E26-2 : How to clean that 1984 diesel tank....

[acubria]

I need to change the diesel sender in my original 1984 aluminum diesel tank. I will have a chance to take a look inside of the tank and I predict finding some of that dreaded diesel fungus that apparently can cause problems in the future.
Has anyone cleaned the tank before? Can you share how?
Is taking the tank out of the boat even an option without taking out the whole motor in the E26-2? via Lazaret...??
I am thinking of making some kind of dialysis machine for the tank : hose to pump out > pump > filter > hose to return diesel to tank. let it do a few cycles and hopefully catch some fungus in the filter. Any thoughts on this?
PO used Biobor JF and so did I the one time I filled the tank.

Looking forward to hear your diesel tank stories !

 

[Frank Langer]

I was religious about keeping water out of the fuel tank, adding Biobar and fuel additive with each fill in our 1984 E30+. Despite this, our fuel tank began to "sweat" diesel fuel on the underside to the point where I had little option but to replace the tank.
I'm guessing that with your boat being 1984, you may be close to that, so you may want to be proactive and replace it.
Frank

 

[Christian Williams]

The primary filter does the dialysis already. To physically clean the tank you'd need an inspection port. You can inspect the inside through the sender port with a $30 endoscope on an iPhone.

A little crud is expected. Unless you experience a lot of clogged filters--say more than one a year--I'd say you can sleep easy.

I did install inspection ports, but then the E38 tank holds 55 gallons and I was heading offshore.

 

[Alan Gomes]

I need to change the diesel sender in my original 1984 aluminum diesel tank. I will have a chance to take a look inside of the tank and I predict finding some of that dreaded diesel fungus that apparently can cause problems in the future.
Has anyone cleaned the tank before? Can you share how?
Is taking the tank out of the boat even an option without taking out the whole motor in the E26-2? via Lazaret...??
I am thinking of making some kind of dialysis machine for the tank : hose to pump out > pump > filter > hose to return diesel to tank. let it do a few cycles and hopefully catch some fungus in the filter. Any thoughts on this?
PO used Biobor JF and so did I the one time I filled the tank.

Looking forward to hear your diesel tank stories !

Another E26-2 owner (I forget who) said that he was able to pull the tank through the cockpit locker.

 

[JSM]

A few years ago I had to pull the tank on my 34-2 to have a couple of mounting tabs rewelded. I found a shop that specialized in semi trailer truck tanks that did the welding as well as cleaning out the tank. My tank is an '87 and was in good shape internally.

 

[Loren Beach]

Unfortunately it is common to find that old and unaddressed water corrosion in a tank bottom or corner has caused pin hole leaks in the metal.
Some owners here have had good luck with coating the inside of the tank after a thorough cleaning (and this will likely require a new cleanup port anyway. A really good welder can cut out the corroded part and weld on a new piece, but getting the weld to really stick to the old aluminum is difficult.
As others point out, finding a good shop is 90% of the solution. And do not be too surprised if they advise replacing the tank. Some years ago, needing more capacity, we had a new tank fabricated. This also solved other problems, like the lack of clean outs, better locations of hose connections, and the addition of a new gauge.

 

[Rocinante33]

Get a long piece of dowel or even a yardstick and firmly attach sponge or rags which will not drop particles and stick it down through the sender hole. Then just physically "scrub the low corners as best you can. Then try to slosh clean fuel and pump it through a filter and circulate it. They call that, "fuel polishing." Maintain fire safety!

I have an old electric pump which if I was doing the job, I would hook it up to a diesel filter and hoses to drop into the tank and circulate the fuel through it for a while.

 

[acubria]

Get a long piece of dowel or even a yardstick and firmly attach sponge or rags which will not drop particles and stick it down through the sender hole. Then just physically "scrub the low corners as best you can. Then try to slosh clean fuel and pump it through a filter and circulate it. They call that, "fuel polishing." Maintain fire safety!

I have an old electric pump which if I was doing the job, I would hook it up to a diesel filter and hoses to drop into the tank and circulate the fuel through it for a while.

Great ideas. I am sure they will help me with this rather quixotic plan

 

[Mr. Scarlett]

unaddressed water corrosion in a tank bottom or corner has caused pin hole leaks in the metal

My previous boat had this along with a weeping fitting. Even though a tape measure said there was "just enough" space to get the tank out, it was a complete nightmare.
So I filled it with water, cut the top off and added to the welders list. This also allowed me to reduce the height of the tank by 3/8" which was all it needed to go back in nicely.

 

[Dave G.]

I don't think you can clean it properly through the sender port. After 37 years there will be a lot of crud in your tank, there was in mine. I got almost a quart of crud out last year when I had to do a leak repair. I had to cut an access port to facilitate the repair but couldn't of cleaned the tank thoroughly without it either. As noted above you can have a look see through the sender port since you'll have it out anyway and maybe you'll get lucky !