Fuel Polishing onboard
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Pack Mule
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We have one that 's a simple set up . It has filter , pump , push pull switch , and wire with alligator clips that I attach to nearby generator start battery . The suction side is plumbed to all 5 tanks . The discharge side is just a long open end hose that reaches to any of the tank deck fills . It's kind of a home boy type rig but it works .
Marty, what filter do you use, and do you some way to extract the water also?
Capt.Bill11
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They all are.
We have Alfa Laval and I recommend it on a boat that you cruise offshore and long distances. Now that's not to say for one moment fuel problems are confined to that use. You can definitely have them coastal cruising in the US but then you are within the towing areas. And if I was in an area without tow assistance, I'd probably get one.
Capt.Bill11
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![image[1]%20(2)[2].jpg](/data/attachments/48/48682-6fa2627278143bccafc021902d9056cc.jpg)
O C Diver
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Mine is a Racor 1000 with a 30 micron filter. I installed it to do both fuel polishing and fuel transfer between tanks. Mine draws from the lowest point in the tank where water and heavy impurities would collect. Typically suck the bottom of both tanks every few days to empty the corner. One of the nice features of using a clear bowl separator is that when you first turn the pump on, you can see if any thing has collected there.
If you buy a boat with a polisher or you add one, it's important to verify you are drawing from the very bottom of the tank. Much less effective if you aren't removing any water in the bottom of the tank.
Ted
If you buy a boat with a polisher or you add one, it's important to verify you are drawing from the very bottom of the tank. Much less effective if you aren't removing any water in the bottom of the tank.
Ted
choppywater
Veteran Member
We are set up with 5 tanks. The one tank is a day tank that will last about 29 hours of cruise.
The 5 tanks are plumbed into a pump that will move fuel from any tank to any tank. It has dual 30 micron filters. Unless there is a reason (long distance travel with questionable fuel) we only run one water separator at a time.
The key is to get clean fuel, keep the tank fills sealed, and use desiccant breathers on the vents.
If i was going to take on questionable fuel i would pump it into one tank and filter it into the other tanks.
You can polish fuel all you want, but it's just a band aid. In a larger tank you will never polish a tank clean and will keep having issues until you get the tanks cleaned and fix the problems.
The 5 tanks are plumbed into a pump that will move fuel from any tank to any tank. It has dual 30 micron filters. Unless there is a reason (long distance travel with questionable fuel) we only run one water separator at a time.
The key is to get clean fuel, keep the tank fills sealed, and use desiccant breathers on the vents.
If i was going to take on questionable fuel i would pump it into one tank and filter it into the other tanks.
You can polish fuel all you want, but it's just a band aid. In a larger tank you will never polish a tank clean and will keep having issues until you get the tanks cleaned and fix the problems.
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sunchaser
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Most fuel polishers are nothing more than an extra stage of filtration. To the OP, suggest you read about fuel filtration on boatdiesel.com.
Nordhavns with their day tank setup seems pretty thorough and once into larger boats the penultimate is an Alfa Laval as BB mentions.
Boating destinations trumps all IMHO. If you can't t good fuel then some sort of additional filtration seems wise. Many get lulled into thinking that a lackluster fuel polisher is more important than buying good fuel, uh uh.
Nordhavns with their day tank setup seems pretty thorough and once into larger boats the penultimate is an Alfa Laval as BB mentions.
Boating destinations trumps all IMHO. If you can't t good fuel then some sort of additional filtration seems wise. Many get lulled into thinking that a lackluster fuel polisher is more important than buying good fuel, uh uh.
They aren't polishers then. They're just additional filters.
From everything I have read this is true, there is more to polishing fuel than just additional filtering.
Walt-here you go-
The difference between Fuel Polishing and Fuel Filtration | Diesel Fuel Cleaning
Until your question, I actually didn't know all that stuff, especially the part about fuel lubricity.
We have an ESI system onboard.
The difference between Fuel Polishing and Fuel Filtration | Diesel Fuel Cleaning
Until your question, I actually didn't know all that stuff, especially the part about fuel lubricity.
We have an ESI system onboard.
Crusty Chief
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There, that looks better. Unless Pairadice relocated from the PNW to NSW
Crusty Chief
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Thank you Sir!
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Conall63
Senior Member
My set up is home built so it's bulky. I, like OC, use it for transfer and polish.
Basically, the manifold on the upper right lets me pull from any of my four tanks, and the manifold on the lower left distributes to any of the four tanks ( there is also a port to pump into an external tank ). Mine is AC powered, and all the fuel goes through a flow meter as this is how I keep track of how much fuel we have.
In case the pump fails or no AC power and have to transfer in an emergency, I have a by pass set up with a manual pump.
Conall
Basically, the manifold on the upper right lets me pull from any of my four tanks, and the manifold on the lower left distributes to any of the four tanks ( there is also a port to pump into an external tank ). Mine is AC powered, and all the fuel goes through a flow meter as this is how I keep track of how much fuel we have.
In case the pump fails or no AC power and have to transfer in an emergency, I have a by pass set up with a manual pump.
Conall
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twistedtree
Guru
Just because a system has an extra filter and a pump doesn't make it an effective polishing system. Some key features that do help are:
- fuel pickup from the very bottom of the tank. This is where water and other guck will settle, and if you system can't pick it up then it's doing no good. Dip tube pickups are typically designed to have exactly the opposite characteristics and intentionally pick up from a point above the guck. Most of the Nordhavn I have seen work this was and as such are advertised as transfer systems, not polishing systems.
- a fuel return location and fuel flow rate that will actually cause some agitation in the tank. This will stir up settled gunk so it can be sucked through the polishing filter. Most builtin polishers do not accomplish this as all since they use the normal top of tank return port. But this capability is really only important to rectify a long accumulation of gunk, and if you have such a situation, a polishing service should have the necessary equipment with return hoses that can be directed to different areas in the tank.
Because of all this, I seriously doubt that most boat polishing systems provide any real benefit that is not also provided by your main filters and the engine constantly circulating fuel. That will remove suspended impurities just as well as a polisher using the same pickup and return ports on the tank.
I think the best defense against bad fuel is to have some sort of fuel segregation policy where possible given the boats tankage. Purchased fuel goes in one place, and fuel to burn goes someplace else, and never the two shall mix - except via transfer through a filter and water separator. You can call it a day tank, but I think there are other ways to accomplish the same thing without a specific day tank. But it's all highly dependent on your boats configuration.
But segregating purchased fuel and burn fuel doesn't absolve you of the need to monitor and keep the purchased fuel tank clean, and so brings us right back where we started. But al least bit keeps the crap away from the engine, which I think is priority one!
- fuel pickup from the very bottom of the tank. This is where water and other guck will settle, and if you system can't pick it up then it's doing no good. Dip tube pickups are typically designed to have exactly the opposite characteristics and intentionally pick up from a point above the guck. Most of the Nordhavn I have seen work this was and as such are advertised as transfer systems, not polishing systems.
- a fuel return location and fuel flow rate that will actually cause some agitation in the tank. This will stir up settled gunk so it can be sucked through the polishing filter. Most builtin polishers do not accomplish this as all since they use the normal top of tank return port. But this capability is really only important to rectify a long accumulation of gunk, and if you have such a situation, a polishing service should have the necessary equipment with return hoses that can be directed to different areas in the tank.
Because of all this, I seriously doubt that most boat polishing systems provide any real benefit that is not also provided by your main filters and the engine constantly circulating fuel. That will remove suspended impurities just as well as a polisher using the same pickup and return ports on the tank.
I think the best defense against bad fuel is to have some sort of fuel segregation policy where possible given the boats tankage. Purchased fuel goes in one place, and fuel to burn goes someplace else, and never the two shall mix - except via transfer through a filter and water separator. You can call it a day tank, but I think there are other ways to accomplish the same thing without a specific day tank. But it's all highly dependent on your boats configuration.
But segregating purchased fuel and burn fuel doesn't absolve you of the need to monitor and keep the purchased fuel tank clean, and so brings us right back where we started. But al least bit keeps the crap away from the engine, which I think is priority one!
sunchaser
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Thank you Peter. Valid points. I'd add to your list chemical treatment via additives, lubricity enhancers and cetane modifiers - seldom if ever done on recreational vessels.
THD posted an article (#20) that states some details suggesting polishing is more than filtration. Thus far in this thread there are descriptions and pictures of some very nice fuel transfer setups that filter the fuel as it is moved from tank to tank.
Lost in the shuffle is the reality of fuel return via on engine filtering that can amount to a very large continuous flow. Excepting Lehmans of course that recirculate little and can run just fine with paper towels as filters.
So here is the question - is a setup of off engine filters, valves, vacuum gauges and in some cases manufacturer decals really polishing or just good marketing?
THD posted an article (#20) that states some details suggesting polishing is more than filtration. Thus far in this thread there are descriptions and pictures of some very nice fuel transfer setups that filter the fuel as it is moved from tank to tank.
Lost in the shuffle is the reality of fuel return via on engine filtering that can amount to a very large continuous flow. Excepting Lehmans of course that recirculate little and can run just fine with paper towels as filters.
So here is the question - is a setup of off engine filters, valves, vacuum gauges and in some cases manufacturer decals really polishing or just good marketing?
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IntervaleII
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twistedtree
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I think it's probably all useful for main filtration and fuel transfer. I can't think of anything in my system that I would remove if doing it again, and I have a few things on my list to add. But calling them polishing systems I think is a stretch unless they minimally pick up from the very bottom of the tanks, which some surely do.
Capt.Bill11
Guru
"Because of all this, I seriously doubt that most boat polishing systems provide any real benefit that is not also provided by your main filters and the engine constantly circulating fuel. That will remove suspended impurities just as well as a polisher using the same pickup and return ports on the tank. "
If you run your auxiliary filter system while underway in rough weather when to fuel may be stirred up you should get some benefit. Especially if you have an engine that returns little fuel to the tank. But other than that I fully agree with your statement.
If you run your auxiliary filter system while underway in rough weather when to fuel may be stirred up you should get some benefit. Especially if you have an engine that returns little fuel to the tank. But other than that I fully agree with your statement.
