Diesel Fuel Tank " Sludge "

[Journey41]

Hello --

This is bit lengthy...sorry!

I was recently motoring (no wind!) and my engine started to die. Did
die, actually. I switched fuel tanks and switched Racor filters and
was on my way. After returning to port, I found that one of my
primary filters was clogged (obviously). I replaced the element and,
not knowing much of anything about diesel fuel, called a fuel
polishing service.

The fuel was polished and some dark, solid contaminates were
eliminated (no water at all). However, upon looking inside both
tanks through the 6" inspection holes, I saw that the inside of my
port side tank (inner surface, not the fuel itself) was completly black with some type of film that I
could scrape off with my fingernail. This was the tank that I do not
use (since I've had the boat - 1.5 years - I have always drawn fuel
from my stbd tank and had the excess return fuel go to my port
tank). Looking at my stbd tank - the one that I use - it was MUCH
cleaner, although there was some splotchy black areas. There was
nothing floating around in either tank that could be seen and the
fuel looked great - all the black film was stuck to the sides. So,
the nice fuel polisher man put some type of additive in my tanks
after the polish.

Fast forward a week. I started my engine and saw that the vacuum
guage on top of my primary filter started to rise. More of the black
solids clogged my filter.

From some research I have subsequently done, I have learned that the
black film/sludge on the inside of my tanks is probably
diesel "algae." I'm assumming that my port tank was much worse
because I did not use that fuel and it has been sitting for who
knows how long. I'm guessing that the additive that the nice fuel
polish man put in started to break up some of the tank algae,
resulting in the litlle bastards swimming freely in my tanks and
then being sucked into my primary filters.

Now to my question...

Has anyone had experience with fuel additives (such as the Algae-X
AFC-705) that can supposedly be added and that will break down all
of the sludge without having to take out all of the fuel and clean
the tanks? Or, as I was told by a local fuel service at the marina,
I can bring the boat to them and they will --

1. remove all fuel and put in external tank
2. go in through the inspection plates and spray some type of
chemical to remove the sludge and clean the inside of the tanks
3. return the fuel to the tanks (after it has been fully polished)

What I'm not getting is how all of the sludge can be taken out as my
tanks have baffles (like me...or that would be baffled). And the
inspection ports are on one end of my tank where the fuel is drawn
up...there is no access to the other parts of the tank (which are
under the cabin sole and I have no idea how to access).

My tank seems to be one tank (don't know the size, but I think it's 200 gallons total) but split into 2 sides with 2 different fill
holes (although only one deck fill...seems strange as there is no
way to regulate which tank the fuel goes into. But that's another
issue).

Does anyone have any sage advice or experience with something like
this?

Thanks

John
Islander Freeport 41
"Journey"

[DeepFrz]

Your tanks need to be cleaned. I have had the same problem where the engine stopped in a seaway. Not fun. It will be expensive and I don't have any advice on how best to get to all areas of your tank, but leaving that stuff in there is just asking for more trouble. Tough to say how best to do it without seeing it. The stuff I had actually clogged the fuel line. Didn't even make it to the filter.

[Celestialsailor]

Did they look a little like this? Many threads address what you are asking. And you're right...How can they clean behind baffles...they can't!
I once used a product called VALVTEC for the algae. It attacked the copper draw tube and they ignored my phone calls. Research it well!

[Charlie]

I just finished cleaning one of my tanks. It was a PITA. I had to pull the cabin sole up and then cut holes in my tanks and then put the access ports in. The actual cleaning of the tank I used paper towels srayed with non amonia window cleaner. I then hit any spots that didn't look clean with Scotch Brite pads and again used the paper towels. The sludge comes up pretty easy with a scraper. I'm sure it would cost a fortune to hire it done. I have to do the Port tank next.

[Inthewind]

Depending on the degree of contamination it may be nessasary to cut access holes in the tank to gain access. No fuel polisher is going to get 100% of contamination out, however they will dramatically reduce the amount of contamination. The machine that I use pulls the fuel out using a series of filters, then shoots it back in the tank under high pressure washing the inside of the tank. I am constantly moving the wands inside the tank and under the baffles and also changing the direction of the fuel rotation inside the tank. I generally know when fuel is clean by examining the filters that my machine uses. I will not stop until my filters are 100% clean and I am confident that problems will not arrise for a long time.

Generally, I will tell the customer to add a fuel biocide a few days before I arrive with my equipment. Another words kill the bacteria and loosen it up from the tank before polishing. Adding it after polishing is just going to cause problems with clogging filters as the comtamination lets loose and gets suspended in the fuel. I give a 6 month guarantee that I will come back if problems arrise from clogging filters.

It sounds to me that the polishing service that you used needs to come back out and polish your fuel again as he did not fix your problem. If it were me I would not want to get a bad reputation from unfinished work. Alot of my work is word of mouth from customers that are happy with my service and they know I stand behind my work.

[Celestialsailor]

I can't see how fuel polishing is going to remove the sludge from the sides and top of the tank or around the baffles. When the boat is in a rough seaway, the diesel sloshing around in the tank loosens that sludge and then clogs the filters.

[DeepFrz]

John, you are not the first person I have heard of who had their fuel cleaned but the contractor did not clean the tank. They had trouble, just as you have, shortly afterwards and ended up having to have access ports put into their tanks and tanks cleaned. It's a real PITA, but there really are no shortcuts.

[GordMay]

A proper fuel polishing returns the fuel to tank under high pressure, which scours the interior of the tank (with varying success, depending upon the specific geometries).

[migot1]

you should clean the tank with scotcbrite and clean fuel. not soap. plenty of rags to mop it all. hard work...no shortcuts...

[cat man do]

Originally Posted by migot1

you should clean the tank with scotcbrite and clean fuel. not soap. plenty of rags to mop it all. hard work...no shortcuts...

And if tanks are underfloor with probably 20 or 30 seperete baffled compartments?

Would using a Biocide from day 1 and adding with every fill or partial fill stop the problem from starting in the first place ?


Dave

[Journey41]

I see that my sludge problem is quite a bummer. I'm opting with a service that uses high pressure and a special, flexible hose (along with the polishing). They come to me and guarantee their results...quite pricey (think chartplotter), but they say they will take care of the issue or I pay nothing. Plus they come to my boat. Sounds good to me...

I appreciate all of the info from everyone.

John

[GordMay]

You can often negotiate a discount, if there are several boats on adjacent (or very nearby) docks participating.
Travel & set-up time are a significant part of a mobile service’s cost.

I think that the cost of 3 boats was only about double the cost of doing 1, last I had it done. This represented a 1/3 discount for each of us.

[Inthewind]

The use of Biocide will keep bateria from forming. You could also dip your tanks with water finding paste (Kolor Kut), it will turn red up to the level of water in your tanks. The bacteria thrives with water and oxigen. Water is heavier than diesel and stay's on the bottom of the tank and that is where bacteria forms. Removing the water decreases the ability of bacteria to form. Also keeping tanks topped off if you leave the boat for extended periods of time helps.

As for people wanting to manually clean their tanks,that's great if you can do it. Alot of fuel tanks are built into the boats in impossible places to access the whole tank. Diesel fuel polishing is a viable option to remove most of the contamination and to bring it down to a managable level. The machine that I use actually agitates the fuel as much or more than being in adverse sea conditions. High pressure causes the contamination to break free from clinging to the bottom and sides of the tank at the same time sucking it up and filtering it out.

Also you want to be careful where you get your fuel, you want to make shure the storage tank has a filter system on it before it enters your boat as people have unknowingly put contaminated fuel in thier vessel. A filtered funnel can help prevent this from happening.

I believe in using the biggest filters that you can fit in your engine room. The bigger the filter, the longer it takes to clog up, (Racor 1000's) if possible and always carry spare filters.

Diesel fuel contamination is a problem that has plagued a tremendous amount of fuel tanks around the world. I understand the fuel companies are adding biocide to fuel now to cut down on this problem. I think they are trying to put me out of bussiness.LOL

[Tropic Cat]

Slug is a constant battle in my fuel tanks. To date, I haven't found anythng that works. I add fuel conditioner and a biocide each time I take on fuel. Regardless, 3 to 4 months later, I have problems.

I wonder if this is warm climate issue?

[imagine2frolic]

I am in Jax Florida. The only problem with sludge I ever had was in Miami. Thatmorning I was changing the oil to prepare for destination Jax. I looked in the tanks, and the bowl of both filters. Everything was as pretty as a ruby. By the time I was just north of the Cape 1 motor died.

We sailed into Ponce inlet, and started working on the system. All lines were plugged with not only sludge, but bits of paper too. Got the tank out, cleaned, and the motor running. Started the second engine, and it plugged too. A week in the engine compartments with my wife pulling both tanks.

My thinking is that Miami was at the bottom of it's tanks when we filled. That was 4 years ago, and not a problem since.....knock on wood....me head!