Diesel Fuel Tank Contamination

[Piratenorm]

Morning. My 1983 Mark 1 turned 30 this year. I just returned from a one month tour around Georgian Bay and the last day is one I never want to repeat. Pounding into heavy waves on the last day heading home just a few short hours from home port caused the spooge in the bottom of my diesel tank to clog both my water/fuel separator and the screw on secondary. Thank God she's a sailboat and not a single engine power boat because this happened in a well marked channel of the 30,000 Islands surrounded by boat-eating rocks. I got out of there, swapped out the secondary but 6 hours later it happened again, this was when I found the water/fuel filter not only clogged but damaged.
31 1/2 hours at the wheel criss-crossing Georgian Bay to avoid a series of hugely damaging thunderstorms they never warned me were anything more than 'possible' and no small craft warning, and I managed to sail into a safe anchorage to by-pass the w/f filter, use my last new secondary and regain control for the final trip home.
There is no fuel clean-out panel in the top of the tank, just a 2" dia. hole for the fuel gauge. I imagine I can get a high-pressure pump to suck from there. Has anyone tried a tank clean out on this tank? Is there a junk diluting solvent that I could add to the tank to help get rid of the junk in there?
Believe me, I never want to repeat a night like I experienced. Thanks

 

[Bob S]

Norm,
Sounds like a cruise from hell! Glad you made it, it'll be one of those indelible memories we don't want to remember. I cut a 6" hole on the off season for a clean out port. I leave the tank empty over the winter and in the spring I use a cotton cloth to wipe down the insides. If the residue is too hard you can use a carburetor cleaner to soften it. I'm not sure if polishing your fuel will clean the tank. Maybe someone else might know. I can tell you there is a piece of mind entering each season knowing your tank is clean.

 

[dlewis812]

had similar experience except instead of rocks was worried about barges!

replaced all fuel filters etc and ended up having the marina drain/clean tank. would prefer the $$ to have the marina do in the future. where exactly did you put the drain hole?

thanks

 

[Warren Milberg]

If you have an oldish, OEMish, and cruddish fuel tank, I would look into the economics of just replacing the old tank with a new poly tank. Not sure what the numbers may be, but it may be worthwhile....

 

[jrowan]

The cheapest method is to buy a hand fuel pump from places like Mall wort for around 10 bucks. They sell the same pump at W. Mairne for $40. The old addage, stamp MARINE on it & U can charge 4 times too much for any item. U will find a lot of green sludge at the bottom of your tank that is diesel algae. After pumping it all out & replacing your filters U should be o.k. I did not cut a large port in my tank, because I was afraid of dropping metal shaving into the tank & making more potential future clogs. Unless your tank has visible rust corrosion it does not require replacement. Plastic tanks aren't perfect either, as they can be degraded by fuel corrosion. Be glad U have a diesel engine & not regular gas type with ethanol blend, as it is super corrosive & goes bad after about 6 months!

 

[rgarrison@gmail.com]

The cheapest method is to buy a hand fuel pump from places like Mall wort for around 10 bucks. They sell the same pump at W. Mairne for $40. The old addage, stamp MARINE on it & U can charge 4 times too much for any item. U will find a lot of green sludge at the bottom of your tank that is diesel algae. After pumping it all out & replacing your filters U should be o.k. I did not cut a large port in my tank, because I was afraid of dropping metal shaving into the tank & making more potential future clogs. Unless your tank has visible rust corrosion it does not require replacement. Plastic tanks aren't perfect either, as they can be degraded by fuel corrosion. Be glad U have a diesel engine & not regular gas type with ethanol blend, as it is super corrosive & goes bad after about 6 months!

Wow, I have an Atomic 4 in my older 30, bullet proof engine but I have not heard comment regard "it is super corrosive & goes bad after about 6 months"

Can you expound on that re preventive maintenance?

thx

 

[jrowan]

I won't get into arguments about Atomic 4's, which are indeed a venerable motor, but are getting a little long in the tooth by modern standards. Although I just had a friend across the dock sell his Catalina 30, precisely because he was tired of how unreliable his A 4 was. Diesel engines have been proven to be far more reliable then any gasoline powered engine. My friend sold his, because it was cheaper to sell his C - 30 with an A 4, & buy another C 30 with a newer diesel, then to rip out his worn out A 4 & replace it with a diesel. Diesel engines are proven to be more reliable, more economical, & are inherently less of a fire & explosion risk then gas engines.

I'm surprised that its news to you that ethanol blended gasoline that is required by law, is corrosive to rubber & plastic parts that are prevalent in all engines.
The ethanol & additives like MBTE in gasoline are well known to cause corrosion in marine engines. Look it up in any marine engine trade magazine, or one of the many articles discussing this in Boat US. Don't take my word for it. Listen to experts on marine gas engines. Ethanol blended fuels break down & separate faster, & do not last like traditional blended fuel. Diesel fuel isn't prefect either, as I don't like bio diesel blends for the same reason of phase separation & higher risk of contamination. All fuel breaks down over time when sitting in a boats fuel tank for months, even years. The benefit of an A 4 is that it uses more fuel, so it burns it up faster. My marine diesel fuel tank only holds 12 gallons, & it can take me a year to actually use it up, so it has a tendency to go bad by absorbing water & causing algae growth.

My point was to help Norm find a cheap way to pump out his tank, rather then paying a marina to do what you can do yourself. To those with A 4's that love them, more power to them. But I'm glad that I don't have to worry about the explosion hazards from fumes of gasoline, which is inherently more dangerous, & in my opinion not worth the risk on a sailboat. The reason I say this is because I used to have a sailboat in Deltaville, and a power boat in a marina next door to ours blew up because of gas fumes in its bilge, and destroyed several boats next to it. Its a miracle that no one was killed. All boating has risks, but I try to hedge my bets on what is safer & less risky.

 

[Nahart51]

I just replaced all of my A4 fuel lines with new ethanol compatible lines. Replaced both my fuel filters and rebuilt my carb. Drained my fuel tank.

I also replaced my fuel pump because it was sluggish.

What prompted me to do this was i had starting problems and I found yellow liquid resembling cooking oil in my carb and my fuel lines were swelling and leaking.

Bring aspirin for possible chest pains when you price the hose.

 

[rgarrison@gmail.com]

Is there a way to identify ethanol compatible lines? Perhaps my PO replaced his with the right product

 

[rgarrison@gmail.com]

Thx for your comments, need to live with the issues and try to PM so we are safe.

Randy

 

[FastOlson]

Is there a way to identify ethanol compatible lines? Perhaps my PO replaced his with the right product

Your hose supplier will have nothing but USCG-approved fuel hose on hand. The length of printed stuff/certifications on that hose will be a bunch of letters and some # that will amaze you!

We replaced all the 80's hoses in our boat, some years ago, when I redid the whole diesel fuel system in our boat. The newer hose is impermeable to most everything short of hard radiation!

 

[Allan12210]

Pirate Norm,

Here is a link to my inspection plate installation project from this year. Its not too difficult a task and will allow you access to clean your current tank for a fresh start.

http://hunter.sailboatowners.com/in...mid=267&cat_id=31&aid=8144&page=article&mn=34

I was able to recover my contaminated fuel by pouring it through a filter funnel from West Marine a couple of times. Then I poured it through a 2 micron Racor filter element that I had plugged the threaded hole with a rubber stopper. That way the fuel passed through the pleats. It came out pretty clear on that last pass. I added biocide and put it back into the tank. I made sure it was almost consumed before adding new fuel. Saved on disposal. Now I am using the biocide with every addition of fuel.

Allan

 

[Bob S]

Norm,
I did what Allen did but fabricated the cover myself. I have access to an old engine lathe. It turned out it wasn't that bad but I have piece of mind now. You probably slept for a few days after that! I used a hole saw on an empty tank. The shavings where easy to clean out. you can see pretty good with a flashlight but you have to be somewhat of a contortionist to do anything on a boat. I have used my phone to snap a few pictures to see inside too.

 

[jrowan]

I just replaced all of my A4 fuel lines with new ethanol compatible lines. Replaced both my fuel filters and rebuilt my carb. Drained my fuel tank.

I also replaced my fuel pump because it was sluggish.

What prompted me to do this was i had starting problems and I found yellow liquid resembling cooking oil in my carb and my fuel lines were swelling and leaking.

Bring aspirin for possible chest pains when you price the hose.

Thank you for showing a specific example of what modern ethanol blended gasoline can do to a 30 + year old gas engine that was not designed for the corrosive effects of this fuel. The EPA likely had good intentions by requiring ethanol & MTBE in fuel, but it has a terrible result in marine gas engines. Most car engines meet up with the car crusher after 15 years, but the lifespan of old fiberglass boats & their engines that take 6 months of the year off during the winter means that they could last forever, if not for corrosion from salt water & ethanol!

My sailor friend across the dock also had a weird resin that was building up on the inside walls of all of his fuel lines, & swelling at the fittings & clamps. I thought that it may have just been the age of the hoses & that they were naturally breaking down after 30 + years, but all of the rubber parts in his carb. were gunked up with the same yellow sludge that you describe. MTBE incidentally is also really bad for the environment, not just engines.

 

[Piratenorm]

Thanks very much all, especially who included pictures. This is not going to be a difficult project, I think I'll remove the tank and work on her in the garage over the winter. All is good for now, funny how life repeats itself though. I did a delivery from Trinidad to Ft. Lauderdale 10 years ago of an old Goderich 35 ft. steel hulled sloop and 2 days out of Scotland Bay the engine died as a result of the worst contamination you could imagine. Turns out the boat hadn't been used for anything other than a condo for years and no fuel had been swapped out, despite assurances it had. I had to do a tank cleanout while sailing across the Caribbean so I really should have done one on my own boat, but you all know it's a dirty job that can be easily ignored...with resulting peril. Like Jimmy Buffett says, 'It's My Own Damn Fault.'

 

[Jack - La Paz Mx]

While working on the aluminum diesel tank you might consider the corrosive effects of the water/crud that has been inhabiting the bottom of the tank. Pinhole leaks are the result and a general thinning of the metal. On my '83 I had such a small leak that just had the odor as a warning. Took tank out, flashlight on the bottom, looking in the gauge hole in the dark, found several places where light shone througn (very tiny holes, thin metal). Had it welded, put gasoline in it (suggestion by welder, gas is thinner than diesel), placed upon newspaper, still had leaks. Bought new tank from Catalina.