Fuel Tanks 1


	I've heard lots of talk about the tanks, some good, some bad. While I'm certainly not looking forward to working with the black goop, I'm not dreading it either. "Clean as you go" and us a syringe to squirt the stuff where it's suppose to go, and life should be good. For no particular reason, I decided to go with the flop tubes in both tanks. With this setup, I'll probably be able to fly through a whole tank of gas and not have to worry. The only limitation is the fact that I don't plan on using an inverted oil system. Hmmmmm......why am I doing things this way? To late. I'm also going to be using the capacitive fuel probes. I like the fact that there are no moving parts to break. I don't like the fact that, should there be a problem with a wire connection, I'm hosed (pun intended). Every option has it's drawbacks I suppose.
		These are the flop tubes that suck up the fuel. There are anodized fittings on the output ends and a big heavy brass weight with rubber O ring on the end where the fuel gets sucked up. It wasn't necessary, but I decided to put one in each tank. The hose is braided steel. The rubber O ring is presumably to keep from banging the weight on the skin and denting it. These pickup tubes are very nice and should "work fine, last long time".
		I followed the construction manual and started prepping the tank ribs. I drilled the vent holes in all tank ribs except the T-404 ribs. The inboard most tank rib is where the fuel pickup attaches and gets the most work. I'll prep those later. This picture shows me filing down the high spots that are formed at the factory when the flanges get bent. These high spots will translate to bump in the skin if not removed. Deburr and file, it's a never ending job when prepping all the ribs.
		Once again, I'm following the manual dutifully. I should have read the fine print that said, "for all you yahoo's that are installing inverted fuel pickup, look at the plans". I didn't look at the plans before cutting the all the holes in the inner tank ribs and paid the price. It seems that I don't want a hole in one of the ribs that has a ringed door on the bottom hole. Here is the patchwork that I put together to plug up the middle hole. No harm, no foul. Just about an extra 1/2 hour worth of work.
		When going inverted, this is the hinged door that will keep the fuel from leaving the innermost fuel bay where the fuel pickup is located but still allow fuel to flow to the pickup area during normal flight. This is also why you don't want the hole in the center of the rib as well. I made some small changes to this hinge from the plans. The angle at the top of the hinge does two things. First, it keeps the door from flopping all the way open and staying there. Second, it provides a spacer that allows the door to close flush with the rib. The plans showed the piano hinge sitting flush to the rib and this would not allow the door to close properly. The hinge pin will be positioned so it is kept from coming out by the rear tank baffle.