Spar Prep Page 13-3 steps 3-5

5:00 hrs Today/ 366:30 hrs Total Project
Page 13-3 steps 1-2

Today unexpectedly became a marathon day. Russ stopped by to help and I put him to work doing the #40 skin countersinks. I went to work riveting the nutplates for the fuel tanks. There are a lot of these. Then I had to countersink for the #8 screws. I started with a #30 countersink like it said and thought to myself “this will not work”. I actually rummaged around the shop to see if I could find something better and came up empty. I decided to try it again. I then read in the instructions the maximum diameter on the outside edge of the countersink was 3/8 inch. I measured my holes and I was not even close to that. I countersunk away…a little deeper…and a little deeper. When I got close to 3/8 of an inch, everything seemed to fall into place perfectly and my holes looked great! This made doing the other counter-sunk holes for the nutplates easy as long as I don’t change the cage any. 

This process and both of us countersinking made a mess. I actually vacuumed the shop not once but twice today to get the aluminum debris up. I hate working in a dirty environment! Before the day was up, I managed to get the top of both spars complete. Next week it will be to get the bottom flange complete.




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