Advice for Diesel Tank(s)

[SpaceRnglr]

Wife said diesel smell had to go so the project to inspect the tank moved up the list. I am glad it did as when I removed the tank there was a puddle of diesel under the tank. I think the tank had a small leak, but a very slight poke with a scraper went straight through. Time for a new tank...

I have posted a picture of Elessar's tanks and a schematic of current and options. Elessar has 1 diesel tank (~180 liters) and 4 water tanks (310 liters total). She also has a water maker so I think I can live with less freshwater. The idea is to convert one of the water tanks to diesel. Actually it will have to be a new tank as the water hose connections are on the bottom of the tank...

There is very little space around the tanks so I need small and simple. Does my schematic below look reasonable? Any comments on either of my alternates?

[RaymondR]

Why not just replace the diesel tank?

[Sailorman Ed]

We had the same issue, took out the AL tank, wirebrushed it and ended up with lots of pinholes. Took it to a shop and they "wrapped" the bottom, did a nice job welding it on, leaked tested and painted for us.
Not cheap but a fraction of the cost of a new one.

[Deepdraft]

I had a small leak in a 30yo steel tank. I ended up cutting the top of the 70 gal tank out. I inserted a fuel cell from ATL, using the old tank sides and bottom as support. The poly tank comes with foam inserts that can be removed in order to collapse the tank and squeeze it through the available floor access. In my case it was a 13 inch square. Once the poly tank was inside the foam can be reinserted. I’ll upload a few pictures.

http://atlinc.com/marine.html

Regards,
Neil

[Deepdraft]

[Deepdraft]

[Deepdraft]

Not sure why Im getting duplicate image uploads...

[Deepdraft]

Foam inserts

[Deepdraft]

Refilling tank

[Deepdraft]

Tank buttoned up.

[Deepdraft]

I lined the steel tank with sheets of butyl rubber prior to inserting the poly tank... (recommended by ATL).

With all said and done, I’m happy with the result but I’m not sure I’d do it again...

[SpaceRnglr]

Originally Posted by RaymondR

Why not just replace the diesel tank?

The diesel tank will get replaced with a copy of the current tank. Getting access to everything was quite a job so I thought while I am at it i can convert the water tank to get more diesel storage. The I would have 2 diesel tanks good for about 28” litres. Not sure of best practice in the plumbing and hence the question.

[NahanniV]

Originally Posted by Deepdraft

I lined the steel tank with sheets of butyl rubber prior to inserting the poly tank... (recommended by ATL).

With all said and done, I’m happy with the result but I’m not sure I’d do it again...

Cool, I did not know about this option, Thanks for sharing !

Why would you not do it again ?

I'd also be interested to know how much the fuel cell tank cost ?

[Deepdraft]

I may be too old for this crap, but I had more time than money. The thought of a bilge full of diesel left little choice. The prep work involved pumping the existing fuel into barrels for storage in the cockpit, cleaning 1/4 of sludge off the bottom of the tank, then washing down the tank interior prior to cutting the top out piecemeal, (then cutting out the internal baffle). I spent several hours, bent over, with a sazall, and grinder filling the cabin with smoke, sparks, metal dust, broken blades, and spent grinding disks. Once the tank was free of burs, I cleaned it again and started the process of gluing in the butyl sheeting. Each required jury rigged clamping/wedging. Once the new tank was in, I replaced the fill hose, vent line, and deck fitting, ran new feed and return lines, etc.
The tank was $4200, material cost another $300 or so.

[01kiwijohn]

would it not be practical to have a plastic tank welded up? I have a Vetus, plastic, 50 gal tank on the boat I bought and it seems to be doing the job. It stays very clean, won't corrode and doesn't require a fuel gauge as I can put a flashlight on it and see what's in there. (I did put graduated level lines on a tape, applied to the outside, where I can see it from one of the cockpit lockers.)