Lots of water in tank 67C

[ragedracer1977]

3 hours ago, chriscalandro said:

Well, it’s not coming from the cap...

Ok, I'm in.

[chriscalandro]

59 minutes ago, ragedracer1977 said:

Ok, I'm in.

I was going to go to paint, but then I remembered I’m on my original 67 sealant. I’m going there first, then paint, then avionics. 

[FloridaMan]

As a note, sometimes when I park, I'll put blue painters tape over the caps to ensure nobody accidentally fuels my plane instead of somebody else's as well. Another thought is to use those six inch silicone shower drain covers with big magnets to hold it over the center of the cap. I don't like how water pools by the lever. 

[chriscalandro]

This mystery is ongoing. I recently covered the entire filler assembly And inspection panels with many layers of painters tape. A few days later after some rain, no change. Same amount of water in the tanks as usual. No sign of fuel leakage anywhere. 

I’m on my 4th oring in that tank since I started this  

I am open to whatever crazy ideas anyone has. 

Edited February 18, 2020 by chriscalandro

[HRM]

1 hour ago, chriscalandro said:

This mystery is ongoing. I recently covered the entire filler assembly And inspection panels with many layers of painters tape. A few days later after some rain, no change. Same amount of water in the tanks as usual. No sign of fuel leakage anywhere. 

I’m on my 4th oring in that tank since I started this  

I am open to whatever crazy ideas anyone has. 

I am now guessing a seam on the top of the wings. I mean, how else is it getting in? Of course, why would seams on both sides be leaking.

 

[chriscalandro]

1 minute ago, HRM said:

I am now guessing a seam on the top of the wings. I mean, how else is it getting in? Of course, why would seams on both sides be leaking.

 

It’s just one side. The left side. 
I would think if it was a seam you would see fuel coming out when it’s full, and that isn’t the case. 
 

Edited February 18, 2020 by chriscalandro

[HRM]

5 minutes ago, chriscalandro said:

It’s just one side. The left side. 
I would think if it was a seam you would see fuel coming out when it’s full, and that isn’t the case. 
 

OK, so throw a tarp over the left wing, violate Pilot Law and pray for rain, then check again.

As for fuel out the top when full, not necessarily. Of course, at this juncture, you are ready to try anything, no?

[chriscalandro]

I don’t have a tarp but I have lots of painters tape. 

[OSUAV8TER]

Have you swapped fuel caps? I.e. have you taken the right cap to the left side and the left side to the ride side to see if the problem travels? You said it's not the cap but can you elaborate how you came to the conclusion?

James

[chriscalandro]

Yes. I swapped the caps and the problem stayed on the left side. I completely covered the cap and access panel, and still got water. 

Edited February 18, 2020 by chriscalandro

[MikeOH]

Get the left tank down to 1/2, or less.  Get a camera, or some way to view, in the tank.  Then take a hose to the top of the wing and see if any water starts leaking in.

[Guest]

9 hours ago, chriscalandro said:

This mystery is ongoing. I recently covered the entire filler assembly And inspection panels with many layers of painters tape. A few days later after some rain, no change. Same amount of water in the tanks as usual. No sign of fuel leakage anywhere. 

I’m on my 4th oring in that tank since I started this  

I am open to whatever crazy ideas anyone has. 

What is the condition of the cap lock rings ?  Any corrosion or pin holes?  Have you pressure checked the tank through the vent fitting per the SB?  If water can get in, air should get out the same path.

 

Clarence

[chriscalandro]

41 minutes ago, M20Doc said:

What is the condition of the cap lock rings ?  Any corrosion or pin holes?  Have you pressure checked the tank through the vent fitting per the SB?  If water can get in, air should get out the same path.

 

Clarence

The cap lock rings seem to be ok. The caps hold water in them after it rains, and I’m pretty sure it’s evaporating.  
 

I’m going to pressure test it next week when I have more time. 

[BKlott]

We had a problem with water in the right wing tank of our Grumman Cheetah. In looking in the filler neck you could see what looked like a big clear bubble of water down there. This was even after having drained samples until we got nothing but 100LL!

It turns out that somewhere in the Cheetah’s past, some bozo replaced the quick drain in that tank with an incorrect part, one whose pickup was at a higher level than the correct part. This allowed water to remain in the tank even after we had drained out all the water, SO WE THOUGHT, during preflight. Of course, there was no log book entry to document this “work”.

So, I will suggest that you double check and verify that you have the correct quick drain in your wing.

[chriscalandro]

I’m sure the quick drain is correct. That would not be the source of water entry. 

[Guest]

10 minutes ago, BKlott said:

We had a problem with water in the right wing tank of our Grumman Cheetah. In looking in the filler neck you could see what looked like a big clear bubble of water down there. This was even after having drained samples until we got nothing but 100LL!

It turns out that somewhere in the Cheetah’s past, some bozo replaced the quick drain in that tank with an incorrect part, one whose pickup was at a higher level than the correct part. This allowed water to remain in the tank even after we had drained out all the water, SO WE THOUGHT, during preflight. Of course, there was no log book entry to document this “work”.

So, I will suggest that you double check and verify that you have the correct quick drain in your wing.

That story of wrong fuel drain valves is pretty common around here.

Clarence

[carusoam]

What type of steel is the cap mounted in? (This part is often called the fuel neck)

1) Shiny... Stainless...

2) Dull, grayish, often painted... mild steel...

Do you ever see tiny rusty bits come out when sampling fuel?

Best regards,

-a-

[chriscalandro]

21 hours ago, carusoam said:

What type of steel is the cap mounted in? (This part is often called the fuel neck)

1) Shiny... Stainless...

2) Dull, grayish, often painted... mild steel...

Do you ever see tiny rusty bits come out when sampling fuel?

Best regards,

-a-

I don’t know where my picture of the top is, but here’s one from the bottom. It appears good. And I’ve taped it off to isolate it with no change in results. 

[carusoam]

That looks like the dull gray of mild steel... but it isn’t showing any rust like expected..

Wait a minute...

Where is the rust?

where is all the sealant?  Wet wings typically have lots of sealant along all the seams and rivet lines inside the tank...

I think I see lots of clean metal and scratches as if somebody did some sanding...?

Might be a good time to check the logs again. Or take the same pic of the other tank...

Find Alex’s reseal thread... see if his pics of sealant everywhere match what you have...

Looks like somebody stole your sealant...
 

Find out what sealant is in there... it is so light, clear, see through... it doesn’t match expectations... of dark, easily seen, spread on prone to leak areas...

 

Then the rest...

Note the seal between the wing sheet metal and this piece that is riveted in place....

It is quite possible that you can test the seal...

blow some air in the tank’s vent.  It shouldn’t be escaping...

Great test for you lung capacity too... 

It may take two people... one to supply the air, the other to listen for where the leak is...

Compare your methodology with the other tank...

For some reason... a small break in the seal at the fuel cap... has a magnified affect of collecting quarts of rain water...  a lot of rain flows down the wing, accross the cap then towards the ground...

After that... look up Dmax’s method of leak testing... essentially using a vacuum cleaner to blow air in the tank...

Doc graciously supplied an SB for something similar...

Just use caution, compressed air over large Surface areas can generate some really strong forces...

The leak you are trying to find doesn’t require any pressure stronger than the weight of rain water on the wing...

PP thoughts only, not a mechanic...

Best regards,

-a-

[EricJ]

Yeah, I'd have expected to see some sealant in there.

SBM20-229a says not to apply more than 1/2 psi of pressure on the tank for leak checks, but if you do that you should still be able to see any leaks by spraying soapy water around the seams on the wing, caps, etc..   

[chriscalandro]

You know what, I don’t actually know what that picture is of because my filler necks are in the access panels and those aren’t access panels. 
 

I’ll take pictures of them tomorrow if I get a minute.  

[ragedracer1977]

46 minutes ago, chriscalandro said:

I don’t know where my picture of the top is, but here’s one from the bottom. It appears good. And I’ve taped it off to isolate it with no change in results. 

Wheres the sealant?!

[chriscalandro]

10 minutes ago, ragedracer1977 said:

Wheres the sealant?!

I think I just realized this isn’t actually a picture of my airplane  I have no idea where this picture came from but it was near my pictures of inside my tank.

 

My filler neck is mounted to the access panel. 

i should have looked before I posted it.  Embarrassing.  

It’s been a long day. 

Edited February 20, 2020 by chriscalandro

[chriscalandro]

Ok. 
This is how it was taped off. The picture is with the tape removed and replaced but that’s how it was before I checked it. 
 

the water bottle is water/fuel as sumped until it was fuel only. 
 

the inside of the tank picture is of the filler neck where the rust looks the worst. It’s not easily seen in the picture but I don’t see any light leaking through. It’s difficult to check but I really don’t think it’s the cap. 

[EricJ]

Pressure test with soapy water should be your friend.   Supposedly 1/2 psi should do it sufficiently.   That's probably light blowing on a hose on the vent with the fuel selector shut off.   You can get a gauge cheap to put in-line to make sure if you want.   If there's a leak in the cap or a seam you should be able to find it that way.