Fuel polishing - how often?

[valhalla360]

1) If a concern, filter before adding to the tank. What doesn't get in can't accumulate in the bottom corners.
2) Don't store fuel for long periods of time. Use it.
3) Look for a boat with good access to the tank. Even better a tank that can be removed (we have 2 and they can be removed in about an hour. Friends with the same boat have taken thiers to the car wash and power washed them, dried them and put them back in.)

[Kenomac]

Originally Posted by valhalla360

1) If a concern, filter before adding to the tank. What doesn't get in can't accumulate in the bottom corners.

The sludge actually grows somehow from fuel breaking down and the water separating out, or water entering via the fill cap. The sludge is not something that can be pre filtered. Believe it or not, there are actually mico organisms that live in the water that accumulates at the bottom of the tank and feed off the fuel... creating the sludge.

But you are correct that pre filtering is a good idea in preventing a filling station from selling you a tank of fuel filled with the sludge from the bottom of their tank. But it can also grow in your tank.

[valhalla360]

Originally Posted by Kenomac

The sludge actually grows somehow from fuel breaking down and the water separating out, or water entering via the fill cap. The sludge is not something that can be pre filtered. Believe it or not, there are actually mico organisms that live in the water that accumulates at the bottom of the tank and feed off the fuel... creating the sludge.

But you are correct that pre filtering is a good idea in preventing a filling station from selling you a tank of fuel filled with the sludge from the bottom of their tank. But it can also grow in your tank.

I should have clarified, use a water seperating filter.

If your tanks are leaking (and I believe this is where most water issues come from, not condensation), fix the leak.

Those critters primarily live at the interface between the water and fuel (dead ones sink and become sludge). Take away the water and they have no place to live.

[Toys_with_time]

Originally Posted by Muckle Flugga

Yes. For bacteria. Actually the most useful bit of my particular filter.

Commercially available or do you have to build your own?

[Dockhead]

Originally Posted by s/v Jedi

When you recirculate fuel in the same tank the rule of thumb is to pump an amount of fuel 5 times that of the tank contents for a full polishing cycle.

I have a sump welded under my aluminium fuel tanks and pick up the fuel from there. If you don't have that, you need a separate pickup-tube that goes all the way down to the bottom. Many attach a small piece of hose that is an inch or two too long so that it bends to horizontal right on the tank bottom.
For storage I add the enzyme based StarTron and circulate through every filter and engine. You see the color change. When done, you can leave it for a long time, I did for up to 8 months and never a problem.

The picture with the crud on the tank bottom: use a pressure washer that is fed with diesel instead of water. This is how commercial polishers do it.

Or just hire the commercial polisher

That's what I do.

In my opinion, whatever you do, whether you have your own polishing system or not, you've got to open up the tanks on a regular basis, get a good look at the insides of them, and physically clean them. Not doing that -- relying on chemicals or filters and just guessing that the tanks are clean inside -- is asking for trouble, in my opinion.

[Dockhead]

Originally Posted by Kenomac

The sludge actually grows somehow from fuel breaking down and the water separating out, or water entering via the fill cap. The sludge is not something that can be pre filtered. Believe it or not, there are actually mico organisms that live in the water that accumulates at the bottom of the tank and feed off the fuel... creating the sludge.
.

That's correct. The sludge is formed inside the tank, so "what doesn't get in" CAN and DOES accumulate inside the tank.

[Kenomac]

Originally Posted by Dockhead

Or just hire the commercial polisher

That's what I do.

In my opinion, whatever you do, whether you have your own polishing system or not, you've got to open up the tanks on a regular basis, get a good look at the insides of them, and physically clean them. Not doing that -- relying on chemicals or filters and just guessing that the tanks are clean inside -- is asking for trouble, in my opinion.

When you have your own polisher and run it on a regular basis, there's no need to clean your tanks on a regular schedule or hire the commercial polisher. Because there's no sludge to clean. Plus.... with your own unit, you're protected year round. Relying on your method, you're unprotected in between commercial polishing and clean outs.

[Dockhead]

Originally Posted by Kenomac

When you have your own polisher and run it on a regular basis, there's no need to clean your tanks on a regular schedule or hire the commercial polisher. Because there's no sludge to clean. Plus.... with your own unit, you're protected year round. Relying on your method, you're unprotected in between commercial polishing and clean outs.

Well, even with an on-board polishing system, I would strongly recommend that you open up and inspect your tanks on a regular basis. As others have said, a polishing system, however great it is, is not a silver bullet. If there's really nothing in there for sure, then I guess you could forgo the cleaning (I wouldn't, though). The difference between a pro polisher and your onboard system is that the pro actually pressure washes the inside of the tank, physically cleaning it. I've never had any sludge in my tanks, nor even a drop of water, but I still do this every two years as preventative maintenance.

Also I pop the top off my tank at least once a year and peer into it with a flashlight. On my boat, it's somewhat hard to get to, requiring removal of the built-in microwave, but it's an hour well spent. The tank has a sump directly below the inspection hatch, so once you've got it open, it's easy to do. I think about putting a dip tube in there (there's a free port) for drawing out samples from the bottom of the sump without removing the microwave, which would make it practical to do it much more often. Probably a good idea, but this has lingered low on my list since I've not had any water or sludge anyway. I'm going to be installing an ultrasonic tank level sensor soon, so maybe I'll put in the dip tube then. Hmmm.

I would do all the same even if I had an on-board polishing system. It's a great thing to have, I'm sure, but I would not rely on it as a substitute for regular inspection and cleaning.

[Xlantic]

A problem with professional polishing or even simply inspecting the tanks is that tanks usually have internal baffles that limit the access inside the tank, even if there is an inspection port.

This was my case so my solution was to install day tanks 5 years ago. The day tanks are filled before cruising with freshly filtered and de-watered fuel from the tanks, and filtered again on the way to the engine. If the boat has been unused for a while, I empty the day tanks to the main tanks and then refill. The day tanks have a sump from where i can withdraw any water or sediment that could accumulate although none has to date.

[Muckle Flugga]

Originally Posted by valhalla360

I should have clarified, use a water seperating filter.

If your tanks are leaking (and I believe this is where most water issues come from, not condensation), fix the leak.

Those critters primarily live at the interface between the water and fuel (dead ones sink and become sludge). Take away the water and they have no place to live.

Well thats a nice idea. Also take away any air will help too… except that is not possible, unless you vent your tanks to a dynamic inert gas system… so no. Your tanks have vents… to the outside air. Air contains significant quantities of water. Condensation may be a lesser issue than filling your tanks directly wtih water, but it is absolutely still an issue. And by the way I do use a water filter for every drop going into the tanks. I have very little water in my tanks at any point, imperceptible in fact, but sludge is still an issue from time to time, as my perception and that of bacteria differ. Also, of course, there is simply the issue of dirty fuel, as in fuels that have been transported or kept in containers with other compounds and contaminants. This is very common in the 3rd world. The prefilters for filling purposes and water separation are very large mesh (or else it would take a crazy amount of time to fill your tanks). They let almost everything but (most of) the water through, and almost everything else of significance...

There is no substitute for secondary pre filtration. And a polisher helps for sure.

[Muckle Flugga]

Originally Posted by Toys_with_time

Commercially available or do you have to build your own?

Commercial. Was part of the system. Mad in NZ. I am currently travelling and away from the boat so I have not got the data to hand.

[weavis]

Originally Posted by Dockhead

Also I pop the top off my tank at least once a year and peer into it with a flashlight.

I could not find my glasses in the desk so read this post with Angelas glasses.

Why would Dockhead pee into his diesel tank? Why does he need a flashlight to do it?

Found my glasses. For a moment there I thought Dockie had a cleaning technique I had not heard of. More worried about the clinical ramifications of needing flashlight assistance to pee........

Glad that is cleared up.

[weavis]

Originally Posted by Kenomac

When you have your own polisher and run it on a regular basis, there's no need to clean your tanks on a regular schedule or hire the commercial polisher. Because there's no sludge to clean. Plus.... with your own unit, you're protected year round. Relying on your method, you're unprotected in between commercial polishing and clean outs.

Im not sure I can agree fully with this statement. A polisher cleans diesel not tanks. If a poor quality diesel is pumped aboard, and filters have to be changed, there is a chance nasties can start to work in your tank. You need to start with a clean tank. Now, in agreement with your statement, the odds are lessened considerably, however-you will never be sure if you dont look.

Given that you store your vessel for months at time, I would really really suggest popping the top and taking a look on your return and before sailing. JUST IN CASE.

Your probably right Ken, however I would hate to be right and you find out in a seaway that I was. For the sake of a look its not worth assuming.

For the record, I never had a diesel up till this last four years, and have had the fuel polished and two tanks inspected. One was ok and the other was sludged. Petrol has its own issues...... left for a long time it becomes KaKa.

[Kenomac]

Originally Posted by weavis

Im not sure I can agree fully with this statement. A polisher cleans diesel not tanks. If a poor quality diesel is pumped aboard, and filters have to be changed, there is a chance nasties can start to work in your tank. You need to start with a clean tank.
Given that you store your vessel for months at time, I would really really suggest popping the top and taking a look on your return and before sailing. JUST IN CASE.

Weavis and Dockhead,

I check my tanks via two clear plastic chamber lids that measure 12 inches across. It's easy to do, only takes a minute. There's isn't any crud in the tanks due to my use of the initial screening filter funnel I use when filling, and the the subsequent polishing. Even if I had a partial blockage (which is so unlikely that it's probably statistically impossible) I can always switch over to the second Racor filter in about..... 1-2 seconds giving me a brand new filter.

Forget about the professional cleaners, just dump any bad fuel like I did two years ago, give the tank a good cleaning, then install a high quality polishing system which runs separate from the primary fuel system. Simple, and it will cost less than the eventual cost You fellows will encounter filling up with one bad tank of diesel.

In summary... The guys who've experienced the bad tank of diesel and a sludge problem, and paid the price.... We get it, which is why we've all installed polishing systems. Eventually, you'll find out the hard way and purchase a polishing system like us.

[weavis]

Originally Posted by Kenomac

Weavis and Dockhead,

I check my tanks via two clear plastic chamber lids that measure 12 inches across. It's easy to do, only takes a minute. There's isn't any crud in the tanks due to my use of the initial screening filter funnel I use when filling, and the the subsequent polishing. Even if I had a partial blockage (which is so unlikely that it's probably statistically impossible) I can always switch over to the second Racor filter in about..... 1-2 seconds giving me a brand new filter.

Forget about the professional cleaners, just dump any bad fuel like I did two years ago, give the tank a good cleaning, then install a high quality polishing system which runs separate from the primary fuel system. Simple, and it will cost less than the eventual cost You fellows will encounter filling up with one bad tank of diesel.

In summary... The guys who've experienced the bad tank of diesel and a sludge problem, and paid the price.... We get it, which is why we've all installed polishing systems. Eventually, you'll find out the hard way and purchase a polishing system like us.

But Ken. You just admitted to checking your tanks. That was all that was said to do.