the countersinking of those holes. I got all the #40's countersunk, and got about 15 or so of the big ones, and decided to call it a night. You can see in the pic below the method I used to keep the big countersink centered, as it has to go deep enough to go all the way through the spar, and thus lose it's alignment hole near the end. It's quite similar to the method used by Dan Checkoway, as I got started and realized what I had read before would probably be as easy and good as it gets. I did differ slightly as I used a thick aluminum sheet for alignment, and another dimpled piece of scrap to confirm proper depth to ensure a flush tank skin. Scott suggested putting the spars on the jig upside down to do the countersinking and this has worked out quite well, as it's just the right height to work on.
Here you can see how far I got with the big countersinks today. I should be able to finish it up with about another hour or so of work tomorrow. Then I'll alodine the exposed aluminum with a q-tip and rivet in the nutplates.
