The shop session today began with completing the rivets on the cockpit rails. Once the rails were finished the seatback support plates were riveted in place. While there were only 11 rivets in each plate it was a challenge and took considerable time. Again, the problem was getting my hand with a bucking bar up behind the plate and holding it firmly. In any event, I eventually got all the rivets driven with the exception of the two at the extreme top. I just couldn't reach them and hold the bar so I opted for some structural blind rivets.
Once the plates were installed, the seatback weldment was riveted, screwed, and bolted in place to the cockpit rails and support plate. I deviated a little from the plans at this point. First, the rivet call out was for three CS4-4 blind rivets to be installed in the vicinity of the bars on the weldment. I chose to use four CS4-4 rivets, two at each bar. You can see them in image 2 below. Bucking these four rivets was problematic at best.
I also chose to substitute a number 4 solid rivet for the aft most screw attaching the seatback weldment to the cockpit rail and spacer. This was done to avoid an edge clearance issue that would have resulted by countersinking and dimpling for the number 8 screw called out in the plans.
