Last in the series of bulkheads is the F-712 bulkhead.
The function of this bulkhead is to support the tailwheel fork structure and to hold the rear spar of the vertical stabilisor.
This bulkhead forms the lowest point of your plane.
This is probably the most simple of all the bulkheads for now. Deburring of the edges and notches.
Then clamp both parts back to back and backdrill all the 3/32 holes with the #40 reamer.
My golden rule these days is: if the holes are prepunched, always ream ! never drill. The hole is much nicer and precise with a reamer
To keep all well aligned, I also used some #12 clecoes in the tooling holes.
The parts will be rivetted with AN426-AD3 rivets. The flush side needs to be on the back part (F-712B). The reason for this is that the rear spar of the vertical stabilisor will lay flush against this bulkhead. Pay special attention before you start that you have the dimples on the right side.
All done.
Next, I will do some more work on preparing the firewall. My fellow builders tell me to do a lot of the placement work on the firewall upfront because drilling in the steel plate is much easier if you can still lay the plate down on a workbench. It all becomes much more difficult once the firewall is installed on the fuselage. Also, some rivet holes need to be drilled out to #12 and it's much better to do this now before all stiffeners are rivetted on (chips getting lost between stiffener and firewall, steel chip choqueing in between. All very hard to solve once it's all rivetted)
More on that later.