Fuel Tank Fit

[Concorde]

Quick question. Fuel tank straps that I received with my kit were all the same length , I thought the back straps were supposed to be longer .
Sorry, didn’t mean to change the subject !

[Area 51%]

While trying to deal with the plastic tank fitment issues I had, Kerry approved warming the tank with a heat gun and reshaping. That might be a better solution than changing the profile of the firewall stiffener.

According to the plans, the tank straps are the same, but they show a longer bolt in the back to make up the difference.

[racaldwell]

Small gap at stiffener

I installed the front strap and by tightening it very tight I was able to get about 1/32" gap between the tank and firewall stiffener.

But, since the tank is not symmetrical, the right side of the tank pushes up the glareshield and there is a gap on the left side of the crosstie.

Crosstie gap

I installed the oops fittings but did a crappy job of it. I tried to get the mound of plastic off the inside using a dremel wheel & stone. On one I made a small groove where the o-ring would sit. But worse, the fitting on the side as right in the corner of the tank and the fitting would not fit. Working at it with a dremel stone I worked the plastic back inside the corner but in the process the 9/16" hole became 5/8". The o-ring was right on the edge of the hole. My fix was to make two aluminum sheets that fit inside the tank and use Fuel tank sealant from Van's Aircraft to seal between the plastic and aluminum sheets and also seal the holes around the oops fittings. This worked.

Oops fittings sealed

Pressure tested and it held pressure over the weekend. I call it done. Enough with this fuel tank.

Pressure test

Rick Caldwell
Xenos 0057

[Rick524]

Hi Rick, I remember having a strip of felt between the crosstie and tank. A full tank weighs just over 100 Lbs
so the tank will deform a little when full and rest flat on the felt. I wouldn't worry about one side being a bit
high when empty. I would try and get some space between the stiffener and tank though. Maybe the felt will help
there too.


Rick
C-GRIX

[racaldwell]

That's a good idea, Rick. I'll double up a little patch of felt on the firewall stiffener. I have UHMW tape on the crosstie now but I think it is a good idea to put a layer of felt there, too.

Rick C.