Fuel Smell

[JPA Cate]

Some years back, we had a diesel fuel leak from the forward outboard corner of the aluminum fuel tank, the lowest of the 4 bottom corners. It was due to a "pinhole" weep. To fix it, Jim took the tin snips and cut a patch out of an aluminum beer can, and epoxied it over like a bandage. At the time, he told me that since the diesel floats on water, he believed the weep-hole was due to the water which condenses in the tank interacting with the with the aluminum. The fix lasted as long as we owned the boat.

To me, the smell from a stale shower water sump and a diesel leak are very different: one smells like fuel, the other like sewage.

I wonder if the OP has two different things going on concurrently?

Ann

[Teknav]

...ummm...where's Roto Rooter for sail boats when you need him? Mauritz

[Kettlewell]

To me, the smell from a stale shower water sump and a diesel leak are very different: one smells like fuel, the other like sewage.

One thing I have learned is that different people perceive smells different ways. I have been on some boats where I could barely stand to stay below they smelled so bad, while obviously the owners were oblivious. I once was looking seriously at a boat for sale, to the point I went on a test sail, but once things started sloshing around the diesel and sewage smells were so intense I felt ill. I later quietly asked my wife what she thought and she said we could never buy that boat, it was too stinky.

[Capt Phil]

Boat odors are the bane of live aboards, whether deisel or shower sumps or bilges. All require the nose of a sleuth, the persistence of a bird dog and the patience of Job. I've been where Ann T.'s husband has been and found a pin hole leak that was really difficult to fix but got her done. Tanks were black iron as I recall which required disconnection, draining, lifting tank up and welding on patch before reseating the tank and testing not cheap or easy to do.
Stinky bilges require complete cleaning, drying, repainting with 2 part epoxy paint and constant maintenance to keep clean and dry.
Shower sump, same as bilges... clean regularly, at least every 3 days, clean strainers, wipe out excess water not pumped out and rinse with SuperGreen or similar environmentally friendly disinfectant.
If using your boat only occasionally, clean after every use otherwise you end up with that ugly smell whenever you open the hatch. It will invade your soft goods like bedding, clothes and cushions and is almost impossible to get rid of one established. My wife used to call it 'boat smell' and you could smell it on each other when we were out for an evening. Lived aboard for many years and learned a lot about odor and how to minimize it. Phil

[JPA Cate]

Phil,

Good regime! but instead of "Super Green", we wipe out with plain white vinegar. Guess it depends on what kind of lingering smell you like. For me, something that reminds me of salad is good. ;-)

A

[Capt Phil]

Thanks, Ann T... I find that vinegar reminds me of fish and chips and not a good smell when I'm trying to avoid greasy food! My wife loves to use vinegar and water solution for cleaning floors, counters, etc but I drew the line at using it to clean bilges and sumps. I misspoke in my previous note... I should have said Simple Green, not Super Green.
I have heard that using bleach or even a water/bleach solution can be very hard on hoses, pump impellers and other parts as well as not to friendly to the environment. Cheers, Phil

[Tayana42]

I also had a pin hole leak in a black iron fuel tank. Too small to see the leak and my wife smelled it before diesel sheen was obvious in the bilge. Tank was under all the galley cabinetry and parts of the floor without access. We couldn't get the tank out without tearing up the entire cabin or cutting a 4 foot by 6 foot hole one the side of the hull. So instead we cut a larger access port in the top of the tank, cut out and ground smooth the baffles, and had a custom aircraft quality flexible tank made to fit inside of the old tank. 7 years on it now and so far so good.

[Kettlewell]

Could be a pin hole leak in the tank, but consider replacing those hoses or at least checking more carefully first. After awhile they harden up and don't seal properly, even if they look fine visually.

[cal 39 guy]

Thanks to all for advise!
girlfriend has abandoned ship due to stink fiesta
after major bilge clean, the smell is a lot better but i can still smell diesel.
i think ann was right i have a stink combo going on.
i cut an access hole in wood on top of tank to get a visual.
its a 90 gal aluminum tank with three large circular inspection ports.
i can smell strong diesel fumes around tank but no sign of weeping tank
except a little black color around sending unit. i did find a hose that has cracks when i bend it: so thats my next move to replace.

[cal 39 guy]

filler hose is in two parts. found cracks in one hose. i think its the return hose from injector pump.
also don't see any sheen in bilge water.

[cal 39 guy]

Do i need to worry about having to bleed engine fuel system after replacing hoses. if so, anyway to avoid this?

also my shop manual doesn't show the fuel water separator thats mounted to bulkhead. Does fuel tank outlet go to water separator then to lift pump then to final filter then to
ejection pump? and what route does fuel take to return to tank. (perkins 4108)

[Kettlewell]

Do i need to worry about having to bleed engine fuel system after replacing hoses. if so, anyway to avoid this?

also my shop manual doesn't show the fuel water separator thats mounted to bulkhead. Does fuel tank outlet go to water separator then to lift pump then to final filter then to
ejection pump? and what route does fuel take to return to tank. (perkins 4108)

You will only have to bleed engine if you remove or replace the fuel line that runs from the tank to the fuel/water separator. From the separator the fuel goes to the lift pump, then to the final filter (usually on engine), than to the injection pump. I'm not sure, but I believe the return line on the 4.108 goes directly back to the fuel tank. You don't have to worry about air in the fuel return line. You should be able to see several fittings on top of your fuel tank. The biggest one is the fuel fill line. The next biggest should be the tank vent line. The next size down is probably the fuel supply to the engine, and the smallest should be the fuel return line.

[cal 39 guy]

the line thats cracking is smallest line. there are two with flared fitting
one has the shut off
other one is cracked one, does that sound like return line?

and if so where should i look for other end?

the lines from tank go out of site after a few feet.
whats the best way to trace where they go?

oh can i use fuel line from napa or should i get from marine store?

[Kettlewell]

I think you are on the right track. The line with the shut off valve is your main feed that goes to the fuel filter and then the engine. The return line should be the other one, which is smaller. Its other end will be on the engine at a pipe coming off of the injectors. Diesel fuel line is diesel fuel line, but make sure you get hose at NAPA that is rated for diesel.

[cal 39 guy]

ok i found the other end of cracked fuel return line at top of final filer. but the hose is crimped to flair fitting. On tank end the hose uses hose clamp to attach to flair.
can i buy a flair to barb fitting to replace hose. And if so what angle flair fitting?