Center section spar - part 7

Closing the box (7.0 hrs)

Before I closed of the center-section spar by microing a lid over the top of it, there was still one thing I needed to do. 

You see, the spar has additional ancillary functions beside connecting wings, fuselage, and engine together. It doubles as storage compartment, and as an avenue for fuselage wiring to reach the far end of the wings. This last function is what I'll address.

I will be able to drill entry and exit holes into the spar at any time during construction, but what will be hard to do later on is cutting holes through the inner bulkheads. Such task is nearly trivial at this stage, so I took care of it now.

Opening up a hole into CS7 inner bulkhead for wiring

I used a 1" (2.5 cm) spade

Same thing happening to CS6

The edges of this hole are pretty sharp

I worried about the wires chafing on the glass edges

I chose to do a flox corner to provide better wiring support. I started by removing the foam.

Those holes were tough to get to, so I improvised this foam removing tool made out of folded sandpaper.

The idea was to remove foam and micro from the inner walls of the bulkhead

This little tool worked flawlessly

I filled the gaps with flox, then made a small flox ramp in front of the holes.

The idea was for the ramp to help guide the wires straight into the hole later on.

This is the ramp after curing and a little sanding

I fed a few wires along the back wall, and all easily found their way into the hole. Perfect!

With this small but important task accomplished, it was time to close the lid to this box.

I marked the bulkhead location on the inside of the lid

Then sanded the glass rough.

Running very low on micro-balloons, I opted for another flox corner on the bulkheads.

Good thing I did, because the last few joints had to get micro mixed with flox.

Flox corner on CS7 ready to go

Same thing on CS6

Using up the last of my micro (I really thought I had another bag of it somewhere!)

I used nails to prevent the lids from sliding overnight

Nails, I had a lot of, more micro is what I needed.

Last time anyone will ever see CS7...

... and CS6

That is actually micro/flox mix

At this point I just wanted to get it done.

There you go... done!

This box will have to sit a few days for the micro to dry, before getting out of the jig.

Getting some help from gravity

Just about all the heavy thing I could find got to ride the spar

Finally, there she is! Out of the jig for the first time. Her daddy is so proud ;-)