Fuel Polishing

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timjet

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Apr 9, 2009
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I need to get the junk out of the bottom of my diesel fuel tanks. The engines rpm decay when the junk clogs the filters.
I can see some flakes of junk in the bottom of the tanks. My question is how do you get this stuff out? Simply sucking the fuel out and through a filter will not get the junk off the bottom. So how is it done. I've tried pro fuel polishers but it didn't get the bottom stuff out. I have no junk suspended in the fuel, it's all on the bottom.
I have considered connecting my racors in series and doing it my self but I still don't know how I would get it off the bottom.
Suggestions??
 
Professional fuel polishing companies have ways of doing this. You might do better with one than trying to do it yourself. The ones I have seen have a lot of equipment that it wouldn't be practical for a boat owner to buy for just one boat.
 
Tim, there is only one way to do this right. Empty the tank and then get in there and clean it. the fuel can be cleaned while it's out. Anything else will leave stuff in the bottom. That means you need to be able to get into the tanks. Ours have a large port added to the side of both tanks so we can get in and clean it thoroughly. Any other means will not get the crud off the bottom and side of the tank. A lot of it collects along the baffles. Chuck
 
As Captain Chuck says, you have to get in there and clean it. A properly designed fuel tank will have one or more access ports to facilitate this. Once access has been gained the crud can be mopped up or sucked up.

Polishing the fuel will get you nice clean fuel but it won't do anything to remove the buildup on the bottom of the tank. This is one reason that a really good tank design will have a sump and a drain at the bottom of the tank--- or like ours will actually feed fuel from the lowest point of the tank as opposed to a pickup tube--- to make it easy to draw off any contaminates, water, etc. before it all settles and sits to congeal into crud.
 
Well I was afraid you guys were going to say a manual cleaning was necessary. In my experience I think you're right. I had fuel polished 2 years ago and it did no good. They used no equipment that I couldn't put together myself.
The problem is I can't really get to the tanks. The tanks are about 5 feet long with a 6" diameter inspection hole in each tank, way to small to do any good as far as cleaning. I'm not sure new holes can be cut, I guess they can but it would be very difficult to do.

Is there a company that does this? Would I look for fuel tank installers, if there is such a company?
 
Greetings,
There is a member on this site who does fuel polishing in FL and I think he may do tank cleaning as well but I'm not sure. Can't remember who but his tag was "Sucking sludge and having a blast" or some such.
 
Old Gas??

Need some advice?? The gas in my port tank, about 35 gal, was purchased at my marina in 2008 and is ethanol free. One dock neighbor said I should drain it and replace with fresh gas, as the gas is old and ruined!! Another neighbor, who owns the pump I was to borrow, said just put in some seafoam and about 5 gallons of high octane gas and it would be fine to use. He pumped 275 gallons of 5 year old gas from another neighbor and has been burning it in his pick up with no problems!!
 
I got an estimate from a company to physically clean my two 150g tanks (that have a 12" access panel) for only $600... That is way less than I imagined and well worth him doing it in four hours AND getting the tanks properly sealed again. Heading down to Beaufort to get him to do it in three weeks.
 
sludge cleaning is NOT fuel polishing...even if you hire a company to do it...it will be an extra charge by every company I've heard or read about.

Make sure you SPECIFY that in the contract because most guys will come out, polish, then charge you hundreds for the polish and say...you DIDN'T say clean the bottom!!!! :eek:
 
I watched a company cleaning tanks and polishing fuel at my marina. They had a couple one hundred gallon tanks, a bunch of filters, a pump and wands, and of course solvents.

They pumped the fuel out of the boat, filtered it and stored it in their tanks. Then, using wands, they pumped solvent under pressure into the boat tanks through any available openings (like the leve sensor opening). The wands allowed them to get into corners and around baffles.

The solvent was removed, filtered, and re-used until the tanks were clean.

Then the solvent was removed and the (now polished) fuel returned to the boat.

While it probably doesn't take an advanced engineering degree to perform this work, it does take a lot of equipment and some training and experience. It didn't seem like a good candidate for DIY.
 
Need some advice?? The gas in my port tank, about 35 gal, was purchased at my marina in 2008 and is ethanol free. One dock neighbor said I should drain it and replace with fresh gas, as the gas is old and ruined!! Another neighbor, who owns the pump I was to borrow, said just put in some seafoam and about 5 gallons of high octane gas and it would be fine to use. He pumped 275 gallons of 5 year old gas from another neighbor and has been burning it in his pick up with no problems!!

I believed that for a while.

I had some old boat gas so I began using it in a new lawnmower. After several weeks, the mower wouldn't start so I took it to the shop for "warranty" repairs. The guy removed the gas cap, stuck his finger in the gas, removed it, smelled it, and proclaimed "bad gas, it's not covered under the warranty". Saving a few dollars by using old gas cost me $70.00.

With all the sensors and such in vehicles these days, I don't think I would be using five year old gas in a newer vehicle. I suppose 10% mixed with fresh gas might not hurt but it would be a real pain to store and manage.
 
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sludge cleaning is NOT fuel polishing...even if you hire a company to do it...it will be an extra charge by every company I've heard or read about.

Make sure you SPECIFY that in the contract because most guys will come out, polish, then charge you hundreds for the polish and say...you DIDN'T say clean the bottom!!!! :eek:

Yes, he DID say he would open the tanks and scrape the crud out of the bottom of my tanks. Please don't presume things like this. I specifically ask what they would do and he laid it out for me very clearly. ;)

Tom-
 
sludge cleaning is NOT fuel polishing...even if you hire a company to do it...it will be an extra charge by every company I've heard or read about.

Make sure you SPECIFY that in the contract because most guys will come out, polish, then charge you hundreds for the polish and say...you DIDN'T say clean the bottom!!!! :eek:

Yes I think you're right, you must specify fuel tank cleaning not just polishing. In my experience the fuel polisher told me to stir up the fuel in the tanks by taking the boat out and doing donuts (running over my own wake several times) just before he got to the dock. Needless to say this was a waste of time and money, it did no good.
 
They pumped the fuel out of the boat, filtered it and stored it in their tanks. Then, using wands, they pumped solvent under pressure into the boat tanks through any available openings (like the leve sensor opening). The wands allowed them to get into corners and around baffles.

The solvent was removed, filtered, and re-used until the tanks were clean.

Then the solvent was removed and the (now polished) fuel returned to the boat.

That's probably far cheaper than opening up the tank and manually removing the crud, if it works.

I'm going to call a couple of local companies and see what they say.
 
This is one reason that a really good tank design will have a sump and a drain at the bottom of the tank--- or like ours will actually feed fuel from the lowest point of the tank as opposed to a pickup tube--- to make it easy to draw off any contaminates, water, etc. before it all settles and sits to congeal into crud.

My boat was not designed to be easy to maintain and certainly the tanks were not designed with sumps to allow cleaning or even large access plates.
My boat was designed to look cool go fast and have way more interior room than similar boats with large engines rooms and sea worthy hulls. Life is full of compromises and this was my choice. Now I just have to figure out a way to live with it.
 
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...he would open the tanks and scrape the crud out of the bottom of my tanks...

I hope you have better access to the inside of your tanks than I do.

I'm in the process of cleaning our tanks as we speak and it is an eye opener. :eek: I will only be able to do a partial cleaning. We have one inspection port located at the front of each tank. Once I opened the access port I found I have 3 baffles inside, 4 chambers. I'll clean the best I can and then close it up. I will later add inspection ports for access to all the chambers. I'll probably use these or an equivalent. http://www.seabuilt.com/ The tanks are 350 gallon each.

I'm sure some of the professional tank cleaners have better tools than I have but in my opinion, to do it right, you need access to all the chambers.


The crud was amazing. I wish the pictures showed more.
 

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Mine is not that bad (there's another on the other tank too). The space next to the motor is bigger than it looks in this picture. I fit in there all the time. Ok, it's not EASY, but there is room to work. :thumb:
 

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The best time to polish/clean the fuel is during a wind/rain storm when the boat is rocking and rolling. I mainly polish/clean the fuel during the 9 months of PNW rain/wind tied to the dock. About 40 to 80 hours. Some Diesel engines polish/clean the fuel when running as they draw more than the use. The DD 671 draw about 60 gal/hour but use about 5 gal/hour.

You could installed double Racor/diesel filters with a vacuum gauge that will let you know if the filter is getting dirty and with double filters easy/quick to switch over to a new filter and then replace the old. the vaccum gauges are one of the first thing I look at when in the engine room, and one of the most used gauges on the boat.

The new ultra low diesel is a good cleaning agent the DD 671 fuel pump seal leaked and pump diesel into the oil. By the time I noticed the oil level was high and the oil was thin it had cleaned the 671 engine spotless, even the valley pan. Luckily I caught it in time and did not damage to the engine, just cleaned it like new.

However, I did open the middle tank. Cut 18” X 18” hole so I could actually clime into the 400 gallon tank. It was winter and I had nothing better to do while it poured down rain. The tank is it good shape with some stuff on the bottom but not that much. Based on the other that tank I have not opened up the other two, but I due polish/turn the fuel, mostly during winter wind/rain storms with the boat rocking, and keep a close eye on the filters. In the spring when the tanks are low, I add additives to absorb water, and dissolves the gunk and polish the heck out of it.

I would recommend to install double filters even if you do not have tank problems, because some day you may take on some bad fuel from the bottom of the tank, and then you get to do it all over again. Because of that I take on fuel one in one tank and transfer to the other 2 tanks, so problems are hopeful contained in one tank.

Oh, If diesel fuel, cutting a hole in a tank and cleaning the tank is not that hard and/or dangerous, if you are bored and want something to due. Hey wife, if you need me, I will be down in the engine room cutting holes in our fuel tanks, if you need me? :eek:
 
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Yes, he DID say he would open the tanks and scrape the crud out of the bottom of my tanks. Please don't presume things like this. I specifically ask what they would do and he laid it out for me very clearly. ;)

Tom-

I'm NOT presuming anything...the company I work for for the last 10 years does fuel polishing, or disposal....

The company reminded ALL of us constantly that polishing is NOT cleaning tanks.

If you asked and he said cleaning was part of HIS proceedure...great...not the industry standard.

I was providing information to the forum...not necessarily just a specific towards you. The generic warning is much more valuable to people thinking about polishing than just one specific instance.

Some people have a clue and some don't... so take what people post as a generic unless they spell you out specifically.
 
^ This looks like an appology to me ... kinda... I thought he was presuming as well :)
 
Gentlemen (and Ladies), somewhat off topic;
a little while ago there was a "lively discussion" regarding optimum fuel filter micron size. I can't find it in the archives or looking back through the threads. Does anyone recall what the title of the thread was? KJ
 
Yes, that's it. Thank you. KJ
 
Same here... I polish at 30 then filter 10 to 2.


Why would you polish with 30 and leave the big stuff for the engine filters?

The Racor used to polish is 2, the Racor to the engine is 10 and the 671 engine filter is 2 or 3. The double Rocors are the 1000, 180 gph, and the fuel is clean so I guess I could go all 3? Never thought about it?
 
Why would you polish with 30 and leave the big stuff for the engine filters?

The Racor used to polish is 2, the Racor to the engine is 10 and the 671 engine filter is 2 or 3. The double Rocors are the 1000, 180 gph, and the fuel is clean so I guess I could go all 3? Never thought about it?
Because there are filters to trap the stuff before it gets to the engine...just not tons of stuff that the 10-30 are taking out in the polishing...instead of the other way around...

Neither is right or wrong...just a different appraoch and the amount of filters used maybe...
 
In the current issue of PassageMaker, Steve D'Antonio has an article dealing with trying to create a fuel polishing system as a DIY project.

One of the points he made is that the return line should be at the bottom of the tank, not the top where a normal excess fuel return is placed. It should also be at the opposite end of the tank from the fuel pickup to encourage fuel movement so you don't just polish the same fuel over and over again.

He makes other points so for anyone considering trying to design a fuel polishing system for a boat should probably read the entire article.
 
If you search the archives using "micron" for the keyword it should unearth all sorts of posts and discussions.

On the advice of our diesel shop as well as friends in the marine diesel and generator manufacturing industry we have run 2 micron filters only for the last 14 years. Primary and secondary. Our (and their) philosophy is to catch everything as far from the engine's injection pump and injectors as possible.

Our boat had new tanks when we bought it, all tanks gravity feed from the lowest point in their bottoms (no pickup tubes in the system), and our fuel supplier has a high turnover of product so the fuel is very clean. So our filters don't have much-- if anything-- to do.

Now if a boat has dirty tanks or if the fuel supply is questionable it might make sense to run a progressive filter setup, say 10 micron closer to the tank and 2 micron closer to the engine. While crud is crud and it will collect in the filter elements no matter what, having a 10/2 setup might at least extend the time a bit before the elements need to be changed since everything's not ending up in the first filter down from the tank.

But I think I'd still rather be catching everything as far from the engine as possible even if it meant changing the element in the first filter in the line more often.
 
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