Wednesday, October 31, 2018

Section 10 - Aft. Fuselage (bulkheads; tie-down bracket priming)

Continued working on parts of the aft fuselage, including the rudder stops, horizontal stabilizer attach bar, rear bulkheads, and town-down bracket.  Since I fabricated/deburred the alclad parts enough to scratch them substantially, I decided to prime those with the non-alclad parts.

Countersunk rudder stops.  The regular countersink cage tool didn't fit due to the flange, so I used a countersink bit-extender (without a cage) and tried to carefully keep an even countersink:



\Primed rudder stops and horizontal stabilizer attach bar:


Oops - those edges are sharp (I hadn't deburred the edges of the bulkheads yet, and sliced my finger on one of them). I'm officially building an airplane now!


I forgot to take a picture when the bulkheads and tie down bracket were attached to the vertical stabilizer for match-drilling, but here is the end result.  Who has a 17/64" drill bit required for one of those holes?  Turns out, I had one that's about 20 years old.


... and the same for the extra holes in the vert. stabilizer:


Deburred bulkhead edges and holes; dimpled bulkheads; countersunk tie-down bracket; prepped and primed all three parts.  Note - there was an error in the plans which called for dimpling of two holes that exist partially behind the tie-down bracket.  I guess it is because those are part of the taildragger version of the plans, but were not removed in the tri-gear plans.  Of course, I dimpled them, and then when I tried to fit the tie-down bracket, they prevented the bracket from sitting flush.  No worries - I just used a double-flat set and squeezed both of them flat again (on both bulkheads).  Once primed it is difficult to tell which holes were re-flattened (not that it matters - these parts are not visible on the completed aircraft).





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