Got the remaining bulkhead parts prepped and primed. Split time with Sec 26 parts. After much consternation, I have settled on my rules for priming: - everything center bulkhead and forward will be Ekopoxy - anything potentially awkward to topcoat with interior paint will be Ekopoxy - tunnel interior will be Ekopoxy - all else is Ekoprime Based on those rules I used Ecopoxy for the bulkhead uprights. 3/4: riveted the rear fuselage bulkhead assembly together with the squeezer. Then riveted the rear spars to the rear spar bulkhead. Tried using the DRDT2 to set the -4 rivets in the rear spar. Worked out but you really have to be careful to keep it level or the rivets would clear over. Got the hang of it and only drilled out a couple. Worked out, but in hindsight I could have just bucked them all.