Polishing diesel fuel and cleaning fuel tank

[Sea Hunt]

A friend here in Miami needs to have their fuel tank cleaned and the diesel fuel polished.

Does anyone have a recommendation for a reputable company that will perform those services on a 25-30 gallon tank

Thanks in advance for any suggestions or recommendations.

[tartansailor]

Pump the diesel through a 0.3 micron filter designed for organic fluids.

As for the tank, pull it, throw in some clean heavy chain, and shake & rotate.

Flush out thoroughly.

Dick

[Sea Hunt]

Hello Dick:

Thanks for recommendation. I will pass it on.

I think this person is looking for a professional fuel/tank cleaning service to make sure the old fuel (and new fuel when added) is very clean and does not clog up the injection ports, fuel lines, filter, etc.

[Troy Scott]

Sea Hunt,

Has your friend looked inside the tank? We cleaned the tank on my CD36 without removing it from the boat. We removed the fuel gauge and the inspection plate. We siphoned the old fuel out into new plastic garbage cans. This worked easily because the boat was on the hard Otherwise we could have used an inexpensive pump to do the same thing. We filtered the diesel through tee-shirt material, removing quite a lot of material that looked like used coffee grounds. This material is typical of diesel tank contamination. We chose not to keep the fuel because if was fairly old. I suppose we could have polished it, but it would still have been old.....

Back to the tank: In the "empty" tank we could easily see more of the "coffee grounds" junk on the floor and stuck to the walls. A little experimenting revealed that mineral spirits would dissolve most of the gunk with little difficulty. We poured several gallons in the tank. We taped one inch chip brushes to long wooden dowels and used them to attack the remaining deposits that we could reach. Of course the baffles kept us from reaching everything. We would occasionally siphon out the contaminated mineral spirits, filter it through tee-shirt cloth, and return it to the tank. Eventually all that was left were a few deposits we could see with the mirror but couldn't attack with the brush. At that point I bought a pump-up garden sprayer with a bendable, flexible wand. We used it to blow off the remainder of the junk. We were able to get the tank very clean, with the exception of a few well attached varnish-like areas.

While I had the fuel gauge out I resealed the dried cork float with new epoxy resin.

[John Danicic]

Troy or any one that might know.

What is that flaky stuff in diesel tanks and how does it form.

I drained this out of my fuel filter so it is light enough to get a moving through the fuel lines.
Any ideas out there?




Sail on

John Danicic

CD36 - Mariah- #124
Lake Superior- The Apostle Islands

[Jim Davis]

And ultimately commercial. I have no desire to start another Alge-X thread, but the description of how diesel breaks down is good. It shows the need to drain off water and know how to service your own filters.
http://www.diesel-fuels.com/bad-diesel-fuel.php

As a practical mater I have two Racor's hooked up to a manifold, so if one fails (clogged or water) I can shift filters in seconds. Then wait till I am anchored to service the "bad one". Normally just bleed the water picked up at the last refueling.

[Maine Sail]

John,

That looks like a diesel fungus that was treated with a biocide. One of the most common is C. Resinae. The biocides tend to kill off the fungi or bacteria and then leave that residue behind which can plug a filter.

Sadly fuel polishing DOES NOT clean fuel tanks and really is a waste of money IMHO unless you really must spend $300.00 ta save that 14 gallons of fuel.

The residue that gets on tank walls, and hides behind baffles, needs to be scrubbed clean or be given a chemical bath. I would strongly advise against the use of chains in tanks as even a small piece of dissimilar metal in the bottom of an aluminum tank can wreak havoc galvanically.

You will be far better off in the long run to physically clean your tank. Below is a photo of a tank that had been "polished" and "cleaned" five years prior to the photo being taken. After cleaning it was fed a ritual of biocide & SolTron/Startron and the remaining fuel removed and burned in a furnace at the end of each season.

It is a false economy IMHO to spend $200.00-$300.00 to save 10-20 gallons of fuel. You really get no benefit other than that and the polishing can actually churn up more crud that will later plug filters than it can catch.

Tank wall sludge:



Inside the tank:





How I dealt with the issue on my own vessel:

#1 New tank

#2 Permanently installed fuel polishing system from day one with its own supply & return tappings

#3 Polishing system pick up 1/8" from the absolute low spot in the tank

#4 Polishing system runs when ever the engine runs and turns the tank over at a rate of 72 GPH

#5 Polishing return is fed into a separate compartment and returned below the level of fuel to avoid foaming.

#6 Racor 900 filter was used to accommodate capacity of 72GPH pump and to have more filter media.

Tapping and dip tube layout:


Final installation:



I spent only $96.00 more for this permanently installed always polishing system than the PO spend on a one time fuel polishing. The whole system cost me under $400.00....

P.S. Fuel is still treated with a biocide, Startron and a cetane booster..

[Troy Scott]

John,

Maine Sail is right, of course. What you have there is a bunch of dead bodies in various stages of decay. There is, native to this planet, a life-form that thrives in diesel fuel. It's commonly found in most tanks that aren't really, really new. Ideally a biocide for treating diesel in a tank would kill and DISSOLVE the little critters. To my knowledge, none of them do..., so you just swap one problem for another. You have dead stuff that you must filter out, instead of live stuff that you must filter out.

[tartansailor]

John,


I would strongly advise against the use of chains in tanks as even a small piece of dissimilar metal in the bottom of an aluminum tank can wreak havoc galvanically.

So Aluminum is going to abrade steel!

[Maine Sail]

John,


I would strongly advise against the use of chains in tanks as even a small piece of dissimilar metal in the bottom of an aluminum tank can wreak havoc galvanically.

So Aluminum is going to abrade steel!

Not likely.

My point is that when chain tumbles it sheds little pieces of steel etc. etc.. all one needs to do is go to a store with brand new chain and unload 30 feet onto a clean floor then put it back. You'll find lots of metallic debris remaining on the floor after you put the chain away. Also aluminum is soft and any surface scratches inside the tank can become the beginning of a poltice corrosion spot...

Any dissimilar metal that is higher on the galvanic scale will become the noble metal and the aluminum the anodic metal.

This hole was caused by a piece of dissimilar metal that at one point, perhaps during a sending unit change out, found its way to the bottom of the tank where it embedded in some tank sludge and ate a hole..

[John Danicic]

Well, that is interesting.


Since this will be an ongoing problem, it seems to me the best thing to do with out going the expensive, time consuming route of MaineSail and his new tank/fuel polisher system, is to install a fuel polishing system on the existing tank and keep the filters, all the filters regularly changed. That and not allowing the tank to get too low on fuel should keep Mr. Perkins running for a few more thousand hours.

Also, vowing to sail more and motor less would help as well.

MaineSail, your tank photo indicating the locations of the intake and outlet lines is an excellent illustration of how to proceed with the most important step of installing the fuel polishing system. The old tank photos were pretty cool as well. I can only imagine what my 26 year old tank looks like. Thanks for being so visual in your explanations.




Sail on

John Danicic

CD36 - Mariah- #124
Lake Superior- The Apostle Islands

[Zeida]

Hi all...

First, I'm most thankful to Sea Hunt who took the time to graciously post the inquiry on my behalf. He went sailing with me on Bandolera II, a CD-33 a couple of weeks ago and as we were almost back at my slip, the engine just stopped and would not start again. We were towed in.

Upon inspection, when opening the top of the Racor filter, we saw there was not enough fuel in there... obviously, something went wrong along the fuel lines. Clogged, or crud from the tank, etc. A couple of days later, I cleaned up Racor as well as I could, replaced the filter which was absolutely full of junk, filled it up with new fuel. I also replaced the secondary fuel filter, cleaned the electric fuel pump. Then bled the system. My engine started again fine. However, since I have owned the boat-12 yrs. now, I have never cleaned that fuel tank... neither the PO. So I can only imagine what can be in there. I did not want to start my engine again without trying to do something about the fuel in that tank and trying to somehow clean it, if possible.

Yes, I got quotes from $350 to $400. for "fuel polishing". BUT... the fuel tank on my 33 is in an impossible access place. I guess that to take it out, it would have to be cut up in place in order to remove it in pieces through the access in the port cockpit locker. The fuel access is via the stbd. locker, through a small cap opening, in a small glassed-in shelf, and only a measuring stick fits in there. To fuel up, I insert a small funnel and filter the new fuel I put in. It carries 20 gals. of fuel. It does not have any type of fuel gage or anything. Just, on top of the tank, one small "out" for the main fuel line that goes directly to the electric fuel pump (from there to the Racor..etc.) - another small "vent" hose that leads all the way to the stern - and a small "return" line from the injectors. These small outlets are almost impossible to reach, unless you are willing to really scratch your hands big time (which I do anyway).

After looking at Maine Sail's set-up I am green with envy. My boat lives in the water all year round. I do not have a work area such as his, much less the ability to do such things. If I were to replace my tank with a new one, it would become a task for myself and a plumber doing it together in order to make the project affordable. Actually, the more I think about it, the more possible the project looks.

Any recommendations would be extremely welcome. I will take photos today of my situation and post them for advise. Thanks.

[Maine Sail]

Zeida,

Fuel polishing won't hurt anything but your wallet but, as I mentioned, won't actually clean the tank, walls etc. something folks seem to think it will do. The problem with most tanks is that the pick up tube only goes within about 1- 1 1/2" to the bottom so you really never pick up the living debris accumulated on the bottom of the tank.

Even high pressure polishing can not always get this stuff as baffles can get in the way.

Tanks can sometimes be cleaned in place by installing clean out plates but it sounds like your only option, for now, is to either drain and re-fill or make an attempt at polishing. Just be aware that you may have a couple of plugged filters right after a polishing. Use a 30 micron for a while then when all seems well it will be okay to use a 10 micron primary. I would NOT advise the use of a 2 micron as a primary filter..

You may also have a screen on the pick up tube in the tank, many builders did this and it was rather ludicrous as they can plug and no matter how many filter changes you do you can't fix it until you remove the screen...

BTW my tank was NOT easy to get out and I had to pull the engine to do so and your envy was for not. If you ever do need to replace a tank that will be the time to rethink the design and layout, as I did..

[bottomscraper]

Also, vowing to sail more and motor less would help as well.

Actually I think if you motor more and sail less you would have less
problems. Overall your fuel would not be as old and the extra fuel
from the return line is filtered and heated. For what it's worth that's
my thinking.

From all the stories I read it seems the sailors who don't use thier
engines much have the most problems.

[tartansailor]

John,


This hole was caused by a piece of dissimilar metal that at one point, perhaps during a sending unit change out, found its way to the bottom of the tank where it embedded in some tank sludge and ate a hole..

How do you know that it was caused by a chain particle, and not something from the fuel distillation column down through the distribution system? And how do you know that it was metal
in the first place??