Diesel Fuel Tank " Sludge "

[David M]

I had the same problem on my boat for a while. In your case, given you have baffles in your fuel tank which make it impossible to scour all the bacteria off the surfaces without actually getting in there, I would add biocide each time you fill up your tanks, buy oversized dual Racors and keep switching over and changing out the filters every time one of them starts drawing too much vacuum.

The dual Racors will allow you to switch filters without having to shut down the engine and will prevent your engine from shutting down while underway provided you notice the increase in vacuum before it is too late. Match the micron size of your large primary filters to your secondary filter so you dont clog your secondary filter....which would require the shutting down of your engine and re-priming of your fuel system...(assuming you dont have a seperate electric priming pump).

The only viable alternative I can think of is to add an access port to your fuel tank so you can manually reach inside and clean all the surfaces that fuel pressure washing cannot get to, and clean it for yourself, but I think that would be more trouble than is necessary.

I think the best solution is to stay on top of the filter changes, get a large dual Racor setup with the 4-way A-B-ALL-OFF valve and over time the problem will gradually go away provided you add biocide each and every time you fuel up.

RACOR 751000MAX2 I have these on my research boat and I am very happy with them. I had to do a rebuild on them because of a very slow drip which basically meant adding new O-rings and seals after about ten years of service but the rebuild was easy and went very quickly.

David

[Nauticatarcher]

If using a fuel additive/Biocide dont use one that puts water into suspension as all it does is increases surface area of water/ fuel interface and will make problem worse, OK if using lots of fuel but not if your fuel sits for a while, you need an additive that kills bug and drops it to bottom of tank and then a way to get it and water out, ie; seperate take off tube that goes all the way to tank bottom or drains in tank bottom

[cat man do]

Originally Posted by David M

I had the same problem on my boat for a while. In your case, given you have baffles in your fuel tank which make it impossible to scour all the bacteria off the surfaces without actually getting in there, I would add biocide each time you fill up your tanks, buy oversized dual Racors and keep switching over and changing out the filters every time one of them starts drawing too much vacuum.

The dual Racors will allow you to switch filters without having to shut down the engine and will prevent your engine from shutting down while underway provided you notice the increase in vacuum before it is too late. Match the micron size of your large primary filters to your secondary filter so you dont clog your secondary filter....which would require the shutting down of your engine and re-priming of your fuel system...(assuming you dont have a seperate electric priming pump).

The only viable alternative I can think of is to add an access port to your fuel tank so you can manually reach inside and clean all the surfaces that fuel pressure washing cannot get to, and clean it for yourself, but I think that would be more trouble than is necessary.

I think the best solution is to stay on top of the filter changes, get a large dual Racor setup with the 4-way A-B-ALL-OFF valve and over time the problem will gradually go away provided you add biocide each and every time you fuel up.

RACOR 751000MAX2 I have these on my research boat and I am very happy with them. I had to do a rebuild on them because of a very slow drip which basically meant adding new O-rings and seals after about ten years of service but the rebuild was easy and went very quickly.

David

Sort of what I was planning on doing.

The pickups are a 12mm fiberglass tube in the lowest part of the underfloor storage tanks (part of epoxy stucture) and these will then have fuel pumped up through a racor 500fg once a day to the Alloy day tank, which will then gravity feed through another 500fg to the motors.

Just above the pickup point in each of the underfloor storage tank (I have 6) I have one of these in black diesel resistant plastic

in the floor (sole) so as to still be able to suck out the majority of sludge figguring that the boat being used, diesel sloshing around it would end up at the lowest part of the hull in each tank.

That, and the use of bocide in every fill, I am hoping will sort any problems out.


Dave

[David M]

Dave,
Sounds like a good plan...just keep working that crap out of there..

David

[cat man do]

Originally Posted by David M

Dave,
Sounds like a good plan...just keep working that crap out of there..

David

Well I havent got any in there at the moment as the boat is a ways off being finished.

I was hoping the biocide would stop anything in its tracks when I do go for the first fill though.

Dave

[David M]

Woops....I spaced.

Sorry Dave

[MitchM]

well on our 30' sloop boat at that time 24 yrs old the origianl fuel tank was galvanized metal, ahd never been pulled otr serviced. . on a rough sea the RACOR started to clog, swapped it out and there was an oily black sludge in the filter. ran out of RACOR filters, eventually got home 11 hrs later. tried to inspect the fuel tank, couldn't see enough of the inside through the ridiculously small inspection port.... dipped an old spatula in attached to a stick, pulled it out -- bottom of the tank was coated with a rusty layer of rusting metal and black goo which was an inch thick in the bottom of the tank. this stuff was getting shaken loose in the heavy pounding we were taking in 10 ft seas to clog the RACOR (what a time for the engine to die!!! of fuel starvation...)
the tank was not salvageable, it had rusted from the inside out . i bought a new stainless steel 13 gallon tank for $200, put in all new fuel lines and new bearing boards and straps to contain and hold down the new tank. took 3 week ends...but i have never had a clogged racor since .. (in fact i sail with 1/2 dz RACORS and secondary fuel filters now.. and am about to install a fuel polishing system so that I can polish the fuel in one tank then run alternate fuel tanks...

[Charlie]

What do you guys think about those polishing systems. I like the idea of cleaner fuel but I don't like the idea of a new system on the boat. More maintainence!!! I think what I'll do is use a Baja type filter and try to keep the tank clean. then once every five years or so I'll open up the access ports and clean the tanks out.

[Oceanside Fuel]

I own a company in Miami called Oceanside Filtration. What we specialize in is the cleaning or polishing of diesel fuel tanks. Boats, generators, fuel storage tanks, anything that has the ability to get this "sludge", we clean. We don't need any fancy tankwork such as cutting holes or getting in and cleaning every inch with paper towels like I read on some of these posts. Using these methods it is almost impossible to reach every baffle in the tank that is full of sludge and often the places you cant see are the worst ones. We use our fuel filtration technology to clean your tank entire tank, including all baffles, and return your fuel cleaner than when purchased. We filter to 0.2 microns, much better than you'll find in most cases. For more information or just to ask a question, we will help you with your fuel problems, without the costly maintenance or lengthy downtime. Contact me by PM for any questions or concerns.

[DeepFrz]

Oceanside Fuel, maybe you could elaborate on how you get the crap from behind a baffle.

[GordMay]

Greetings and welcome aboard the CF, Darren <Oceanside Fuel>.

[SVTatia]

Polishing the fuel and return it to a dirty tank is like taking a bath before jumping into the mud.

I had to open and clean up my tanks by hand twice.
Why?
Know thy fuel!

All it takes is dirty fuel from a filling station and its done. Both of these were outside the States and Canada where the quality is debatable, and there are few if any alternatives.

How do I prevent it now? The Baja filter. The filling stations hate it because it takes so long, but believe me, I have the patience.

[SabreKai]

I'm wondering just how much gunk there will be in tanks that are 50 years old. I picked up two off a boat being scrapped, nice stainless steel tanks with one baffle but no access panels. The boat was built sometime in the 50s, and the tanks were permanent installations.

I'm going to drain them, (they came full of diesel) and then try to get access panels put in and cleaned at the same time.

[DeepFrz]

Good luck SabreKai, I hope the tanks work out for you but I wouldn't think that 50 yr old stainless tanks would have much life left in them. But, I have been wrong from time to time...

[mbianka]

Originally Posted by SabreKai

I'm wondering just how much gunk there will be in tanks that are 50 years old. I picked up two off a boat being scrapped, nice stainless steel tanks with one baffle but no access panels. The boat was built sometime in the 50s, and the tanks were permanent installations.
I'm going to drain them, (they came full of diesel) and then try to get access panels put in and cleaned at the same time.

Don't know about fifty year old tanks but, I can show you what my diesel fuel tank looked liked after twenty five years:
THE BIANKA LOG BLOG: IN THE TANK: Part One, Scene of the grime!
Always used a biocide since I owned her (1995) not sure of the previous owners. Only reason I looked inside is because I'm converting it into a fresh water rinse tank. I converted to electric propulsion in 2008 and don't carry diesel on board anymore. Ignorance was bliss up until that point. It certainly was a yikes moment when I actually had a look inside.