This session started by final-drilling #40 the remaining .094 holes and the nutplate attach holes in the upper and lower flanges of the Left Main Spar Assembly. Additionally, there are four nutplate attach holes in the tip of the Left Main Spar and three at the root the need to be final drilled to #40.
These are the four in the tip.....
And these are the three in the root.....
Since these holes are already pre-punched from Van’s, I used a #40 reamer to final-drill.
Now on to COUNTERSINKING! The plans caution you to only countersink deep enough to fit the head of a AN426AD3 rivet. First, the nutplate attach holes on the Main Spar Flanges get countersunk #40. Secondly, the nutplate attach holes in the web tip and root get countersunk #40. And lastly, the 14 holes for the Wing Ribs get countersunk #40. Here are a few pictures after all the holes are countersunk. I put the orange tape on to cover the gap between the Main Spar and Flange to keep metal shavings from getting in the crack.
Outboard Main Spar Web.....
Inboard Main Spar Web.....
Alright, according to the plans I need to install the Fuel Tank Skin attach nutplates to the Left Main Spar. However, I would like to prime the Left Main Spar first. So, we will move on to preparing the Right Main Spar up to this point and I will prime them together at the same time.
I started the Right Main Spar the same way I did the Left.....by labeling the correct orientation of the Spar.
Now we have to cut four (two each side) Wing Box J-Channels for the Right Main Spar. This picture shows two already cut to length (clamped on the Right Spar Flange) and the remaining J-Channel.
