Total Hours: 1119.2 hours
Fwd ribs, Bulkheads, & bottom skins: 66.7 hours
This was section 28 in the plans. It felt like I would never finish this section. Most notably in this section the forward and mid sections of the fuse are joined. I was going to use hardware store bolts to join the spars, but in the end decided to use the close tolerance bolts provided in the kit. I felt this would better insure I had proper alignment between the sections. The worry is that there may be trouble removing them when the time comes to join the wings and the bolts get damaged. I don’t think this is worth the concern. If the cadmium coating of the bolts is entirely scraped off, I’ll replace the bolts when it’s time for the wings. But I doubt that will be necessary. I only torqued the smaller bolts (AN6) , leaving the larger ones (AN9) in place to help with alignment but without nuts. And I will definitely use fresh nuts on the smaller bolts when I join the wings.
I did have a few relatively minor issues during this section which added up to a whole lot of extra time. One was having to drill out a bunch of rivets to allow clearance for the front floors. In the process I damaged one hole really good which will now require a 5/32 rivet. Another issue was when riveting the firewall to one of the forward skins. Somehow the dimple in the rib cracked. In a very tight spot I managed to polish out the whole cracked dimple and install a doubler plate. Here’s a few pics of the repair, which required a 5/32 rivet. (I have a supply of AN426AD5-12 rivets which I can cut to size).
The last issue I dealt with took the most time to figure out. The plans have you install the gear mounts with just a few bolts in order to get a bunch of holes matched to the mounts. No problem on the right side, but the left would simply not go in. There was no way I could get the bolts all in. Somehow, it seemed that the alignment (which seemed perfect when I matched them to the spar) was off. In the end I realized that the mount was slightly warped (just a little curve to it). When I matched it to the spar, it was clamped down tightly to the spar which caused the curve to flatten out (as it should). But now as I try to install it, there are no clamps and the holes don’t align. After many, many, many hours of thinking and trying lots of things, I came upon the solution. I mounted an AN3 bolt to my drill press and used it like a lathe. I then filed out the threads of the bolt entirely and brought the end to a point. I then used a scotch-brite wheel to round out the tip. I used this as a guide pin to get the mount into alignment. I positioned the mount so that one hole was aligned and put in a bolt. Then I used my guide pin (oiled up real good) to force alignment with another hole. This allowed me to insert a second bolt. When I removed the alignment pin, all the holes were aligned and I could finally proceed with the task. This all took a good 8 hours to figure out and get working. Next time something like this comes up, it’s not going to take so long.
