With the firewall done, it was time to begin building the bulkheads that will shape the fuselage. The biggest one of these is the center section bulkhead, which is also the frame that the wings will bolt into. It is made of to thick spars, much like the wing spars. The wing spars will then slide in between these spars and get bolted on.
Here are most of the parts for the center section bulkhead.
The first to do was to enlarge a bunch of holes for snapbushings that will hold things like fuel lines, wiring and rudder control wires.
Next I matchdrilled these side braces to the bulkhead main spars.
As you can see, I inserted the close tolerance wing bolts, to ensure the braces were in the exact location before matchdrilling.
I also had to matchdrill the rivet holes of these spacer bars to the forward bulkhead main spar.
This is where they will be installed.
Next I cut these two stiffeners that will also go on the forward bulkhead spar.
Matchdrilled them to the spar…
I also matchdrilled these support ribs and countersank for nutplate rivets.
After some more matchdrilling, deburring and countersinking, these parts are ready for primer or alodine. (I plan to just touch up the parts that are already alodine treated with alodine.)