red-neck fuel-tank cleanup?

Tin Kicker · Jan 3, 2020

I've run across this occasionally on airplanes. Cut back the 1/4" of hose closest to the tank and remove it. You ought to be able to get a bent piece of shirt hangar wire into the end of the tube and pull it from the metal at least at the cut end. A touch of spray silicone lube in that end can help break the rubber adhering to the aluminum and the silicone does a good job of penetrating. Then try grabbing a hose and rotating it back and forth while pushing toward the tank. The silicone at one end and fuel at the other will help lube the process if you twist back and forth just hard enough to get a touch of movement between the hose and end of the nipple. Keep at it and the hose should slowly release as each cycle breaks a little more of the hose adhered to the nipple.

If that doesn't work the hose should have enough slack to be re-installed if you cut the end (about 3/4") off at the flared part of the nipple. If the hose doesn't even have that much slack it probably ought to be replaced anyway because a stretched fuel hose is really bad.

I've used a regular pair of pliers very gently to do the twisting. You just want to stretch the rubber of the hose while putting minimal force on the old aluminum weldment. It'll take a while and if you even think there is ANY indication the aluminum is yielding, stop and just cut the hose off.

kapnkd · Jan 3, 2020

False Bottom Riser for Fuel Tank (??)

bgary said:
I have never run my fuel level below half a tank in the past 3-1/2 years. I've basically topped up my tank at the end of each season, added some BioBor, checked/drained the Racor bowl and called it good.

As a result, I have no idea what (if anything) might be lurking in the bottom of my tank.

One of the items on my spring list this year is to do... "something" about that, under the theory that it is preventive maintenance. But what that something is, is not clear. I don't really feel like extracting a whole tank of fuel in order to see if I have a problem.

It occurs to me that I have one of those oil-change pumps, basically a 4-quart vacuum canister with a long hose for sticking down a dipstick hole. and sucking out oil.

Which started me thinking.... I could pump up the vacuum on that that thing, stick the hose down into the bottom-most corner of my fuel tank, and extract whatever is there. Bonus points for the fact that the canister is clear, so I could let the extracted stuff sit and see if there is water, sediment, growy-things, whatever.

Good idea? Horrible idea? Ineffectual idea?


Bruce

It DOES work! It's what we did when we emptied and pulled the tank on our E-32-II for making substantial repairs/reinforcements to the upper underside of the rudder post plate on the cockpit sole.

The old “While we are at it” axiom came into play and the tank then was also seriously cleaned of a LOT of unwanted contaminants and other mysterious creatures.

Although we do not need a new tank (yet) ...I got to thinking of how to perhaps construct a better/easier way of removing contaminates from our tanks.

There needs to be a low area for the heavier than fuel items to collect and a tube on top that can vacuum it out from a “sump” like area. …Sort of a false bottom in the tank that would have the heavy schtuff roll off to the sides and into a collecting area.

Here’s a basic concept sketch I did and am sharing in case anyone is thinking of having a new tank built. Notice the raised area false bottom is slightly angled to promote "gook" runoff towards the sump area as well. I’m sure there can be lots more improvements and ideas for it by all of you, but FWIW – hope this may be of help to someone along the way.

nquigley · Jan 6, 2020

4 holes in corner of fuel tank

Well, I wrestled the tank out on Saturday - thanks for everyone's advice.
- I used a heat gun on low setting to warm the hoses (held an Al foil reflector underneath for all-round warming)
- the rubber strap wrench didn't work - the rubber just stretched.
- gentle pressure back and forth with a large ViceGrip tool eventually loosened both hoses
- used the hose pick someone suggested to slightly lift the ends of the hoses, and sprayed a little WD40 in those gaps
- eventually, I was able to twist both hoses back and forth by hand
- the smaller vent hose had enough flexibility (just) to be pulled back and off the port
- I lifted up the forward end of the tank and twisted the whole thing back and forth, and forwards, until it eventually slid off its port

I cleaned the outside of the tank with Rustoleum gel rust remover and a steel wool pad.
I rinsed the inside of the tank with denatured alcohol ... sure enough, started seeing drips at the corner of the tank under the fuel pick-up/return ports
There was asphaltene/gunk build-up inside that corner, which was apparently reducing an otherwise steady stream to just drips
The outside of that corner had lots of corrosion pits - when cleaned with alcohol and a toothbrush and then poked with a few rivets of various sizes, you can see what I ended up discovering.

I'll install a 6/8" SeaBuilt inspection port near the fuel pick-up end this week, thoroughly clean the reachable inside surfaces (esp. the bottommost corner), and then take the tank to a local metalwork shop for repair.
Meanwhile, I have years of slow-leak diesel and gunk to clean out from the accessible parts of the bilge ...

Christian Williams · Jan 6, 2020

1. I wonder if one of our forum scientists could say what element it is, in the gunk, that corrodes the aluminum.

2. to clean out

I had a spill of fresh diesel last year. (Result of loose gauge in the sender port, which I had removed several times to confirm fuel level offshore. When I refilled the tank full upon return, the port was "under water" and dripped a quart of bright red diesel into the many-compartmented TAFG bilge).

The diesel got into the structure of the TAFG quite beyond the confines of the molded access compartments.

To get it all out required opening the TAGF drains so the entire structure could be flooded with detergent. It took about three complete fillings of the bilge before the red was gone. Auto bilge pump did the pumping out.

I started by using the oil change pump to individually evacuate the hidden bilge areas within the TAGF. That got most of the "red" so I could dispose of it at oil recycling.

After that it was just add detergent (I used just of basic stuff form Home Depot), flood the bilge to the floorboards, and turn on the bilge pump. Makes a lot of soap suds in the marina, so perhaps best done on a quiet day so as not to freak out neighbors.

Sounds elaborate, but it was easy and took only a couple of hours to have a pristine bilge again.

Tin Kicker · Jan 6, 2020

Good old Pine Sol works really well for bilge cleaning if left to soak for an hour or more. It seems to be a stronger degreaser than many of the soaps and detergents.

And you can finish with either a pine or lemon scent.
:egrin:

nquigley · Jan 6, 2020

Christian Williams said:
1. I wonder if one of our forum scientists could say what element it is, in the gunk, that corrodes the aluminum.

2. to clean out

I had a spill of fresh diesel last year. (Result of loose gauge in the sender port, which I had removed several times to confirm fuel level offshore. When I refilled the tank full upon return, the port was "under water" and dripped a quart of bright red diesel into the many-compartmented TAFG bilge).

The diesel got into the structure of the TAFG quite beyond the confines of the molded access compartments.

To get it all out required opening the TAGF drains so the entire structure could be flooded with detergent. It took about three complete fillings of the bilge before the red was gone. Auto bilge pump did the pumping out.

I started by using the oil change pump to individually evacuate the hidden bilge areas within the TAGF. That got most of the "red" so I could dispose of it at oil recycling.

After that it was just add detergent (I used just of basic stuff form Home Depot), flood the bilge to the floorboards, and turn on the bilge pump. Makes a lot of soap suds in the marina, so perhaps best done on a quiet day so as not to freak out neighbors.

Sounds elaborate, but it was easy and took only a couple of hours to have a pristine bilge again.

Thanks! - I was wondering how many gallons of de-greaser detergent to get at H-D. The answer seems to be 'many'.
I'll be sure to select a nice pine-scented detergent so the marina at least smells nice, while looking like it's been pranked by teenagers (a la - detergent in a park fountain).

I think (?) my tank corrosion is on the outside, where that tank was sitting in a little pool of leaked diesel and gunk, on a bed of fiberglass cloth - adds a variable to what could be etching the aluminum.

bgary · Jan 6, 2020

nquigley said:
Thanks! - I was wondering how many gallons of de-greaser detergent to get at H-D. The answer seems to be 'many'.

I had a bit of fuel in the bilge (and throughout the dark corners of the TAFG) a couple of years ago (*) I used "dawn" (yeah, the grocery-store dishwashing liquid) to clean in and around the grid.

It's a surprisingly effective degreaser.

$.02
Bruce

(*) I flushed the bilge with water, let it sit for a bit, soaked the fuel up off the surface with sorbent pads, and repeated until I didn't see any more red. The fuel-sheen-police in my marina are quite vigilant...

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red-neck fuel-tank cleanup?

Tin Kicker

Sustaining Member

kapnkd

kapnkd

nquigley

Sustaining Member

Christian Williams

E381 - Los Angeles

Tin Kicker

Sustaining Member

nquigley

Sustaining Member

bgary

Advanced Beginner