Before riveting the bottom skins there were some tasks to finish first.
I was concerned that the transition from the stringer and rib 9 caused a dent in the bottom skin. As I saw on other builder blogs I trimmed the stringer and a small piece of the rib flange:
The edge distance of the hole for the grommet wasn’t that much and since I want to use shielded cable for the landing and taxi lights (which is thicker) I needed to enlarge the hole. That would compromise the edge distance even more. I designed 2 small brackets and checked with TAF if this change is approved; which it was.
2 new brackets from 6061-T6 0.025″ / 0.64mm thick:
Extra holes in rib 9:
Ready:
The rivet line skin 1 vs. main spar where the tank will be attached had slightly misaligned holes, after consulting TAF I reamed the holes with a small file and finally with a reamer:
TAF moved in general from M3 to M4 rivnuts. I ordered them online, reamed the holes from the larger inspection panels to 6 mm and inserted them with Loctite 277:
1 rivnut conflicted with a flange of rib 8 which I trimmed to make it fit:
Good fit now:
The 3 bottom skins are now ready to rivet:
