Center section spar - part 12

Layup #6 prep (8.5 hrs)

I wasn’t looking forward to the clean up job, but I had hoped that switching from than the transparent tape to the gray one might help.

Spar-cap aftermath. Flox/epoxy overflow evident.

The identification of the trouble spots actually did get a lot more obvious, and using a chisel to break up the dried up flox over the tape worked great, then it was just a matter of peeling the tape off.

Chipping the flox off

Removing the flox overflow first, then the leftover duct tape.

Cleaning up

Sanding was still necessary, but since the overflow had already been dealt with, it went much faster this time around.

Sanding the spar-cap flush with the aft spar face

Spar-caps cleaned up

Next, I rounded the corners of both spar-caps where they meet the rear face of the spar…

Router used to round the edges

… as well as the corners of both LWA2s and LWA3s.

Machining the fillets on LWA3

These plates will later get floxed and glassed over the top of layup #6, in the same places where the internal plates were inserted previously.

Left LWA3 fit test

Four wooden blocks get inserted into the spar. These absorb the crush forces of the bolts that connect the engine mount extrusions to the spar. They are normally 1” wide, but since my fuselage is 2” wider, and I have not yet decided how I will deal with this area, I made the blocks oversize in order to have more flexibility later.

Oversize wood insert

Easiest way to remove the foam...

... and fastest.

Wood insert cutouts completed

Wood blok in need of shaping

Wood blocks shaped on the belt sander

I used flox to attach the wooden blocks to the spar.

Prepping for the wood blocks installation

Floxing the wood books to the spar

Wood blocks curing overnight

After curing and a light sanding, this spar will be ready for layup #6.