Fuel tank question/issue

[DesertFox4]

OFERGD- Aluminum tanks were used in the early Kitfox's with poor results. Since the tanks are bonded to the spars it flexes with the spars and the welded seems give up and leaks are the result.

[baronecozza]

Hi, I definitely would like to see your pics. I'm not at the point yet that I have to encounter your kind of problems, but I bought a project with installed tanks (How on Earth do I know which year/type they are?!?!?!), and have no other opportunaties than to either tear the tanks out, or follow your way...
Looking forward!
Hans

Hi Hans, let me know your email address in order to send the pictures.
Ciao
Marco

[baronecozza]

marco, thats a real horror story . there have been other problems with fibers noted on this forum . now youve got me concerned . i replaced one tank last winter and have over a hundred hours on it with no problems . i am planning on replacing the other tank this fall/winter . so , to seal or not to seal ? would be interesting to read about the seal you used but its not in english .

Hi,
here below the translation of the Tankerite characteristics.I know that 3M has a similar product to treat the tanks.
This is a permanent cycle corrosion protection for the remediation of internal ammalorati rusted and tanks, which form a capsule sealant, resistant to petrol, alcohol and fuels. Finally, here is the optimal solution to prevent and stop rust internal tanks cars and Motocycles, avoiding costly replacements as often unobtainable.
Our repair kit consists of three products, is easy to use, and is then available to anyone who wants to ensure economic and solving this problem permanently.
Operating instructions are clear and the result is professional.
The inner surface of the tank is coated with a resin corrosion, sealant and ceramic high and solid appearance. It is however at the same time extremely elastic, so as to form a capsule vibration-proof sealant and thermal stress of exercise (designed to withstand temperatures from-30 ° to + 120 ° C).
Porosity, crackles and sheet metal are therefore assottigliamenti wetlands permanently. To know more, consult also our FAQ.

[ofergd]

Steve
The tanks shouldn't be welded to the spars, just like tha fiberglass ones are bonded with an elastic bond. Similar design can be applied to the insallation of aluminum tanks. The tank I designed for a diferant plane is made of 0.1" 5052 aluminum and has internal semi ribs for strength so it can stand alone. It is straped down and not bonded to the spars.

[DesertFox4]

none of the failed aluminum tanks were welded in place only bonded like the fiberglass.

[Av8r3400]

Steve
The tanks shouldn't be welded to the spars, just like tha fiberglass ones are bonded with an elastic bond. Similar design can be applied to the insallation of aluminum tanks. The tank I designed for a diferant plane is made of 0.1" 5052 aluminum and has internal semi ribs for strength so it can stand alone. It is straped down and not bonded to the spars.

.1" thick?! That thing must have weighed a ton!

[Jerrytex]

My thoughts on the aluminum tanks were to make them like the poly wing tanks that just drop in to the existing fiberglass tanks. Then foam them in. This way they would not be structural and I would not have to worry about cracking. I would like to find an old Kitfox tank that I could use to make my prototype rather than cut my existing ones and find out that I cant' make them fit.

I will look into the Rotomolding as well. Also after hearing that "washed" gas is working, that might be a viable option as well. Another person I was reading about is doing it with good results too. I would be a pain but worth it if it works.

[Av8r3400]

I will look into the Rotomolding as well.

Buying them from WINGTANKS.COM would be considerably easier and cheaper than tooling up a one off, redundant, roto-mold run.

[Andrew G]

yeah, that aftermarket solution looks good... those are "cross-linked poly" tanks, which is what you want from a product perspective. That's what they build in the marine business... I can't quite understand the installation, but you K'fox builders probably understand it.

Perhaps one day, the factory will commission two molds (left and right) and sell these tanks as part of the kit... ethanol isn't going away, I hear it's going to get worse... and those fibers scare the heck out of me.

Andrew

[mclayton]

For what it is worth....

I am rebuilding a Kitfox II, which came with aluminum fuel tanks. There is no evidence of leakage, and all the welds look solid. The manual calls for the riveting of the aft end of the tank to the spar with five rivets. Mine only had two rivets. As I rebuild the wings, I plan to reuse the aluminum tanks, but will try to cushion them between the spars with some elastomeric material, and may also consider trying to come up with some strapping arrangement, which seems to be the more standard method of installing fuel tanks. Using rivets seems to me to be asking for trouble, as the wings do flex in flight.