1 Feb 2026 - 4.5 hours

I started out another cold day by finishing up the dimpling of the rear spars. The fit with the squeezer yoke was ever so slightly tight with the angle on the bottom of the rear spar being greater than 90, so I filed off a bit of the nose of the yoke and it fit much better. Then I hit the dimples with two turns of the countersink to make the skins nest better.

Next, I moved onto countersinking the main spar. Since I have removed all the nutplates and their rivets, I took the opportunity to freshen up the nutplate rivet countersinks and make sure they were all deep enough...When drilling them out, I noticed a few were sitting a little proud of the surface so I took care of that.

The next three-ish hours was spent doing a huge amount of countersinks on the main spar. The material is too thick to get dimpled, and the skins have flush rivets in dimples, so the only option is to countersink literally hundreds of holes. I did 7 clicks on the countersink cage past flush (as called out in the build manual) for a countersink that will receive a dimpled skin and then just put my head down and worked. (Don't let the open garage fool you, it was only 29 today, but the concrete floor in the garage is much colder than that so it was making the garage colder than outside so I opened up the door to let the "warmth" in)

Here you can see some circled holes that are countersunk for a rivet rather than a dimpled skin. The top most hole of the main ribs that sit behind the tanks will be under the tank skin but not connected with a screw so those will just get a flush rivet through the spar and into the rib. I made sure to mark those so I didn't countersink them too deep with the rest of the holes on the spars.

Feels good to have this monotony behind me. Next I will need to hit all those countersinks with primer, then I can squeeze the previously mentioned top rib-to-spar rivets and also reinstall the correct spar nutplates.