Chapter 24/25 – Aft fuselage seam

Today was all about dialing in the shape on the aft fuselage at the junction with the bottom cowling, with almost the entire focal point being on the vertical sidewall.

I spent about 45 minutes per side sanding down and contouring the West 410 filler that I applied last night.

As I continuously note, this is definitely an iterative process.  I then sanded down the other side as well.

I also sanded down the interfacing areas on the side front edges of the bottom cowling as well.  I then worked both the bottom cowling “micro” fill and the aft fuselage “micro” fill together.

As I then did on the other side as well.

A point of note I’ll make about filling in the depression at this side wall area on each side, is that I wish I had had the foresight to recognize the real need for it and do it earlier (i.e. pre- armpit intake install) as it is clearly closing the gap between the fuselage/cowling sidewall and the armpit intake vertical side.  Where Mike Melvill’s cowling installation instructions say to mount the armpit intakes 3/4″ from the bottom of the strake on the horizontal side, and 3/4″ from the sidewall on the vertical edge, my gap now will be just over 1/2″ on the sidewall side… more like 9/16″ really.

However, do I think this will lessen the effectiveness or hamper the air entering smoothly into the armpit intake scoop?  No.  Especially since I don’t have external fuel sump blisters to disturb the air in any way before the air enters the armpit intakes.  This is  just a symmetrical, cosmetic issue really, but one I wanted to address.

There is still some filling and matching left to do… as there always seems to be.  I’d say I’m about 90% done on this filling task.  I did do another round of minor straight West 410 fill… which I didn’t grab any pics of.  I then left that to cure overnight.

I then got busy sanding down the inside bottom surfaces of the main gear.  The left gear leg is shown here.  I did the same on the right side.

I had pondered about slathering up these bottom surfaces with micro, but then decided to wait until the gear fairing at the intersection between the top of the gear and fuselage are completed and installed… then I’ll finish the inside bottom surface of the gear legs all in one fell swoop.

Tomorrow I plan on epoxy-wiping the bottom of the wings with 5 coats of raw West epoxy (“raw” as in only epoxy + hardener…. to be clear, not just resin) among other tasks, if possible.

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