Work has been pretty all consuming the last few weeks, so I haven't had much time in the garage. I finally had some time to decompress tonight, so got a few things done though.
Just a random tool - I had no idea this existed until I heard someone mention it online. It's a chuck for my right angle pneumatic drill. The drill only takes threaded drill bits, which can make life difficult when you need a very specific size bit. Threaded bits aren't the easiest things to track down (when you just need one and not 50 of one size), so usually have to be special ordered and the shipping costs 10x what the bit does. This chuck is quite small and threads into the drill, but then can accept regular drill bits. Having this earlier in the build would have been a huge help.
The vent line fittings that protrude through the forward bottom fuselage skin need some protection from insects, so I prosealed a piece of screen over the external end. Once the proseal dries I'll trim the excess off.
Since I was mixing up a batch of proseal, I decided to also seal up the gap where the gear leg tower exits the fuselage. This area will be covered up with a fairing, so it's not visible, but it would allow an awful lot of cold air to sneak into the cabin if it were left open. The picture is deceptive - it's really a fairly thin line of proseal that will remain once the tape is pulled.
The instructions didn't mention this yet, but I decided to put the rudder cables in place. The reason being that the fuel vent line has to bend around the cable in one location, so I wanted the cable in place to make sure I gave enough room.
My first try at bending and flaring the soft aluminum vent lines was laughable. The tubing Van's uses is very soft, making it easy to shape, but because of that, it's also really tough to create straight runs. It doesn't help that it ships coiled up to begin with. After a few failures, I relearned how to make acceptable flares (note to self - for 1/4" soft aluminum tubing, it's 4.25 turns of the flaring die after first contact - that makes a flare that is in the middle of the .34-.36" flare diameter range). The first vent line run comes in through the side skin from the wing root and turns forward. It passes through the vertical bulkhead using an elbow fitting.
This elbow fitting was a nightmare to get in place. A 30 second job of screwing on the nut on the back side was really a 2 hour bout of frustration and red neck tool making. The vertical bulkhead has a lip that curls around the back, and no wrench or socket can get at the nut. I finally had to chop down an old wrench so it was only about 2 inches long and grind the sides away until it would fit in place. I couldn't get any leverage to really torque the nut down much, but it's as good as it can be. I'll put some proseal or loctite on the nut just to keep it from backing off due to vibration.
The big bear for the vent line was the forward portion that runs from the elbow fitting, up and around the rudder cable, up to the longeron (so it's above the level of the fuel tank) and back down to exit at the floor. The bends were bad enough to just get in the right place, but then they are also all in different planes from each other. For example, in the picture it looks like the top portion starts with a 45 degree angle off of the vertical and just runs forward then back down. In reality, it comes off the 45, then straight forward, then dives inward a couple of inches under the top firewall bracket, the it takes a sharp curve down and back to the outside, then straight down before it finally goes back towards the centerline and out the bottom. I'm not embarrassed to say this was attempt number 2! I got the first one nearly completely done, then on the last 90 degree bend to the floor fitting, I crimped the tubing. I have a tubing bender that makes very nice bends, but I couldn't use it (or even the spring benders) on that last bend because there is only about 1" of length. The nut and sleeve have to go on before flaring of course, and when they're on, the length is so short that none of the bending tools can be used without hitting the nut. Fingers don't make very easy 90 degree bends. My second attempt worked out well enough to call it done though. Tomorrow I'll tackle the right side, which I'm guessing will go much quicker.
