Sonex fuel tank revision
Posted: Wed Oct 14, 2015 9:37 pm
by mike.smith
If I’m reading this drawing revisions bulletin correctly, it sounds like Sonex is giving up on the pre-moulded fittings and going with the Oops fitting as the standard fuel fittings.
http://www.sonexaircraft.com/support/sonex_revs.html
10.14.15 SNX-G02 A – –
Removed scratch-build detail. Removed pre-molded threaded fittings. Added Oops fitting installation details. Removed felt covering required for scratch-built aluminum tanks. Removed drawing from Sonex plans set. Drawing now included with each fuel tank. Download: SNX-G02_A_Fuel_Tank.pdf (http://www.sonexaircraft.com/documents/ … l_Tank.pdf)
Re: Sonex fuel tank revision
Posted: Wed Oct 14, 2015 9:50 pm
by fastj22
This is a positive move by Sonex.
Re: Sonex fuel tank revision
Posted: Wed Oct 14, 2015 10:10 pm
by gammaxy
I agree… I’m currently kicking myself that I did not take the general advice of the forum and install the fittings from the beginning. The only fittings that are weeping are the unused sight-tube fittings, so I’m trying to come up with a patch to completely block them off without having to remove the tank.
Re: Sonex fuel tank revision
Posted: Wed Oct 14, 2015 10:13 pm
by fastj22
If you smell a hint of fuel when you open the canopy, you know you are entering a Sonex!
Re: Sonex fuel tank revision
Posted: Wed Oct 14, 2015 10:32 pm
by Bryan Cotton
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!
Re: Sonex fuel tank revision
Posted: Wed Oct 14, 2015 11:06 pm
by Waiex 49
I believe this is a good move by Sonex.
For what it is worth:
If you have to remove the tank to replace the fittings, I found the easiest way to go was to remove the rudder pedal mounting brackets and let the entire rudder pedal assembly lay on the fuselage floor. This allows up and down movement of the tank, which I found much better than the tilt and slide method specified in the Sonex instructions. Removing the brackets requires drilling out 10 rivets, but that shouldn’t hold anyone back.
I did not install the outer o-rings as specified by Sonex. The inner o-ring provides the sealing. The outer o-rings twisted and squirmed out of position as the nuts were tightened. I omitted the outer o-rings and used washers under the nuts.
Although not specified by Sonex, I used LocTite on the nuts. Maybe I am overly cautious but I didn’t want these parts to come loose during flight.
I’m glad Sonex made this change. Now I can stop cursing in the general direction of Wisconsin.
Re: Sonex fuel tank revision
Posted: Wed Oct 14, 2015 11:19 pm
by gammaxy
Bryan Cotton wrote:If I was trying to stop a weep I would pro-seal over it on the outside.
I’d like to consider pro-seal, but the only documented pro-seal fix I’ve found involves sandwiching the pro-seal under an aluminum plate that is screwed into the plastic. I took this to mean pro-seal doesn’t stick well, but I’d be happy to put a glob over both fittings and be done with it.
What I’m considering instead is making a patch out of ~1/8" thick HDPE sheet with a pocket machined into it so I can place it directly over the plug and fitting and it will contact the surface of the tank. Then use this system on the tank and patch:
http://www.loctiteproducts.com/p/sg_pls … System.htm
I’ve experimented with the loctite system and it seems to work, so I’m cautiously optimistic that this will be a permanent solution.
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 1:51 am
by peter anson
I used PR1422 which is a polysulphide compound like Pro-seal to repair a leak at the fuel level sender on my Sonex. The PR1422 appears to adhere to the plastic. I do have a “top-hat” fitting clamped to the fuel level sender (see photo below) and that might be holding the rubber in place, but when I did the repair I was counting on the glue bond to the top hat to give support to the sender, and it does appear to have worked that way.
Pretty isn’t it? The fix was not an easy one. See http://sonexaus.wikispaces.com/Peter+Anson±+Sonex+894 about 2/3 down the page for details.
Peter Anson
Sonex 894
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 5:47 am
by Sonex374
This stinks new buyers get correct method and I must buy corrective measures
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 12:17 pm
by kmacht
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
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 12:52 pm
by marsolgp
Another option, that I learned about from fellow builder, 3M Scotch-Weld DP8005… A little pricey but was made for and works great on these plastics.
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 1:34 pm
by Sonex1542
Help me understand, The Great Sonex Fuel Tank Fiasco of 2015!, since I ordered a tank last year that is still not in the fuse.
I get that the current fittings get loose in the rotated plastic then leak. Is sonex sending out oops fittings with new tank purchases? Do I attempt to install without installing oops fittings? Do I have to buy the fittings? Least they can do is send out oops fittings for all old tank sales if needed. :x
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 6:02 pm
by LarryEWaiex121
I’m reading all this leaking stuff on fuel tanks and wondering what I missed out on?
My Waiex kit was shipped to me in April of 08 and it has the translucent colored poly tank. I’ve never had a leak in the cockpit other than not getting the snap over stopper tight enough after sitting for extended periods. The butalene rubber or how ever you spell it shrinks with no contact with the fuel it seems.
Back to the fittings issue. Did Sonex change their tank manufacture or design along the way that causes these fittings to fail or I’m I just lucky and not had a failure YET?
I never followed the discussion before, but now I’m wondering if my tank is on borrowed time?
Larry
Waiex 121YX , Jabiru 3300, 449 hrs
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 7:03 pm
by SonexN76ET
Some people have tanks that do not leak. The leaks are often caused by overtorquing the fittings screwed into the tank or builders not protecting the fittings from vibration or side loads or hanging heavy things off the hoses and fitttings. Sometimes the brass fittings or aluminum fittings people screw into the fittings seize and then cause a leak when torque is used to try to remove them. Some people are just unlucky and have a fitting start to leak for no good reason. So far I have not had a leak. I think if I ever do get one, I will use the 3M product Geary recommended along with an oversized aluminum washer on the outside of the fitting to try to stem the leak.
I once thought I had a leak, but it was the teflon paste I used on the Princeton fuel probe allowing seepage. I replaced the teflon paste with “fuel lube” and that put an end to the seepage.
I have been very careful not to put any strain on my fuel tank fittings, so perhaps that has helped.
I also agree with Keith that I do not like the oops fittings. I used one to plumb a fuel return line since I am running a fuel pump. I think the oops fittings are too light, don’t have a wide enough base, and don’t hold the torque on the nuts holding them in place very well. I would like to recommend that Sonex use an oops fitting that is heavier and has a wider inside base to allow it to hold more torque on the inside of the tank to get a tighter squeeze on the outside nut. Perhaps a lock washer or lock nut too?
Jake
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 7:25 pm
by rizzz
Sonex374 wrote:This stinks new buyers get correct method and I must buy corrective measures
As a user who installed the tank as-is before knowing about the potential issue, yes it sucks knowing that I might have a very tricky fix to do some time in the future.
That said,
I think this is a good development. Sonex recognised there is a problem and it is big enough that there is a need to do something about it.
They listened to their customers and acted, not every manufacturer does this.
Not many things in this world are perfect from the start so it is good to see they still improve where/when needed.
Re: Sonex fuel tank revision
Posted: Thu Oct 15, 2015 7:40 pm
by mike.smith
LarryEWaiex121 wrote:I’m reading all this leaking stuff on fuel tanks and wondering what I missed out on?
My Waiex kit was shipped to me in April of 08 and it has the translucent colored poly tank. I’ve never had a leak in the cockpit
125 hours on mine and also no leaks. Based on others’ issues I do look for a leak by running my finger around the base of the fittings as part of my preflight.
Re: Sonex fuel tank revision
Posted: Fri Oct 16, 2015 6:19 am
by jjbardell
I may not make any new friends with this post, but several of the posts are referencing one of the business limitations which prevents Sonex from being perceived as a top tier company. Without the Sonex community helping each other, my option is that Sonex would not have the success it has had. With that said, I can’t speak highly enough for some of the sales and management team there.
I agree with several of you. Sonex needs to take a stronger, less ambiguous, leadership role in guiding builders. Enhancements / changes is ‘moving forward’, and that’s good thinking and business development but without providing guidance to those stuck in the middle (i.e.- have tank but not installed), it causes confusion and frustration.
So Kerry, what is Sonex’s recommendation; do builders with a tank not installed put the oops fittings in now as preventative measure or do we deal with it later, if/when the issue rises?
Rutter / Sonex1542 - in my opinion, sometimes timing is unfortunate. A few weeks after I received my turbo Aerovee kit with the $250 prop hub assembly option, Sonex announced free prop hub assembly as a special. They were going to get back to me about some online credit. That was back during Oshkosh…I’m still waiting.
I hope Sonex sees this thread as constructive feedback and an opportunity, not as a negative.
Re: Sonex fuel tank revision
Posted: Fri Oct 16, 2015 7:51 am
by Sonex374
Jjbardell I respond to let you know I 'm not angered by your post. My post was one of frustration. I had purchased the tank in the past year or so had just ordered and received felt etc. Then as i’m installing out comes the revision.
So do I need the felt nothing posted one way another also now oops fittings?
Frustration is heightened by the fact full information is not received as to what led to the revision,if it was found that the original did not preform to expected result say so and let’s move on. But to have to purchase corrective methods prior to using that purchased but not yet installed is not good practice. That is akin to buying two of everything just in case the first was not right.
I appreciate your post and the Sonex company I just want to get done and fly.
Re: Sonex fuel tank revision
Posted: Fri Oct 16, 2015 8:18 am
by DCASonex
Now that Sonex is making the “Oops” fittings standard perhaps they will go the rest of the way and have fittings, (not oops fittings) made to order. Last I inquired, they purchased these, and could not even advise material grade of 0-rings supplied. O-rings for inside of my small fittings looked to be one size too large, and if O-rings are used under the nuts on the outside, nuts should have a recessed groove to keep them from being squeezed out to the side. Getting rid of the molded in fittings is a big improvement, now finish the job, proper ones with Aero-Conversions red anodizing would look professional and make good lemonade out of these lemons.
David A.
Re: Sonex fuel tank revision
Posted: Fri Oct 16, 2015 8:21 am
by lpaaruule
That’s me too. I have a fuel tank sitting on my bench, and plan to install it in a few weeks. I had decided that I’d use fuel lube and just not overtighten the fittings, as Sonex had stated was the cause of the issues. I now feel I need to re-access the decision. So do I stay the course and not use the “oops” fittings, or do I modify my fuel tank, and risk ruining it, and needing to buy a new tank?
I guess if I were given the option of paying an extra $320 now to never have to remove a leaky tank, I’d pay the $320. So from that standpoint, I suppose it’s worth the risk to try to “upgrade” my tank with “oops” fittings. Assuming that the “oops” fittings aren’t included with the price of a new tank, I’d have to buy them anyway.
It sure would be nice if Sonex would give us a nice guy deal on “oops” fitting though. I’d also like them to offer or suggest a tool(s) for reliably removing the internal plastic ridge.
Re: Sonex fuel tank revision
Posted: Fri Oct 16, 2015 8:42 am
by 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
Re: Sonex fuel tank revision
Posted: Fri Oct 16, 2015 10:01 am
by 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.
Re: Sonex fuel tank revision
Posted: Fri Oct 16, 2015 1:22 pm
by 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
Re: Sonex fuel tank revision
Posted: Sat Oct 31, 2015 3:08 pm
by 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
Sonex fuel tank revision
Posted: Sat Oct 31, 2015 5:31 pm
by 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
Re: Sonex fuel tank revision
Posted: Thu Nov 19, 2015 12:49 pm
by SonexEZ
fastj22 wrote: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 !!
Re: Sonex fuel tank revision
Posted: Fri Dec 11, 2015 7:44 am
by SonexEZ
Bryan Cotton wrote: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
Re: Sonex fuel tank revision
Posted: Fri Dec 11, 2015 8:35 am
by SonexEZ
kmacht wrote: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
Re: Sonex fuel tank revision
Posted: Fri Dec 11, 2015 2:52 pm
by 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!
Re: Sonex fuel tank revision
Posted: Fri Dec 11, 2015 7:04 pm
by 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?