Sonex fuel tank revision

[bnvoss]

Purchased kit in 2003 with translucent tank with molded fittings. Now have 480 hours on her without any fixes or leaks. Last year, I removed the fuel gage line and installed plugs. Still no leaks.

Bob, Texas Sonex 550, Jabiru 2200, 480 hours

[fastj22]

I installed my tank per the manual with zero leaks too. After I switched to MoGas and killed my capacitance fuel sender, upon trying to remove the sender, the fitting spun requiring me to do the oops fix. This convinced me that the molded fittings were undersized.
I've had my head in and around 6 sonex and 4 had fitting problems of some sort.

The oops fittings could easily be made by someone with a lathe and machining skills. I agree there is room for improvement to them.

[kmacht]

That is exactly what happened to mine. I had major corrosion on the fuel probe and when I went to remove it the small fitting spun making me use an oops fitting to replace it. I haven't had any leaks out of the larger fuel tank fitting.

Keith
#554

[SonexEZ]

Has anyone added a fuel gage on top of the EIS or a RPM gage waiting on my torque wrench to come back from being calibrated then i will be getting towards the end of correcting everything on this Sonex

[Sonex1517]

I installed a VDO RPM gauge but have had trouble calibrating it. So I installed a TonyTach and it has been a great solution.


Robbie Culver
Sonex 1517
Chicagoland
Tails and Wings complete - finishing fuselage.
N1517S reserved

[SonexEZ]

If you smell a hint of fuel when you open the canopy, you know you are entering a Sonex!

Hi I have had this sonex since september at this time i have it at home going though it from one end to the other i found so many safty hazards also replaced the com radio that works excellent now . I just wanted to say i put taflon paste on the fuel sensor and i dont have any smell any more of fuel i also thought good time to see if the amount is correct after all i didnt build this unit . i went to the airport and got 6 gallons and put that into the empty take wow the sucker is right on the money . At least the builder did one thing correct !!

[SonexEZ]

If I was trying to stop a weep I would pro-seal over it on the outside. I know they say nothing sticks to the plastic but pro-seal is worth a try. On the outside of the tank there is no hazard.

I remember the earlier threads where builders wanted Sonex to do something. It seems they have listened!

My older sonex was weeping from the right side the small hex head , after trying several things and still weeped i HOT glued it no more weeps, I think it was weeping on the outside of the threds so no matter what you put on the threds it still weep , I used thred locker #2 as per sonex , sanded the tank cleaned with alcohal installed the small plug then hot glued it , no more smells of fuel

[SonexEZ]

I'm not thrilled with the oops fitting. I had to put one in where the fuel probe goes and it seems that it loosens up enough to start dripping every three to four months and I find a wet fuel soaked carpet. There is no safety or locking feature on the fitting and nothing stops the vibration from unscrewing it. It is a pretty poor design from an engineering perspective.

Keith
#554

I hot glued it

[Waiex 49]

Not thrilled with the ooops fittings either.
There is no locking feature and it would seem they could come loose pretty easy.
I'm not sure why Sonex chose this fitting, it looks pretty cheap. I would think something better could be found.
In my opinion, for fuel system components, quality should be the #1 factor not price.
I used a very generous application of Locktite on the threads, hoping that this will keep things from coming apart.
Hot glue sounds like an interesting fix. Or maybe PR 1422 as others have used.
You wouldn't want these fittings coming loose while you are flying around, that's for sure!

[Rynoth]

Regarding hot glue I might be concerned of either the fuel dissolving it, or small pieces of it breaking loose and entering the fuel system?