I finally got started on the wings today. Section 13.
Most of the previous sections started with something mundane like cutting apart and deburring a couple of parts. Not Section 13! No, it has you cut some raw j-channel, bolt it to your (expensive!) spars, and then drill away! The instructions are pretty clear, but I must have read through them a dozen times trying to make sense of it. It is easier with the spar and j-channel in front of you. I measured several times to get the right length. Be sure to cut the large stiffeners from the 8′ sections and the small stiffeners from the 6′ sections. A couple builders cut the small ones from the 8′ ones and had to order new angle. Not expensive, but time consuming. So, the upshot is that you cut two long pieces (for each spar) and two short pieces. The total length is a bit more than the length of the spar (not an issue, these parts don’t really go here, you are just using your spar as a very expensive hole spacer). The overlap is in the middle. I used clamp cleco’s to hold the angle in place. You need to ensure that the j-channel stands 1/16″ proud of the spar edge. A real pain.
The illustration doesn’t depict the overlap very well and I didn’t find another builder log with good pictures. It looks like this:
On the bottom edge, the overlap occurs where you aren’t supposed to drill anyway. On the top, I did the large piece, unclamped it, and then did the small piece. It seemed easier and more consistent than trying to manage the nested parts.
Here’s the top edge of the left spar. You can see the gap where the nut plates go and you don’t drill. Be careful to note that the DO NOT DRILL section includes one hole BEYOND the nut plate. I would drill a couple holes and add a cleco. Drill a couple more and add another one. It was monotinous! And the compressor was running a lot because the drill uses a lot of air (much more than the rivet gun) (and because I have a small leak in the connection).
In the end, you get 4 parts. These have to be labeled carefully because top and bottom look very similar. And there will be a left and right version of each (when I finish the next spar). This is the left W 00009A upper stiffener.
You pull the stiffeners off and set them aside (used in a later section) and then drill the remaining #40 holes. That went really fast and didn’t use nearly as much air as the match drilling
Next week: The same thing with the right spar!