Section 28 Fuel System

This is quite a new ball game: back to school to learn plumbing which explains why, though I worked on this section for the last three weeks I did not have time to blog. Actually at the time I am writing this section 28 is over but I want to provide some highlights of the difficulties I faced for the other builders.
This is what's at stake:

 It's just two lines: the main fuel line and the fuel return line.
So, what's the catch?
Learning how to bend with the tube bender, learning how to flare with the tube flaring tool, learning the names of the fittings by identifying them on the drawings and digging into the parts drawers to find them...
First thing I did was research the VAF forum about this section. The results were not too encouraging. One guy started saying "first order an additional 6 ft of aluminum tube, you will need it". There are indeed many ways to waste the just enough aluminum tubing that comes with the fuselage kit, for example: do the flaring before inserting the fittings on the tube or inserting the flaring in the wrong direction, do the flaring before inserting the tube through the proper snap bushing, and more...

I started with Page 28-02:

My first challenge was the "pipe thread sealant" mention in step 1. OK, I know what a thread sealant is but in aviation there are often special requirements that force you to order online to aviation parts suppliers. My research led me to choose "Permatex with PTFE" because it works both on fuel and brake lines and it is available in local car parts stores. The fuel valve riveting was a bit challenging because it's not possible for one person to reach both sides of the bottom skin. I manage to block the valve in position with a 2X4 and was able to push the rivets in without pushing the valve out... after a few tries.
Then starts the real plumbing business with bending, flaring and all that jazz!

There is another challenge with the bending tool that came with the Avery tool kit: the radius of the bends does not fit the radius on the drawings. This is particularly a problem with the small 1/4" return fuel line. As a result the lengths of tubing indicated in the instructions are not adequate and need to be adjusted. Page 4 is quite a challenge because of the length of the pipe that has to be fed through the bulkhead and several bushings: this snake does not get tamed easily!

 

 After page 4, page 5 is a piece of cake... well with the exception of the AN 819 fitting that I inserted with its thread sealant before attaching the gascolator to the firewall: always read the instructions carefully

With Page 6, the return line is a tad easier to manage because of its smaller diameter of 1/4" but it's a long one and quite a bit of bending/unbending is required along the way.

 Now for the results of this long fight:
This is the arrival at the firewall with the fuel flow transducer in red

 The fuel valve

 The fuel pump

That's all folks for the fuel system... well, I still have to torque all the flared fittings and check for fuel leaks but before that I will have to build the fuel tank, oh noooo!
And by the way, I did not need to order more aluminum tubing: tada!