The earlier part of the day was consumed with playing around with the assembly order of the spar box and associated ribs to accommodate as many solid rivets as possible. The details have been, for the most part, determined taking into consideration simplicity and rivet accessibility based on the inventory of squeezers and yokes at the shop. I may even pound a few rivets at a couple of locations where the ribs meet the spar and the rivet squeezers can’t get on the rivet squarely. Since the spar material is .040 inch, it will hold up just fine to a little rivet gun & bucking bar persuasion. Also need to dimple both the front and rear spars … waited on this because once dimpled, it will be tricky to get the assembly together yet alone apart.
After disassembling the spar box for about the
fourth (and hopefully last) time it was time to begin attaching hardware to the
spars. The holes for nutplates and doubler plates were drilled in a previous
session and countersunk for flush rivets … although I discovered I forgot to
countersink the holes for four nutplates on the front spar and because it was
getting late, did not get all the nutplates finished.
Squeezing the flush rivets that attach the
nutplates and doubler to the front spar using the pneumatic squeezer.
Front spar’s nutplates & doublers finished
rivets and the rear spar’s finished nutplate rivets shown from the outside of
the spar where the rivets are flush. One can also see the nutplate holes that
need to get finished tomorrow after countersinking the outside of the spar for
the flush rivets.