Fuel filtration, lessons learned

[Delfin]

I believe I took on 1,000 gallons of marginal fuel at the commercial dock in Honolulu. By marginal, I mean it appeared to have a whole lot of asphaltene in the 2 - 10 micron range, which started clogging filters at the beginning of the return trip from Hawaii to the PNW. This fuel went into two 'wing tanks' and I didn't start drawing it off until we were about 200 miles north of Kauai. After that, the CAT OEM fuel filter had to be changed, and the replacement began showing clogging after another 300 miles or so. Since in 16 years and over 25,000 miles of cruising I had never had a fuel issue before, this was a new experience for me.

Lesson 1: However clean you think your fuel is, or how good your polishing system, carry a boat load of OEM filters. They're usually in the sub 3 micron range of filtration, and can clog quickly.

Delfin's fuel system is comprised of 7 different tanks - day tank, boiler tank, 2 wing tanks,and forward, bilge and stern tanks, totaling 2,250 gallons. I have redundant Racor 1000's to 'polish' at 30 microns, transfer to day and boiler tanks at 10 microns, and 2 Racor 500 filters before fuel reaches the OEM filter. I believe the contamination was in the 2-10 micron range because the 10 micron Racor 1000 used to transfer fuel did not clog at all, but 2 micron filters in the Racor 500 did, and when I switched to Racor 500 10 micron filters just upstream of the OEM filter, that OEM filter started showing signs of clogging. Since I had only one replacement OEM filter (major screw up - see lesson 1), I was pretty worried I would lose power in the middle of the ocean. To extend the life of the OEM, I changed out the Racor 500 10 micron filter with my remaining 2 micron filter. It ran clean for around 20 hours, then started to clog.

Lesson 2: You can reuse Racor type filters by immersing the filter in diesel and taking a small paint brush to the grooves of the pleats of the filter.

Lesson 3: Since lesson 2 is insane, carry a boat load of primary filters, leaning towards more 2 micron than 10 micron.

Eventually, I couldn't get more than a few hours out of a cleaned 2 micron Racor 500, but as we were within a day of home port, just took it out, and relied on the OEM filter, which went the distance, although showed suction in the deep red, meaning it would have only lasted another couple of days.

Bottom line, in addition to the obvious of not being a moron and carrying an insufficient number of filters, based on my experience you can get fuel that passes the 30 micron clean standard out of the refinery but which is loaded with sub 10 micron particles. So going forward I'll be polishing fuel by passing it through a 10 micron Racor 1000, transfering it to the day tank at 2 microns, then using 2 micron filters in the Racor 500 before the fuel reaches the OEM filter on the motor.


This contradicts most of the advice on filtration I've seen, as most recommend only 10 or 30 micron filters upstream of the OEM filter. That's what I had, and that is what failed in my case.

 

[cardude01]

This is great info. Thanks for sharing.

 

[SteveK]

Have you decided on using less than 10 micron in the primary because of this.
Over the years I have read threads with primary smaller than the oem main on engine as changing location was easier.

 

[Hippocampus]

Excellent post. Ran into bad fuel which impacted on voyage once.

Transit was Chesapeake to windwards. Boat had four tanks which could be filled individually and we could transfer between tanks. Wanted to top off before leaving to have maximum range. Emptied one tank while filling the others with known good fuel. But new fill was bad although station had good rep. So had one bad tank.

Trip was intermittently bumpy. Wanted to know for certain we’d have good fuel at time of landfall. Changing filters while it was sporty was to be avoided. Ran through 12 racors and 4 final filters. Ran good tanks when bumpy. Did changes when calmer after using bad tank. Left enough in one of the good tanks for landfall and reserve. Left 2 racors and one final fuel filter as spares just in case one of the good tanks weren’t as good as we thought.

If doing passage would suggest multiple tanks. If doing passage and topping off would do what fuel transfers required so you’re only filling one tank with new. We continued this practice if using sketchy fuel stations. If you didn’t bring it with you you don’t have it so +1 on having as many filters as you can carry.

Now a strong believer in multiple tanks for voyaging boats. Even believe large wing tanks should be divided into two at time of construction. Being able to isolate a bad tank gives you options. Depending upon passage length you might even be able to not use it or have to deal with it until after landfall.

 

[Delfin]

Have you decided on using less than 10 micron in the primary because of this.
Over the years I have read threads with primary smaller than the oem main on engine as changing location was easier.

. Yes, and for the reason mentioned. Changing the OEM at sea means shutting the engine off, which can get pretty rambunctious depending on sea conditions. My Racor 500s are on a manifold, so I can swap one out while underway. I guess my main lesson is protect the OEM filter at all costs since it has to be screwed in or the engine don't run, nor does it if that filter is clogged.

 

[Eli27]

Extremely interesting. I've got a 120 lehman. The boat had the original water separator that I just removed and installed a dual racor. I believe it's model is 75500.

I need to look into the filters. I never thought about the micron ratings till now. I know I have the 10 microns for the racor and I'm not sure what the engine filters are. I bought them from through American diesel. Figured those would be the best for the best filtration.

I think I was wrong.

 

[O C Diver]

While there are merits to progressive reduction of filter size, there's no reason to not polish with a 2 micron filter, as the engine isn't at risk when fuel polishing.

My other thought would be to replace the Racor 500 with a 1000. While there is an investment cost in the swap, the cartridge cost is minimally more, and the filter surface area is probably increased by a factor of 10. Only reason I have a 500 cartridge on the boat was that I thought it unnecessarily on a 9 KW generator.



Ted

 

[Delfin]

Extremely interesting. I've got a 120 lehman. The boat had the original water separator that I just removed and installed a dual racor. I believe it's model is 75500.

I need to look into the filters. I never thought about the micron ratings till now. I know I have the 10 microns for the racor and I'm not sure what the engine filters are. I bought them from through American diesel. Figured those would be the best for the best filtration.

I think I was wrong.

I think most folks would say that relying on 2 micron pre-filters is overkill, and it probably is for coastal cruising. Worse thing that happens is that you have to change out the OEM filter - no big deal and you can do it at the dock or at anchor and if you don't have one, go to a dealer to get one. Well, it is a big deal if you're a dope like me and only carry a single spare because you've never had a problem before and you're hundreds of miles from land. Then you can find out that even fuel from first world sources in busy harbors may not be as clean as it needs to be.

 

[Delfin]

While there are merits to progressive reduction of filter size, there's no reason to not polish with a 2 micron filter, as the engine isn't at risk when fuel polishing.

My other thought would be to replace the Racor 500 with a 1000. While there is an investment cost in the swap, the cartridge cost is minimally more, and the filter surface area is probably increased by a factor of 10. Only reason I have a 500 cartridge on the boat was that I thought it unnecessarily on a 9 KW generator.

View attachment 141637

Ted

I've thought about that Ted, but I already have a Racor 1000 that I will be using for transferring fuel to the Racor 500s, and can polish with that if need be. It's interesting that even though the size of the 500s is a whole lot less than the 1000s, it is rated for 60 gph vs. 180 gph. Since I only draw 2 - 3 gph, the 500 isn't undersized for the job, especially if I end up polishing at 2 before the fuel even gets to those 500s.

 

[twistedtree]

Wow, that's quite the loop hole you encountered.


I'm thinking the solution is to use a 2 micron transfer filter, rather than a 2 micron primary. I'm thinking that would catch the stuff before it gets to the day tank. And having to pause a transfer to change filters doesn't threaten an engine shutdown, at least not for a while.

 

[O C Diver]

I've thought about that Ted, but I already have a Racor 1000 that I will be using for transferring fuel to the Racor 500s, and can polish with that if need be. It's interesting that even though the size of the 500s is a whole lot less than the 1000s, it is rated for 60 gph vs. 180 gph. Since I only draw 2 - 3 gph, the 500 isn't undersized for the job, especially if I end up polishing at 2 before the fuel even gets to those 500s.

While you only draw 2 - 3 GPH (I assume you mean burn), I'm guessing when factoring in the return fuel, the fuel system has a much higher flow rate through the Racor.

Ted

 

[kapnd]

This is geared more to electronic diesels, but as it says right near the beginning, there’s no such thing as diesel fuel too clean!
https://www.sbmar.com/articles/marine-fuel-filtration-the-seaboard-way/
Is it possible that the gunk could have been hiding in your tanks all along, and never became obvious until you drew the tanks down on the long voyage?
Commercial fuel docks at Honolulu service a wide range of ocean going vessels, they can’t afford to pump bad fuel!
If you’re sure that’s what happened, they need to know about it.

 

[Delfin]

This is geared more to electronic diesels, but as it says right near the beginning, there’s no such thing as diesel fuel too clean!
https://www.sbmar.com/articles/marine-fuel-filtration-the-seaboard-way/
Is it possible that the gunk could have been hiding in your tanks all along, and never became obvious until you drew the tanks down on the long voyage?
Commercial fuel docks at Honolulu service a wide range of ocean going vessels, they can’t afford to pump bad fuel!
If you’re sure that’s what happened, they need to know about it.

On departure, I had a full load of fuel and transited without incident. So, I'm assuming that if any crud existed in the tanks, the outbound trip would have stirred it up enough to show up in filters, but it didn't. In Honolulu I took on 1,000 gallons into the wing tanks and after a couple hundred miles, the problem began. These tanks I had cleaned to the extent they needed cleaning a year ago, and run polishing routines most of the time I am out and about. Hard to imagine an explanation for what I observed other than fuel that was within one spec - 30 micron or less contamination, was within another. I have no idea where the fuel at Hewalo comes from. Oahu has a single refinery, but maybe this came from some bunker on the mainland that had been sitting there for a year or two. No clue.


I'd also note that at Hewalo, the boats being refueled aren't going to notice a significant problem with the fuel I took on that I assume was the culprit. Transiting 2600 miles on that fuel is a different proposition and so I don't hold out blame to them. The dock I took on fuel in Anacortes is within eyesight of the refinery, so it is as pristine as it gets. Maybe I just got used to higher standards, but lesson learned.

 

[Delfin]

While you only draw 2 - 3 GPH (I assume you mean burn), I'm guessing when factoring in the return fuel, the fuel system has a much higher flow rate through the Racor.

Ted

That is true. Probably double that for the qty of fuel passing through the filter. I agree with TT, the transfer to day tank filter should be a 2 micron, and guess what Amazon delivered today? A case of 2 micron Racor 1000s.

 

[Simi 60]

Interesting on ours, have always been told the nta855 can run on vomit

The two on engine filters are 20 micron.
The 1000 fg are 10 micron, so on engine filters never see anything to filter.

Never had a fuel issue
Drain a litre out of the crud sump every few months and tip it back in.
Using the same fuel filters gong on 6 years now, check the racors twice yearly and always spotless

But the tip we were given by working trawler guys if after speedy filter swap in bad situation was flick lever onto "cleaner" filter, take out dirty filter, bang it on prop shaft so crud drops off, reinstall and get ready to do same again.

Messy but fast

Oh, and we do have a box of 10mic 2020 on board plus spares for on engine fuel filters.

 

[O C Diver]

That is true. Probably double that for the qty of fuel passing through the filter. I agree with TT, the transfer to day tank filter should be a 2 micron, and guess what Amazon delivered today? A case of 2 micron Racor 1000s.

While I don't know your specific engine, the cautions I would give you are first many injector pumps are fuel cooled. In essence, the excess fuel from the lift pump is taking heat away from your injector pump. When your engine was starving for fuel, it probably wasn't returning any fuel and cooling the injector pump was greatly diminished. I would strongly encourage you to research what GPH of fuel your lift pump moves. As an example, my 4 cylinder John Deere lifts 34 GPH which equates to 20 GPH at cruise. With a less than 2 GPH fuel burn, there's a lot of fuel cooling the injector pump.

The second advantage to a large primary filter for the engine is that with an extremely low flow (compared to what the filter is designed for) solids heavier than diesel tend to fall to the bowl as opposed to being carried in the flow up to the filter cartridge.

Ted

 

[Hippocampus]

Threads seem to divide into two general groups.

One is mechanical v computer controlled engines. Especially older engines that were more tolerant of particulates. Racors do a decent job getting rid of water independent of micron rating. Only an issue swapping out when it’s really sporty as you’re away from the hot engine and can continue to run the engine during the change. The coastal cruiser is less likely to experience sporty weather. So for the coastal cruiser there’s a different level and set of concerns and some posts reflect that.

The passage making boats have two issues that coastal/near shore boats don’t face. They may need all or nearly all the fuel they carry. One reads about the difference between on boat polishing systems as compared to off boat high volume polishing systems. One reads about the limitations of all polishing systems in actually completely cleaning tanks and fuel. So one does what you can and unlike the coastal boat day tanks and multiple sites and levels of filtration would seem de rigor. Take home is for the voyaging boat that final oem filter should be redundant. When changed on schedule it should be pristine.

The passage making boat may also have less control of where and when it bunkers. Therefore be at higher risk for picking up bad fuel. Also after reaching a new cruising grounds much of it fuel it carries may sit for long periods of time allowing more time for growth and aging. My coastal boat takes 600g. Over the course of a year we take on around 1800g. Given returns are filtered and fuel turns over frequently there’s less opportunity for condensation and growth. In effect it’s polished as we bop around even when the polishing system isn’t used. If the boat isn’t used for awhile we do run the polishing system before taking off. Compare this to a 3000 to 5000 nm range boat. She may use the majority of its fuel while changing cruising grounds but a small fraction between passages.

The OP is a long distance cruiser. His concerns and the problems he faces are different than the coastal cruiser. Read the excellent advice offered in this thread and then wonder how much of it is applicable to me now I’m coastal. Is it worth the labor and bucks to rework my fuel system. So far I think my carrying 12 racors and three oem fuel filters is sufficient. Running my on board polishing system for 12h once a month maybe worthwhile. Taking on fuel from high volume dealers a day after delivery may help. Beyond that don’t think additional reworking is worth the bucks.

 

[tvtfc]

The first thing which popped into my mind was how to not put a lot of junk fuel into the tanks in the first place.

Even at a very early stage of planning, I'm considering fuel issues a lot. This because I hypothesize that given the various sanctions pressures, regulatory changes, alternative fuel blends, 'eco' policies, etc, the trend will be toward more sketchy fuels on the market.

Of course this will be lesser problem in areas where the regulatory apparatus is watching out for things on behalf of the consumers so if one stays close to a home port in a highly developed country, or ventures across boarders mainly to find cheap labor or whatever, they might not need worry so much about it. Or about the contamination issues element of the general problem. For my part, I plan on fuel testing apparatus being part of my standard kit. Also an on-board polishing capability.

 

[KnotYet]

I can't come up with the reasoning that increased scrutiny and higher standards,
not to mention technical advances, will result in 'more sketchy fuels on the market'.
It is a practical application of the 'rising tide raising all the boats'.

 

[tvtfc]

I can't come up with the reasoning that increased scrutiny and higher standards,
not to mention technical advances, will result in 'more sketchy fuels on the market'.
It is a practical application of the 'rising tide raising all the boats'.

Has to do with how markets work.

The trend in marine fuels seems to be toward LNG, it being so green and all that. And when people find out there is lethal carbon in LNG (by watching Degrass-Tyson or something), ammonia. Those should be a fun conversions for the pleasure-boating crowd.

Fortunately there will be wide-spread public support for making sure that people who can afford to blow large chunks of $1M on a get-away yacht will be able to continue 'killing the earth' as usual and be given special privileges. Hell, they might even be given free extra-fine virgin diesel so that they don't plug their racors.

---
"Economics don't care what you believe." - tvtfc

 

[KnotYet]

Too much confusion in the above for reasonable comment. Questions, maybe:

1) Do you know of production trawlers (this site's focus) running on LNG (methane)?

2) Ammonia as a motor fuel? Please enlighten.

 

[psneeld]

As far as amonia based fuel, seems the large shipping industry has already converted or built a few large ships that run on some sort of ammonia based system... read a bit about it on GCaptain.

Seems like big shipping is experimenting with 10 or so different fuel systems, but nothing atvour level yet.

https://gcaptain.com/tag/ammonia-fuel/

 

[Jeff F]

Ammonia as a motor fuel? Please enlighten.

Ammonia has attracted interest because it can be created from green sources rather than fossil fuels. Don't think we'll see it on rec boats any time soon.

 

[Snapdragon III]

It might not be practical due to the time it would take to fill up a large boat with 1000+ gallons, but I like the idea of all fuel taken on going into a couple hundred gallon bladder on deck, then polished from there into the actual fuel tanks. The bladder could be rolled up and stored when done and would not take up much room. It would take some setting up to make it easy and practical. Would be much easier if you already had a polishing system you could tap into.

I took on 1500 gal in Hawaii when I brought my boat home, fortunately we didn't have any problems with it. It was a pain in the ass pumping that much fuel though. It took hours. The station was set up so you could only put something like $300 on your credit card at a time so we had run the card a ton of times.

 

[sunchaser]

Ammonia has attracted interest because it can be created from green sources rather than fossil fuels. Don't think we'll see it on rec boats any time soon.

The use of ammonia as a fuel is well beyond the dreaming stage. Ammonia’s energy density is high,
much higher than hydrogens for example. I’ve several friends in the fossil fuel business who cite its future near term potential, particularly in the shipping industry.

A bit of internet sleuthing yields a treasure trove of information for near term uses including the use of wind farms to produce ammonia and spread it onto crops.

 

[tvtfc]

Ammonia has attracted interest because it can be created from green sources rather than fossil fuels. Don't think we'll see it on rec boats any time soon.

Diesel is among the easiest fuel to make from 'green sources'. It can be done in primitive settings with low technology, and it retains most of the positive attributes of it's fossil fuel counterpart.

By the same token, the most profitable way to make ammonia fuels is to use fossil fuels, so that's what would probably happen. If nuclear energy expands massively (esp, via fusion) then things could change massively because with nearly limitless energy one can synthesize nearly limitless fuels.

Ammonia gets mind-share (within what I would refer to as the climate cult) because stociatrically (sp) it contains no carbon. That's a good illustration of about how far your average person thinks.

If you can introduce a technology which is technically difficult to deal with, you can cut out the small fish from amongst the competition. You can also obtain intellectual property rights much deeper into the industrial chain. That looks to me like the driving force behind a lot of this stuff. People do seem to be waking up the the 'green' scamary (as I call it) in accelerating numbers lately, but massive industries are betting a huge amount of money on it's success, and I'm not going to bet against them.

---
Relatedly, I'm seeing more and more of these lately:

https://www.salon.com/2023/08/22/ho...ately-driving-the-climate--while-blaming-you/

These considerations are also shaping my plans in a notable way.

 

[tvtfc]

The use of ammonia as a fuel is well beyond the dreaming stage. Ammonia’s energy density is high,
much higher than hydrogens for example. I’ve several friends in the fossil fuel business who cite its future near term potential, particularly in the shipping industry.

A bit of internet sleuthing yields a treasure trove of information for near term uses including the use of wind farms to produce ammonia and spread it onto crops.

I would suggest that 'high' probably deserves a bit more context. Here's a chart I dug up:

https://marine-service-noord.com/en...s-and-technologies/volumetric-energy-density/

There are many other such ones that do not include ammonia. It's also worth paying attention to the pressures and temperatures associated with some of these figures. Not to mention toxicities, corrosive characteristics, and what-not.

I suspect that there is no real goal to actually used these technologies in a significant way. Rather, just to get some proof-of-concept prototypes on-line so as to kick-start legislation can be used to start to shut out certain classes of competition.

 

[tvtfc]

It might not be practical due to the time it would take to fill up a large boat with 1000+ gallons, but I like the idea of all fuel taken on going into a couple hundred gallon bladder on deck, then polished from there into the actual fuel tanks. The bladder could be rolled up and stored when done and would not take up much room. It would take some setting up to make it easy and practical. Would be much easier if you already had a polishing system you could tap into.

I took on 1500 gal in Hawaii when I brought my boat home, fortunately we didn't have any problems with it. It was a pain in the ass pumping that much fuel though. It took hours. The station was set up so you could only put something like $300 on your credit card at a time so we had run the card a ton of times.

Interesting thought.

I think I've read that on larger ships, tanks are used for both ballast water and fuel simultaneously with no separation.

It would seem to me that smaller vessels there would be a lot more agitation, and less capable scrubbing equipment.

Actual question incoming: Has anyone run across situations where smaller vessels double-up on tanks (water and fuel both) by use of a bladder arrangement of some sort? Seems like such a thing would allow one to take on questionable fuel loads and scrub it at a more leisurely rate.

Similar needs/niceties might apply to water from different sources.

 

[twistedtree]

It might not be practical due to the time it would take to fill up a large boat with 1000+ gallons, but I like the idea of all fuel taken on going into a couple hundred gallon bladder on deck, then polished from there into the actual fuel tanks. The bladder could be rolled up and stored when done and would not take up much room. It would take some setting up to make it easy and practical. Would be much easier if you already had a polishing system you could tap into.

Isn't this essentially the same as using a day tank? You bunker purchased fuel in your main tanks vs temporary on-deck bladders. And you then polish it about 100 gallons at a time wile transferring it to the day tank.

 

[mvweebles]

Bladder and deck tanks are sometimes used to extend range for a delivery. They are a PITA. There are also concerns about trim given they are often placed in an open cockpit or Sundeck since few folks want them on their cabin sole. Transferring fuel in open water can be a challenge and is messy - most boats have deck-fills. Fuel bladders are pretty heavy and robust. Rolling up and stowing isn't as convenient as it sounds. Possible, but barely practical as a range extender. A year or so ago, someone asked about getting a Hatt 60-ish across the Atlantic as they were moving. That's a rare example where a bladder or barrels might make sense.

In my opinion, bladders and barrels are a good example of stuff that looks good on paper and should go no further.

Peter