ExtraKatana

ExtraKatana

Well Known Member
I did not build my 6A, so I apologize in advance for not using the right terms, but will try my best...

I have noticed a very small amount of "liquid" seeping out from under my wing/fuse fairing on to the bottom of the port wing. The stain travels almost to the flaps after long flights. I removed the bottom part of the wing/fuselage fairing to expose the part of the tank that faces the fuse. I have taken a mirror and looked along the back of the tank...no visible leaks. No leaks also visible on the vent or main fuel coupling...or anywhere on the tank that I can see. I have pressured the vent line significantly and let sit for 45 minutes to an hour.....no leaks and the pressure relieves after sitting for the duration. HOWEVER, after flying the small amt. of seepage appears. After several hangar buddies got on the creeper and assessed the situation, some thought there was condensation coming from the tank or maybe the main line leading to the fuse. The condensation drips and the liquid trail forms. The liquid is always dried by the time I crawl out and remove the fairing....and the stain residue is odorless. I keep in a hangar that is somewhat cooler than outside ambient.

Has anyone experienced this???
 
ExtraKatana said:
I did not build my 6A, so I apologize in advance for not using the right terms, but will try my best...

I have noticed a very small amount of "liquid" seeping out from under my wing/fuse fairing on to the bottom of the port wing. The stain travels almost to the flaps after long flights. I removed the bottom part of the wing/fuselage fairing to expose the part of the tank that faces the fuse. I have taken a mirror and looked along the back of the tank...no visible leaks. No leaks also visible on the vent or main fuel coupling...or anywhere on the tank that I can see. I have pressured the vent line significantly and let sit for 45 minutes to an hour.....no leaks and the pressure relieves after sitting for the duration. HOWEVER, after flying the small amt. of seepage appears. After several hangar buddies got on the creeper and assessed the situation, some thought there was condensation coming from the tank or maybe the main line leading to the fuse. The condensation drips and the liquid trail forms. The liquid is always dried by the time I crawl out and remove the fairing....and the stain residue is odorless. I keep in a hangar that is somewhat cooler than outside ambient.

Has anyone experienced this???
Click to expand...

What color is the stain?
 
Color

I had compounded the paint and left some under the fairing.... it was the blue color of the compound.
 
Blue stain is also the color of 100ll fuel.

You might want to be really sure this is not a fuel leak----clean everything well, put it back together, and keep an eye on it.
 
Blue

It does not smell like avgas
The blue for sure is from the compound material that worked its way under the fairing.

I'm thinking of wrapping the area...vent and fuel lines under the fairing with a paper that discolors when wet, seal it back up and see what happens after a flight.
 
It's a Leak

So I cleaned off all the compound and stuffed some Kleenex behind the rear tank baffle and went for a one hour flight. Soaked up a quarter-size of fuel over two spots on the bottom/rear portion of the baffle...very slight. I can't pressurize the tank and get it to leak...only in flight.

After reading various methods of fixing this, I am thinking about removing the tank.
Other than the perimeter screws and the connections at the root, what is holding this tank on? Anything through the spar?
6A-Slow Build
 
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I know a guy with similar problem. His "leak" is toward the top of the tank and only happens with full tanks. If he fills, then flys it out, it leaks very little (about what you described) If he leaves tanks at half, he has no problem...
He put it on his "deferred" list. Not enough to really worry about right now...
YMMV,

Dm
 
Leak Fixed

Looks like a bolt going through the fuel sending sensor was the culprit.

Next question:
Attached is a pic of my main fuel line from the wing. Do you use the aluminum compression type ferules (on each end of the pic) that fell out between the flare and the male fitting? If so, where does one obtain?
TimDavie
 
Leak Fixed

Looks like a bolt going through the fuel sending sensor was the culprit.

Next question:
Attached is a pic of my main fuel line from the tank to fuse. Do you use the aluminum compression type ferules (on each end of the pic) that fell out between the flare and the male fitting? Very soft aluminium. If so, where does one obtain?
P1010021.jpg
 
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Leak Fixed

Thanks for your help.
Got it all sealed back up today and ground tested w/engine running for about 10minutes. No leak. I'll put an hour on it in the air and check again.
 
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