Fuel tank cleaning

[Beta Don]

I don't know how cork would hold up to the diesel long term if you made the gaskets a full circle where the center is exposed to the diesel - The cork might eventually deteriorate and wind up in the tank

But, if you cut out the center the same size as the hole and bedded it with any sealant rated for use with diesel on both sides of the gasket and squeezed it down with the screws I think it would probably last forever. DON'T OVER TIGHTEN THE SCREWS! Just snug them down equally firm and let the sealant make the seal. You don't want to strip the threads on any of the screws

Don

[smacksman]

My old Seagull has a cork gasket on the fuel shut-off cock. With a 20:1 gas:oil mix it must be close to diesel?

[Beta Don]

Seagulls had cork everywhere . . . . Until a frustrated owner made his own cardboard gaskets trying to get it running again!

Don

[Sprig1]

I have a couple of those seagulls not working. I found some buna nitrile on line seems like the thing to use. 12 x12 x 1/8inch for $9.54. Probably will coat it with permatex perma shield. Thanks for all the help!

[TorreyWP]

Tank cleaning is a bear.

My 72 gallon tank developed pin hole leaks in the aft 1/3. I only noticed when prepping the boat for early launch, installing the aft cabin cushions I found about 3 gallons of diesel fuel that had leaked out over the winter (woof!).

Florida Marine Tanks wants $950 for the identical 72G tank that is in our A27's (single tank setups) plus tax, plus shipping and 6-8 weeks lead time. The best off the shelf options that will fit dimensionally is $500, plastic and only 28G. A local aluminum tank manufacturer wanted $200 to repair my tank so thats the route I have taken.

The welder evaluated the tank internally with a scope before advising that repair was possible. The repair is very professional almost looks like a machine did the welds. A piece of aluminum was welded in half way across the bottom of the tank wrapping up the aft side of the tank a few inches.

A quick cleaning was included in the work but I know he did not clean on the other sides of the baffles as no inspections ports were added. As someone else said, it took 30 years for this tank to develop leaks so Im hoping I can get another 30 out of with conscientious care along the way. I have only owned the boat since last October but have had no filter, high vacuum or water problems but anything can happen. Im lucky this problem happened while being employed at a large scale, full service marina. I was able to pump out the full tank into our various pieces of equipment and have one of our power washing contractors steam clean the tank as best as possible, rinse with diesel all before installing it back in the boat.

Bottom line: tank cleaning is not fun at all and in my opinion, its got to come out of the boat, with or without inspection ports, for a proper clean.

The tank comes out relatively easily through the aft cabin but even empty, its heavy and an awkward shape.

[sail149]

So I was thinking about a fuel scrubbing pump and filter ..now I don't know.( but sounds simpler).
I did read about a guy who built an aluminium sail boat ( his 2nd) for long time 'off the grid.'
He built a day tank for his diesel above the engine ( more room in a sailboat). His thinking was 3 fold.
Minimal risk from dirt as described by smackman but also to keep warm in the Arctic sailing(!) it also allowed him to not use a lift pump, just gravity feed to the engine ( I think he may have used a manual pump to fill the day tank too.)
We used to have the (10 gal) fuel tank under the cotpit of our sailboat gravity feeding the sabb diesel , nice simple system. The engine ran for 4-6 Hours per gal!

[kerrye]

Now you got me thinking.

http://www.ebay.com/itm/8x24-End-Filler ... 1061244707

[Sprig1]

It wasn't to hard to clean or drill the holes. Finding the gasket was the hardest and hopeing it seals is the bad part.I had the boat on a trailer and the through halls out so I just siphoned it out with a long hose from the fuel supply. The only real corrosion is around the little feet. I will use plastic board instead of wood when reinstalling it. There is very minor pitting was thinking about putting Marinetex on it any thoughts? Any ideas on a fuel sender looking at one that is sealed and all electrical is outside the tank.

[kerrye]

One easy way to empty a diesel fuel tank is to disconnect the fuel return line at the tank and run it into a container. Idle the engine and it will pump the fuel into the container.

[Beta Don]

A standard fuel sender should last you a long time. Water in the tank is what makes them go bad

I replaced the original with another just like it and since there was nothing wrong with the original, it and the gauge are now installed in my genset tank

For the engine I installed an electronic gauge. It has a 13 segment LED readout so each bar is about 5 gallons - Makes it easy to know about how many gallons it will take to fill up

Don

[kerrye]

Did some measuring and checking. This 5 gallon tank should fit to the right of the helm seat between the hull and the inner liner. There are two pieces of wood moulded into the hull at that location, I think for mounting the optional diesel heater. Should be able to screw the mounting brackets into those pieces of wood. It's a good out of the way location for a day tank on an A25. A 30x8 might fit in that location as the space extends back behind the seat but it might be tricky getting it in the opening. I'm hoping the 24 x 8 will slide in easier. I'll probably set it up so I can pump fuel into it from the main tank thru the filter but have it gravity feed directly to the engine without going thru the main filter again. There's a bewildering array of different sized aluminum fuel tanks with various options available from this Ebay seller. Amazing. For anyone wanting to add a day tank to any boat, they should have something which would work.

http://www.ebay.com/itm/8x24-END-FILL-S ... 1273394571

[kerrye]

Ended up ordering an 8x26 tank since it had a 1/4" fuel fitting rather than the 3/8" fitting in the tank linked above. I'll report on how feasible it is to install it. I'm thinking T the line from the day tank into the line from the main filter to the engine. Engine will suck from main tank with day tank valve closed and main tank open. Will suck from the day tank with the day tank valve open and main tank closed. I had a primer bulb in the line from the main tank to the filter. Any guess on how long it would take to fill the 5 gallon day tank with the primer bulb? Long enough for it to be worth the effort to install an electric pump?

[JT48348]

A long time.

I'm curious the reason for installing a day tank. I've been thinking about this myself. And I'm not convinced. I'm reading about day tanks from a variety of sources and it seems counter intuitive in the A25/A27 setup.

A day tank is primarily used where you have multiple tanks and/or diesel accessories such as a generator or heater and want to isolate your fuel source or balance your fuel management. They are also sometimes installed in line when you have a main fuel tank that's contaminated or unclean and it's designed to improve reliability like in smacksmans case in rough seas.

You already cleaned your main tank and now have inspection ports. Presumably your fuel filtering is good to go. What purpose does a day tank serve if you don't have any of the above conditions?

In fact you are now adding an extra tank to ultimately service. Extra lines. Extra filters. Extra stuff to go wrong. In addition at 5gal now you have to stop and refil your day tank (by primer bulb?!) every day. Maybe twice?

This seems like making a simple problem more complicated. Cleaning the tank and having inspection ports was tough solution. Why make it more expensive. More complicated. More difficult.

If you have a freshly cleaned tank with inspection ports, new lines & filters you're at a perfect starting point. Manage your fuel well and it's a simple reliable system.

[glk34]

Kerrye, something to think about with the A25 is that if you place the day tank that far starboard will it may affect the balance of the boat? The 25 is a lot more tender than the 27 and we notice when we have extra weight such as extra fuel cans or an extra passenger hanging of the rail (so to speak). Maybe there would be no issue with only 50lbs but it is worth considering. At the least you could store a spare 5 gal container in the port side storage area if space was available. Keep the main tank clean and save your time and money-don't bother with the day tank. Just some thoughts.

Iron Jack

[kerrye]

Yes, there are down sides. I've driven and worked on diesels for about 15 years now. They are pretty simple to diagnose and fix but one important part of the diagnostic procedure is testing the fuel source. Often when facing a problem people will set up a separate fuel supply from the normal one to confirm that everything in the fuel delivery system is functional. With older Mercedes diesels, people will often use soda bottles filled with diesel as the testing tool. With two tanks, particularly one gravity fed, fuel delivery problems, at least to the point where the lines join, can easily be diagnosed. I was sailing with a guy last summer whose diesel engine was intermittent. After quite a bit of diagnostic work on the single supply tank he was able to isolate the problem to a bad connection at his electric fuelpump. If he'd have had even a small separate gravity fed tank, it would have taken him only the time it took to turn three valves to learn that the problem was in the fuel delivery system from the main tank.