Fuel Tank Installation...

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Fuel Tank Installation...

Postby Clark in AZ » Thu May 16, 2019 1:13 pm

Ok guys, I'm attempting to mount my fuel tanks (SuperSTOL). Any tips, tricks, gotchas?

I know you're supposed to "level" the tank with washers, but level in relation to what? Since I have no access to the front bolts on the compression tubes once the tank is in place, how do you know how many washers you need on the front bolts? I can't see them with the tank in there?

Any easy methods of projecting where you need to drill the holes for the pickups.

Sorry for the stupid questions but the manual sucks. :?

Pics would be nice if you have them, thanks in advance!
Clark
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20190516_100128 - 800x450.jpg
Building SuperSTOL Kit 512
Cave Creek, AZ
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Re: Fuel Tank Installation...

Postby Clark in AZ » Thu May 16, 2019 9:54 pm

Ok, I played with it awhile and I've been able to get the inboard side of the tank to line up with the compression tube as seen in the pic. However, the outboard side of the tank does not rest on the compression tube at all. There is a small 1/4" gap. I was able to get the compression tube lined up with the tank flange but that gap is still there (pic 2). Finally, if I clamp the flange to the compression tube, it lines up ok (pic 3).

1. Is this normal?

2. Should the tank flanges rest on the compression tubes on both sides without clamping?
Attachments
20190516_161217 - 800x450.jpg
Pic 1
20190516_161226 - 800x450.jpg
Pic 2
20190516_161236 - 800x450.jpg
Pic 3
Building SuperSTOL Kit 512
Cave Creek, AZ
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Re: Fuel Tank Installation...

Postby BDA » Fri May 17, 2019 9:56 pm

Clark
There should be a strip of rubber between square tube and tank flange. Punch bolt holes in rubber larger than bolts and super glue down.

Drill holes for tank bolts where you can reach them through flange holes.

Use washers to raise tank so it is above the bottom of wing rib.
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791F8127-52C7-49C6-9AB0-12A9041C4F9C.png
Bolt w rubber isolater
SuperStol XL With Titan 340
#486 - N331AK
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Mods in progress: Wing extensions, Airfoil tail ribs
Goal: 15mph no wind
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Re: Fuel Tank Installation...

Postby AV8R Paul » Sat May 18, 2019 11:09 am

I agree with Shawn. I’d would recommend using a rubber gasket at each mounting angle, and make it over the edge closest to the tank so you can push it down and push it in between the side of the tank and the bracket, to prevent wear of the tank and future leaks in the tanks.
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SuperSTOL XL - N357TX - Titan 180 HP (Purple Haze)
S/N JA498-11-16
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Re: Fuel Tank Installation...

Postby Clark in AZ » Sat May 18, 2019 11:51 am

Thanks guys, I appreciate the feedback. Good ideas.

Clark
Building SuperSTOL Kit 512
Cave Creek, AZ
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Re: Fuel Tank Installation...

Postby antonxtiger » Thu Jul 11, 2019 2:46 pm

I was experiencing all of the above situations with my tank install also. What gasket material and source do you recommend? Thank you all. I would be hosed without this forum. Mark.
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Re: Fuel Tank Installation...

Postby AV8R Paul » Thu Jul 11, 2019 10:39 pm

I really don’t think “Leveling” is the right term. You are trying to fit the tank into the envelopes of the airfoil shape, you do not want the tank stick out above the airfoil shape on the top of the wing or out of the bottom. Effectively your trying to equalize the tank within the wing airfoil. You also don’t want to have the tank seesaw on the mounts and then bolt it down it will cause undo stress which can cause warpage of the wing, stressing the welds in the tank, possibly causing cracks and leak. The shimming with washers is to eliminate the rocking.

Make sure it fits within the envelope, shim the rock out with washers, and bolt it down. It’s a fuel tank, it really doesn’t need to be precisely level or what ever you want to call it. As long as the fuel can flow from the tank to the header you are fine. The Fuel will flow.

That my 2 cents, does anyone disagree, or have a different idea or thought?

Paul Z
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SuperSTOL XL - N357TX - Titan 180 HP (Purple Haze)
S/N JA498-11-16
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Re: Fuel Tank Installation...

Postby BDA » Fri Jul 12, 2019 12:37 am

I used the black roll that was in my kit - I think
Any sheet rubber will work
Make sure that the sides of the tank dont rub up against the mount flange on one side or the other.

Paul is right - although I think it is different for the SS and Highlander.
SuperStol XL With Titan 340
#486 - N331AK
Shawn Taplin
Mods in progress: Wing extensions, Airfoil tail ribs
Goal: 15mph no wind
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Re: Fuel Tank Installation...

Postby AV8R Paul » Fri Jul 12, 2019 11:04 am

Another 2 cents comment. I would use a straight edge to assure the tank does not stick above the two ribs on either side. I would also use rubber pads under each mounting point to minimize the effects of vibration.
AV8R Paul
Certified Light Sport Repairman LSRM-A
SuperSTOL XL - N357TX - Titan 180 HP (Purple Haze)
S/N JA498-11-16
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