Fuel polishing system on Nordic Tugs

Hi,
I am getting close to deciding that a Nordic Tug 37 to 42 may be right for me. Budget-wise I am probably looking for a 15+ year old boat. My last boat had twin diesels and so I am experiencing the no-doubt common concerns about keeping that one engine running. So I've been researching fuel polishers.

I've seen some Nordic Tugs on ad that have fuel polishers so others have crossed this bridge before. I'd appreciate any and all thoughts on:

1) what system did you choose and why?

2) are you happy with it?

3) how complex was the installation?

4) what did it cost you?

5) would you install a fuel polishing system on your next boat and would you use the same system?

Thanks. Sorry I guess I ask a lot of questions. I was always that kid in class that asked all the questions. I can't help it.

Pete

Pdxstriper said:

Hi,
I am getting close to deciding that a Nordic Tug 37 to 42 may be right for me. Budget-wise I am probably looking for a 15+ year old boat. My last boat had twin diesels and so I am experiencing the no-doubt common concerns about keeping that one engine running. So I've been researching fuel polishers.

I've seen some Nordic Tugs on ad that have fuel polishers so others have crossed this bridge before. I'd appreciate any and all thoughts on:

1) what system did you choose and why?

2) are you happy with it?

3) how complex was the installation?

4) what did it cost you?

5) would you install a fuel polishing system on your next boat and would you use the same system?

Thanks. Sorry I guess I ask a lot of questions. I was always that kid in class that asked all the questions. I can't help it.

Pete

Click to expand...

You have been drinking the kool aid from guys like Parlatore. Fuel Polishing was necessary in the era before Ultra Low Sulpher fuel. Now, EPA regs require the refineries to give us clean fuel. Unless you are buying a boat that has not been run since the previous owner's wife left him, a few years ago, yours will not need polishing. Even if it is stale and full of water and microbes, there are better ways of getting rid of the critters, like BIOBOR.

Pdxstriper said:

Hi,
I am getting close to deciding that a Nordic Tug 37 to 42 may be right for me. Budget-wise I am probably looking for a 15+ year old boat. My last boat had twin diesels and so I am experiencing the no-doubt common concerns about keeping that one engine running. So I've been researching fuel polishers.

I've seen some Nordic Tugs on ad that have fuel polishers so others have crossed this bridge before. I'd appreciate any and all thoughts on:

1) what system did you choose and why?

2) are you happy with it?

3) how complex was the installation?

4) what did it cost you?

5) would you install a fuel polishing system on your next boat and would you use the same system?

Thanks. Sorry I guess I ask a lot of questions. I was always that kid in class that asked all the questions. I can't help it.

Pete

Click to expand...

As mentioned by a previous poster, if the tanks are clean and you only get clean fuel, fuel polishing may not be necessary. If buying a 15 year old boat, guaranteeing clean tanks is a little tougher. If the boat has only one tank, I might consider adding a Racor 1000 as the first filter (if it doesn't have one) as it's size will handle a lot of crud. With 2 tanks, a polishing / transfer system is very nice to have for trimming the boat with fuel weight.

BTW, if you use additives like BIOBOR, when the stuff dies, it still can end up in your filter in large quantities.

Ted

Pete

For marine fuel filtration tips and expertise visit the SBar Marine website and read Tony's articles. Pretty much the gold standard until one gets into centrifuges like Alfa Laval.

I'll as mentioned by Ted and Keith - today's diesel is pretty clean when purchased from reputable sources.

Hi,

The Nordic tug fuel line starts at the bottom of the tank, so water and dirt are removed from the tank to the Racor filter. I don't see why polishing would add value to the NT boat because they don't have extra storage tanks like some trawlers. This is just my opinion and experience with NT37.

NBs

I had a 2000 Nordic Tug 32 and now have a 2008 NT 37. A few years ago, I had a company in Bellingham put an inspection port in the 32's tank and clean it. It was surprisingly clean. The filters on my 37 remain very clean so I'm not too concerned about gunk from the tanks. However, as previously posted, there is a cross-over line between the tanks on the 37 and it would be easy to install a polisher there.



The NT owners' group has our annual rendezvous in Sidney this June. Whether you own by then or not, you might want to attend just to learn more about the boats. Check out the details at www.panntoa.org.

What engine does it have?

My Nordic Tug's Cummins 6BTA diesel uses diesel fuel to cool injectors and fuel pump. The amount of diesel returned to the tank while under power is significant. You can hear the fuel pouring back into the fuel tank at a fairly high volume. I've always thought that a simple fuel polishing system would just require some filtering system inserted in the return fuel line. This is in addition to the primary (Racor) and on-engine secondary filters. With annual filter changes, enough hours to run through 350 gallons of fuel per season, I'm turning over enough fuel to negate polishing. If your selected boat has a good maintenance record (filter changes), and burns through a reasonable amount of clean fuel per season (purchased from reputable sources), fuel polishing isn't necessary.

Why put the filter in the return line? Why not in the suction line before the dirt gets to the injectors?

You are right that the Cummins (and most modern diesels) pump a lot of spill fuel past the injectors, usually 2 or 3x what they actually use. If your filtration system is good, the engine filters are polishing the fuel on a continuous basis.

If I bought a 15 year old boat I'd be temped to open the tank cleaning ports and have a look. If it was clean, I'd shut them up again and go boating (you could even insist on this as part of the pre-purchase survey). If it was dirty, I'd have it cleaned, then go boating.

Just run the boat with a new set of filters. After 200-300 gal. Remove the filters and open them up. Visually inspect them. If reasonably clean then don’t do anything. New fuel will help polish old fuel while running. We just don’t have diesel fuel problems like the old days. If you take a whiff of fresh diesel it almost has no smell any more. 30 years ago you couldn’t get it off you hands

I guess nobody is gonna answer my questions...

Maybe because people are not doing that much in fuel polishing systems now. I have a 33 years old boat and don’t have a polishing system. I don’t have any indications of dirty fuel. My Racor filters last a very long time, probably much longer than I should let them go...

Pdxstriper said:

I guess nobody is gonna answer my questions...

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There have been 3 other NT owners who gave you answers before this post! That is, most NT owners do not see the need to install a fuel polishing system. If you are insistent that you would want one, then I guess you will have to hope that the rare NT owner that has installed one, takes the time to provide details.
My personal opinion, based on experience with the NT 37, talking to many, many other NT owners, feedback from Tony Athens, (the Cummins guru), and the consensus here, it that a polishing system is not necessary and would be an "extravagance". My Cummins 6BTA engine puts way, way more fuel through the filters than the engine consumes, and the cleaned fuel is returned to the tanks. Fuel is returned to the top of the tank and withdrawn from the bottom. In this way, the whole tank is "cleaned or polished" every time we run the boat for a few hours.
I hope this info meets your needs, because I don't own a polishing system to tell you about.
On the NT 37, there is the previously mentioned cross over line between the 2 tanks. One tank feeds the main, and the other the generator. You could install a "polishing system" in that line, and I have seen one NT 37 that did this. You could also just install a "transfer" pump plumbed into this line to enable ballasting the boat athwartships using fuel. As they come from the factory, this line causes the tanks to "seek their own level" when the valves are open.

Pdxstriper said:

I guess nobody is gonna answer my questions...

Click to expand...

Do you have one tank or two? If you have only one, I gave you the simple solution for fuel polishing while the engine is running. If you have two tanks, building a system will be somewhat dependent on your manifolding. You can build a very respectable system with a Racor 1000 and a 12 VDC diesel fuel pump with a 2 GPM flow rate. Whether you want to incorporate a spring wound timer or just control it from the breaker panel is personal preference. I would guess $700 to $1,000 would get the job done, not counting what you have to do to the manifolding. Here's mine:



Ted

Pdxstriper said:

I guess nobody is gonna answer my questions...

Click to expand...

OK, check in with Tony Athens website and ask same question of a very smart filtration and Cummins diesel guy. You could easily install his 2 stage filter and valves setup for general cruising or use at the dock. All it takes is $ and time for this added complexity.

Well, now you have heard why and why not to have a fuel polisher, about par for the course here on the forum. I am not saying anybody is wrong either.

When I carted 640 gallons of diesel around in four bottom feed tanks with twin 120-HP Lehmans which used little fuel and returned far less, I installed a fuel polishing system after pulling a nasty looking sample up through the fill port with a hand pump. Yes, from bottom feed tanks. The boat was at that time 26 years old. For the next fourteen years I religiously shifter tanks monthly for a thorough polish and replaced the Gulf Coast Junior filter element (toilet paper) when the vacuum gauge needle started to climb.

Adding the polishing system was a simple DIY and cost only the price of the pump, filter body, hose and fittings. Anybody can do it.

Fast forward to my current boat with a single diesel engine which returns 11 GPH at my cruise speed of 16 miles an hour into the two 80-gallon tanks, both tanks are bottom feed from the aft end which ensures everything in the tanks gets sucked out into the Racor filters where I use 2-micron elements. I see little reason to install a polisher here.

Maybe your proposed boat with fit into the category of my current boat, but even if it does, and somebody has taken the time and effort to install a polishing system, I would use it. However, I would not expect any added value would accrue to it because it has one; although the boat would probably have better overall care than one without such a system because the owner obviously was a bit anal.

jleonard said:

What engine does it have?

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I’ll ask one more time
What engine does it have?
Then I can answer your question.

jleonard said:

I’ll ask one more time
What engine does it have?
Then I can answer your question.

Click to expand...

I haven’t decided on a boat yet. Based on my stated choices (NT either 37 or 42) and my budget, I’m prolly looking at early 2000s and they typically have a pre-QSB 330 Cummins.

Nordic Tug 42 Fuel Polisher

Our 2008 came with an ESI fuel polisher from the factory. We have never had bad fuel so we have not used the system. As others have said, the newer diesels return a lot of fuel to the tanks. I changed our Racor 900 10 micron filter last spring, we ran about 230 hrs when I changed the filter. The filter media was dark with no buildup. The differential pressure gauge for the filter barely registered at higher throttle. We keep our deck fill o rings replaced bi-annually and keep the 2 300 gallon tanks full. For our cruising, We do not need the fuel polisher. Last summer we ran from Portland, OR. up to the Broughton's in BC and back. Our tanks definitely got "mixed" a few times on the trip.

Picture of our install:

Pdxstriper said:

I guess nobody is gonna answer my questions...

Click to expand...

I thought I had contributed but, it appears I did not.
Here are MY answers;
Boat, AT34 2008, 2X00gal fuel tanks, engine Cummins QSB 5.9, fuel draws from the bottoms of the tanks.
Fuel polishing system installed, 12 vt Reverso FPS 80 (proprietor filter 50,30,10 microns) Programable weekly schedule or manual 5 hours 'run'
Price at Defender $1750+
After initial install, I used 4X5 hour runs with 30 micron filter. Replaced 30micro with 10micron
Reason for install, after hurricane Irma, I got a shot of water I think through the deck fill, showed up in main Racors. Replaced deck fittings' o'rings.
Results so far; no water in the Reverso 30micron but some unidentified black trash.
Replaced 30micron filter with 10micron filter for 'the long run'. So far, no additional black trash nor water.

What I dont like about it, proprietary filters. They are readily available from various mail order sources.... but, I keep 3X30micron filters on-hand.

And the Reverso URL is.....

Fuel Polishing System - 80 GPH - Separ - Marine

I hope that answers all your question.

OldDan1943 said:

What I dont like about it, proprietary filters. They are readily available from various mail order sources.... but, I keep 3X30micron filters on-hand.

And the Reverso URL is.....

Fuel Polishing System - 80 GPH - Separ - Marine

I hope that answers all your question.

Click to expand...

It was good of you to provide a detailed answer including what you don't like about it. What I don't like about it is the price which boarders on usury.

firehoser75 said:

There have been 3 other NT owners who gave you answers before this post! That is, most NT owners do not see the need to install a fuel polishing system. If you are insistent that you would want one, then I guess you will have to hope that the rare NT owner that has installed one, takes the time to provide details.
My personal opinion, based on experience with the NT 37, talking to many, many other NT owners, feedback from Tony Athens, (the Cummins guru), and the consensus here, it that a polishing system is not necessary and would be an "extravagance". My Cummins 6BTA engine puts way, way more fuel through the filters than the engine consumes, and the cleaned fuel is returned to the tanks. Fuel is returned to the top of the tank and withdrawn from the bottom. In this way, the whole tank is "cleaned or polished" every time we run the boat for a few hours.
I hope this info meets your needs, because I don't own a polishing system to tell you about.
On the NT 37, there is the previously mentioned cross over line between the 2 tanks. One tank feeds the main, and the other the generator. You could install a "polishing system" in that line, and I have seen one NT 37 that did this. You could also just install a "transfer" pump plumbed into this line to enable ballasting the boat athwartships using fuel. As they come from the factory, this line causes the tanks to "seek their own level" when the valves are open.

Click to expand...

Yes,

I just looked at my cummins data, the fuel pump rotates 50 gal / hour in the port side tank and polishes the fuel each time the engine is running. Also, the fuel from the starboard tank is constantly flowing with the amount of engine power consumed, and if you use a generator or heater, these will polish this tank and the fuel will be clean when it flows into the port side tank. As far as I know, all NT boats have a double Racor pre-filter, and if the filter starts to clog up problems, you can switch to another filter or run through both units.

NBs

rgano said:

It was good of you to provide a detailed answer including what you don't like about it. What I don't like about it is the price which boarders on usury.

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rgano, the 'advantages' of buying the Revero system, be it minor: timer, weekly scheduler, come mounted on starboard. Basically, a very 'clean' installation. I have no regrets.
I created a fuel polishing system for my N46 using a standard Racor filter, vacuum gauge, fuel pump, valves, manual electric switch and mounting it. I guess you could mount this on starboard to mount on a convenient ER bulkhead. Price: "cant remember".
If you can picture the N46 fuel manifold and then add more valves to that can of worms, you will see another advantage of buying and installing a Reverso system. I hated the N46 fuel manifold. Of course this fuel manifold was in a cramped ER which made it worse. LOL One of my greatest accomplishments in life has to be drawing out and understand the N46 fuel manifold. I dont miss it.

O C Diver said:

As mentioned by a previous poster, if the tanks are clean and you only get clean fuel, fuel polishing may not be necessary. If buying a 15 year old boat, guaranteeing clean tanks is a little tougher. If the boat has only one tank, I might consider adding a Racor 1000 as the first filter (if it doesn't have one) as it's size will handle a lot of crud. With 2 tanks, a polishing / transfer system is very nice to have for trimming the boat with fuel weight.

BTW, if you use additives like BIOBOR, when the stuff dies, it still can end up in your filter in large quantities.

Ted

Click to expand...

No shortage of opinions on the need for polishing just like anchors and fuel additives. I do not see much value in fuel polishing. Other do, or others just sleep better knowing their fuel has been polished. As another poster observed, fuel is today dispensed much cleaner than in years past. Sure, one can occasionally, very occasionally, rarely, in fact, get a load of dirty fuel. If one does, changes filters as needed and move on.

As most of us are, I was very curious as to what lies in the bottom of my tanks. Is there water, lots of crud? I realized not long ago that I have a drain valve at the bottom of the tanks, hidden, but there. Just an hour ago I drained some fuel from the bottom of one of my tanks. There was not a drop of water and a minimal amount of crud, this from 36-year-old tanks. Whatever crud is there and which is picked up by the supply tube will easily get filtered out by the primary filters.

When we bought this boat (Lehman 120s) six years ago, before leaving Palm Coast on the 950-mile trip north to the Annapolis area, I had the existing fuel polished dockside with no water and no discernible crud through a 2-micron filter. Of course, the boat had seen very little use in the previous three years so there could have been plenty of junk sitting on the bottom of the tanks. Going through St. Andrews Sound with the wind from north we pitched and rolled violently for at least 45 minutes. Whatever crud there might have been at the bottom was certainly stirred up. Yet, we did not have to change filters on the trip home. The filters were changed three years later at 250 hours even though they appeared quite clean. A filter change was next required after 460 hours while doing the Great Loop. Those filters could have easily gone to 500 hours.

Anyway, I will not be spending precious boat bucks on a fuel polishing system. Just one guy's experience and risk/reward reasoning.

Pdxstriper said:

I haven’t decided on a boat yet. Based on my stated choices (NT either 37 or 42) and my budget, I’m prolly looking at early 2000s and they typically have a pre-QSB 330 Cummins.

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That engine cycles 45 gallons per hour thru the system. No way you’ll need a fuel polishing system. The engine itself will do that.
I repowered an old main ship with that same engine. My fuel went from yucky brown to pristine cherry red in 3 day trips.

Why I ask...

Thanks for all the input. Some background on why I asked in the first place:
I bought a 53' Navigator with twin 370 HP Volvo TAMD6 brand new and ran it for 14 years in the beautiful Pacific Northwest. Based in Portland with annual trips north (Gulf Island, Desolation, Broughtons, etc). I had the boat serviced annually and kept everything up to snuff including Biobor. I had 2 incidents.

1) About 8 years in, Cruising from Anacortes to Sidney to meet friends, one tach starts bouncing from 1800 rpm to 1200 rpm, then bounces back. Weird. Obviously a filter. Cruised into port, changed filters, end of story.

2) A couple of years later, running rough and lots of dark in the Racor bowl, I pulled a filter and it was black and cruddy. Like those pictures of what a really bad filter looks like. What happened? I don't exactly know. Did I get a bad batch of fuel? Forgot to Biobor? Boat maybe sat a bit more than usual?

So there you go. Very well maintained boat, I was never in danger but I always had a second engine. I chalk it up to 'random **** happens'. These experiences drove me to research fuel polishing for a single engine boat.

Again, thanks for all the responses.
Pete

FWIW,

In April 2016 we bought a 2002 NT37, 330 hp Cummins 6BTA 5.9 M3. Two fuel tanks, 160 gallons each, with cross-over connection open.

It had not been run all that much - only 1485 hours on the engine, about 100 hours/year. After three weeks of tinkering and setup, took off from Anacortes toward SE Alaska. Rounding Cape Caution on rollers up to 8 feet or so, the fuel got sloshed around a good bit, and toward the end of that day we detected the engine struggling somewhat to maintain RPM.

In the Racor fuel filter bowl, there was a noticeable amount of black gunk. Switched to the other filter, and RPM problem disappeared. Replaced the partially clogged filter, and all was well for another 350 engine hours, when black gunk became noticeable again. Changed filters one more time, and the engine ran perfectly with no accumulated gunk for the next ~2500 hours.

Starting with an initial clearing out of a couple of Racors worth of gunk, we've run some 800 hours each summer for four summers, with no apparent need for a fuel polishing system.

In our previous diesel boat, we did some 6500 hours over 18 years, and the fuel filters never clogged once.

In 1,500+ fuelings with my charter boat, I had one bad load of fuel which managed to reduce the RPM to <1,000 by plugging a Racor 1000. So, bad fuel is rare, but it does happen.

When setting up my trawler fuel system which has 2 tanks, I decided to add fuel to port, and transfer it to starboard as needed to trim the boat. The engine and generator draw from the starboard tank. By passing it through the Racor 1000, I am polishing it to eliminate bad fuel from reaching the day tank. As most of the plumbing and pump already existed, the investment to add the Racor 1000 was around $400. While I may never need to polish the tanks, having the ability to, and filtering all fuel before it reaches the day tank, was worth $400.

Before





After




Ted

Not all NTs have Cummins; there was a stretch where Volvos were installed. Not sure when, but somewhere in the 2000's I believe. And our NT42 has a Lugger/Komatsu.

Thank you. Your response below begs another question. (Note: Is there a limit to dumb questions on this forum?). I came from twin diesels and twin tanks; each tank fed an engine. The crossover was a simple pipe with shutoffs at each tank. In 14 years I never opened them. Simple!

Reading below, it sounds like port tank feeds the main. Got it. The starboard tank feeds the gen and heater, and then the return fuel is fed over to the port tank. That sounds odd. It seems like moving fuel fed from the starboard tank over to port tank tank introduces a risk of overflowing the port tank, I must be missing something. Can someone add some words to help me understand this?

Also how do the tanks get balanced out?

Thanks,
Pete

North Baltic sea said:

Yes,

I just looked at my cummins data, the fuel pump rotates 50 gal / hour in the port side tank and polishes the fuel each time the engine is running. Also, the fuel from the starboard tank is constantly flowing with the amount of engine power consumed, and if you use a generator or heater, these will polish this tank and the fuel will be clean when it flows into the port side tank. As far as I know, all NT boats have a double Racor pre-filter, and if the filter starts to clog up problems, you can switch to another filter or run through both units.

NBs

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