Fuel polishing - how often?

[Toys_with_time]

After a bad experience with (Greek) diesel fuel last year that cost me $$$$ I have installed a fuel polisher. Intend to run it both summer and when the boat is laid up for winter. System consists of 2 Separ filter / water separators (30 & 10 micron), a small pump and a 12v timer. My fuel tank is 300 litres and the continuously rated pump will move about 90 litres per hour.

The timer can be set for any combination of days and times up to 9 programs. So the question is how often and how long should I run it in summer and ditto for winter?

TwT


Sent from my iPad using Cruisers Sailing Forum

[Muckle Flugga]

Originally Posted by Toys_with_time

After a bad experience with (Greek) diesel fuel last year that cost me $$$$ I have installed a fuel polisher. Intend to run it both summer and when the boat is laid up for winter. System consists of 2 Separ filter / water separators (30 & 10 micron), a small pump and a 12v timer. My fuel tank is 300 litres and the continuously rated pump will move about 90 litres per hour.

The timer can be set for any combination of days and times up to 9 programs. So the question is how often and how long should I run it in summer and ditto for winter?

TwT


Sent from my iPad using Cruisers Sailing Forum

I run my polisher (which also has UV filter as in the third world a lot) whenever the tank is filled with anything. I cycle the tank around twice through the filters. Also run it whenever tank has been left unused for awhile. Same thing. Post crap fuel I take it you have cleaned and serviced your injectors?

[Kenomac]

I run our weekly and for one hour each time we're underway. I just checked the tank last evening via the clear plastic port. Not a spec of anything anywhere in the tank, ant the filters are clean. Looking at nine month old crystal clear diesel.

I don't use the timer to polish during the offseason, it would be a disaster if one of the fuel lines came loose, and it's not safe to leave the boat plugged in due to possible electric short circuit causing a fire.

[DeepFrz]

Though a big proponent of fuel polishing I personally would not run it when the boat is laid up over the winter. Run it for 5 or 6 hrs before layup and again during spring commissioning. Run it longer if you get significant crud in the filter. Add a cetane booster in the spring just before running the polisher.

[AnchorageGuy]

TwT, in order for the cleaning to be effective and worth the effort, you need to run the "filter enhancement system" as often as needed until the filters remain clean. There are a lot of variables for determining how long and how often. Of course the more you run it, the better the fuel will be. Chuck

[Xlantic]

I would think water and crud in the fuel tank settles to the bottom of the tank. If the tank has a sump and the fuel pick-up is at that low point, then it should not take long to pick up all the nasty stuff.

If the tank does not have a sump or the fuel pick-up is higher than the sump, then I don't see how the fuel polishing system is going to be effective with the boat in the slip. In this case I would think the time to run the polisher is when sailing, particularly on a wavy day when the crud in the tank is agitated and lifts off the bottom.

[rhubstuff]

=1 for xlantic. If you just polish fuel in layup or at the dock, you're not getting the crud out of the bottom and corners. The fuel should be agitated, mechanically if necessary, to force foreign material in suspension so the polisher can filter it out of the system. That said, only a small amount of all the fuel that runs through the fuel pump is sent to the injectors; the rest is returned to the tank, having been polished by your regular fuel filters. So what is the point of a separate filtering system, except in places where you actually expect to get bad fuel?

[holmek]

I'm having trouble understanding this whole paranoia. I live on a farm and have diesel tractors. I fill the farm bulk tank ( 2000lt ) once a year. The tractors have 2 fuel filters in line, no sweat - ever. Most boat motors are marinised versions of regular diesel engines, so what is it with the "polishing"?
So long as you have a water trap filter and a regular diesel filter, what is the worry?! There has been talk of the diesel reverting back to tar/crude/bitumen if it is not used within a short time period, - baloney, mine sits in the bulk tank on the farm for the whole year, and then some. Let's get some expert fuel engineer advice here, tempered with the fact that OLD diesel in my farm tank is just fine.

[Xlantic]

Originally Posted by holmek

I'm having trouble understanding this whole paranoia. I live on a farm and have diesel tractors. I fill the farm bulk tank ( 2000lt ) once a year. The tractors have 2 fuel filters in line, no sweat - ever. Most boat motors are marinised versions of regular diesel engines, so what is it with the "polishing"?
So long as you have a water trap filter and a regular diesel filter, what is the worry?! There has been talk of the diesel reverting back to tar/crude/bitumen if it is not used within a short time period, - baloney, mine sits in the bulk tank on the farm for the whole year, and then some. Let's get some expert fuel engineer advice here, tempered with the fact that OLD diesel in my farm tank is just fine.

I think the important difference is that farm tanks don't move and boat do. I believe over the years, decades for many of our boats, crud accumulates in the bottom of the tanks. The source of this crud (asphaltenes from the breakdown of the fuel, "algae" or some biological by-podruct, water or who knows) is better left for another discussion. This stuff can accumulate and sit in the bottom of the tank, undisturbed, because the pick-up point for the fuel is above it.

But, in a boat, when you have enough motion from waves, the crud is disturbed, floats up, and is sucked by the pick-up tube. When this happens the filters are overwhelmed, and changing them doesn't solve the problem because the new one gets clogged by the now disturbed crud in the tank. As you can imagine, this happens at the worst possible time, in a seaway. (Ask me how I know this.)

Thus, many of us, particularly with older boats, are paranoid about this issue. My personal opinion is that polishing will not a guarantee the problem is solved. i believe the definitive solution, at least for an older boat, is day tanks.

[Muckle Flugga]

Originally Posted by holmek

I'm having trouble understanding this whole paranoia. I live on a farm and have diesel tractors. I fill the farm bulk tank ( 2000lt ) once a year. The tractors have 2 fuel filters in line, no sweat - ever. Most boat motors are marinised versions of regular diesel engines, so what is it with the "polishing"?
So long as you have a water trap filter and a regular diesel filter, what is the worry?! There has been talk of the diesel reverting back to tar/crude/bitumen if it is not used within a short time period, - baloney, mine sits in the bulk tank on the farm for the whole year, and then some. Let's get some expert fuel engineer advice here, tempered with the fact that OLD diesel in my farm tank is just fine.

Ummm… are you suggesting that "bad" fuel in dodgy third world locations is a myth? I actually don't really understand your point here. You seem to be trading on the idea that an anecdote of one static example can be expanded to every case in the whole world. Do you suppose the entire industry of fuel polishing manufacturers are just the mechanical equivalent of homeopathy?

I assure you, from lots of direct and very personal experience and plenty of further research… it is not.

[Muckle Flugga]

Originally Posted by rhubstuff

=1 for xlantic. If you just polish fuel in layup or at the dock, you're not getting the crud out of the bottom and corners. The fuel should be agitated, mechanically if necessary, to force foreign material in suspension so the polisher can filter it out of the system. That said, only a small amount of all the fuel that runs through the fuel pump is sent to the injectors; the rest is returned to the tank, having been polished by your regular fuel filters. So what is the point of a separate filtering system, except in places where you actually expect to get bad fuel?

Greece is one of those places. As, it has to be said, are many of the best sailing destinations worldwide.

[Toys_with_time]

Originally Posted by Muckle Flugga

I run my polisher (which also has UV filter as in the third world a lot) whenever the tank is filled with anything. I cycle the tank around twice through the filters. Also run it whenever tank has been left unused for awhile. Same thing. Post crap fuel I take it you have cleaned and serviced your injectors?

Yes serviced injectors, dumped all the fuel (properly), replaced engine filters and pre filters / water traps, cleaned the empty tank and started with a fresh fill.

UV filter? For bugs? Hadn't heard of that.

[Toys_with_time]

Originally Posted by Kenomac

I run our weekly and for one hour each time we're underway. I just checked the tank last evening via the clear plastic port. Not a spec of anything anywhere in the tank, ant the filters are clean. Looking at nine month old crystal clear diesel.

I don't use the timer to polish during the offseason, it would be a disaster if one of the fuel lines came loose, and it's not safe to leave the boat plugged in due to possible electric short circuit causing a fire.

Was going to run it off the solar over winter but good point re fuel lines given the tank runs alongside my bunk.

[Toys_with_time]

Originally Posted by holmek

I'm having trouble understanding this whole paranoia. I live on a farm and have diesel tractors. I fill the farm bulk tank ( 2000lt ) once a year. The tractors have 2 fuel filters in line, no sweat - ever. Most boat motors are marinised versions of regular diesel engines, so what is it with the "polishing"?
So long as you have a water trap filter and a regular diesel filter, what is the worry?! There has been talk of the diesel reverting back to tar/crude/bitumen if it is not used within a short time period, - baloney, mine sits in the bulk tank on the farm for the whole year, and then some. Let's get some expert fuel engineer advice here, tempered with the fact that OLD diesel in my farm tank is just fine.

Paranoia? Your tractors can't die when you have just left port after filling up with fuel (from a Greek mobile mini tanker) and then find yourself with 2 dead engines a few minutes later being blown back onto the breakwater. Maybe the rocks in South Africa are soft but the Greek ones aren't.

[Kenomac]

Just fill your tank before you haul out for the season and give the fuel a polishing. No need to polish during the winter as there can be no condensation and you've already filtered out any crud. Come summertime, give it another good polish, launch and go. This plan works for me, others will argue the condensation point endlessly. I leave the boat with a full tank and refuse to argue the point.