Forward-fuselage bulkheads and bottom skin progress

Forward + aft portions of the fuselage attached together for drilling

I measured the wing spar at exactly 1.7" thick. When I first attached the center spars with spacers, I instead measured it at close to 1.8":

Spacers measured around 1.8" (should be 1.7")

Turns out that the thickness of the blue vynil adds up quickly, and 28 layers of it per set of spacers wasn't helping. I removed it and deburred the parts for some extra smooth coupling:

Spacers with all the blue vinyl removed

That got me almost all the way there (about .02" to go):

Spacers much closer to 1.7"

Since the spacers were slightly curved, I just applied force to make them flat. I could have torqued the nuts, but I don't have a torque wrench that can do the required 1100in-lbs (will order one for when I need to attach these semi-permanently until the wings are actually attached), so I instead just squeezed them with clamps - first with my usual plastic clamps, which did pretty much nothing:

First attempt at compressing spacers, using regular clamps

Then I used the heavy-duty clamps with some felt padding (idea credit goes to the wife):

Successfully compressed spacers with heavy-duty clamps

and with that, holes were magically aligned :) so I final-drilled all of those, and started deburring some of them.

Time lapse:

Total forward-fuselage bulkheads, ribs and bottom skins rivets: 0
Total forward-fuselage bulkheads, ribs and bottom skins time: 44.4h