Wing tank help?

[1938BF50]

What have you all done for covering the area around the wing tank gas cap? Notice that the straightedge is laying across the tops of the adjacent ribs....the cap is setting nearly 1/2" low. How is this adressed in covering the wing?

Mike

[mikeg]

Re: Wing tank help?

I have always glued a 1/4" plywood ring to the top of the tank to glue the fabric to. Has always worked for me.
Mikeg

[Ragwing nut]

Re: Wing tank help?

There is a metal ring that goes on before you cover that is flanged and has holes in the perimeter to glue fabric to. sorry no pic handy

[Mark Julicher]

Re: Wing tank help?

I don't have a photo handy, but the gluing flange looks like the round finger dialing ring off an old style telephone.

[Pearson]

Re: Wing tank help?

If you had the type of gas cap I have on my plane, it looks like you would almost have enough of the neck sticking up. Putting something under the forward lip of the tank would help. But with the cap shown in the picture, it looks like you need to raise the tank almost an inch. I think I would try to find a different style gas cap.

[Mark Julicher]

Re: Wing tank help?

Try putting some 3/4 inch thick, hard felt under the front and rear lip of the fuel tank before you strap it down. As long as the tank and mounting straps stay below the profile of the ribs it should be just fine.

[1938BF50]

Re: Wing tank help?

I would really like to see a pic of this "gluing flange" that you are talking about. As far as lifting the tank with thicker felt...I can't. The height of the tank is limited by the drag wires penetrating the tank. I have it lifted as far as possible with 1/4" tubing cushioning the drag wires. I ended up pulling the tank flange up another 3/8" using a threaded rod as a jackscrew. The tank now looks like it follows the proper profile across its form. It was pushed down a bit as shown in the first pic.

Anyone have any comments about the quality of the wing tanks being produced by Wag-Aero? I am about to order a LH tank.

[Ragwing nut]

Re: Wing tank help?

[mulwyk]

Re: Wing tank help?

Mike:
First picture is the fuel filler neck flange. I got a new one from the "factory" when they were selling parts. If you have trouble finding a new flange, PM me and I'll send you this old one.

The next picture shows a tractor gas cap with a vent tube. The third photo is the bottom of a tractor gas cap, it's clamped on the drill press, gasket removed. Note the thin bottom edge. That thin edge fits into the recess formed in the fabric by the flange.

[1938BF50]

Re: Wing tank help?

Bob,

PM sent

[NY86]

Re: Wing tank help?

Don't know if this will solve your problem, but it worked for me on a Cessna 140 once.

Put the head of a ball peen hammer into the tank, hook the edge and pull up...

[1938BF50]

Re: Wing tank help?

OK, I got the flange that Bob sent me......

Setting the flange over the filler neck(either way) prevents the gas cap from fully seating. Does anyone have a pic of an uncovered setup that works? I am ready to just order a couple of the flanged filler necks out of Wag and weld them on to my tanks. Any reason why not? They look to be about an inch higher than the std neck.

[Robert Lees]

Re: Wing tank help?

Here's an extract from my website:

"New threaded fittings (for filler neck, outlet and fuel drain) are welded in (the tanks). Reinforcing plates are welded at the same time to spread the load when connecting up. Filler neck screws in.

All tanks are leak-tested after welding in new fittings. Also tests condoms. Pumped up, remained up for 24 hours, only wish I could say the same! One of four tanks leaked at a hairline crack on one weld, I used gas-fitter's spray to find source of leak. Interestingly, all the condoms never leaked or burst.
Inflation was through Schraeder valve connected into fuel drain hole."









You can see how much taller the screw-in filler neck is here:

[1938BF50]

Re: Wing tank help?

That solves this issue!

You neck is probably 3/4-1" higher than my mine. I will order new flanges and necks. I like the idea of the reinforce plate on the outlet. I will incorporate the same.

[Robert Lees]

Re: Wing tank help?

As an addendum, when you get round to covering, make sure the filler neck is completely sealed by the fabric.

Any fuel leakage into the wing will ruin the rear spar.