Diesel Fuel Polishing

[downunder]

Read about Jedi’s system from Post 21. Lots of good info pertinent to the questions you are asking .
You find his description here: A new fuel system for Jedi (English) - s/v Jedi
“pump has a mechanical timer switch. The other pump is labelled "boost/prime" and connected to the supply manifold. It has a regular on/off switch which can be seen on the first photo... just hanging by it's leads as the switches aren't mounted yet. These pumps have a maximum rate of 43 gallons per hour and limit the pressure to 7 psi.
The filters are all Racor 500 series; the pumps are Walbro 6802; the manifolds and valves are manufactured using 1/4" bronze and brass parts and the fuel-lines are 3/8" flexible hose type A1. “
Cheers

[steveebryant]

And thanks to all of you for contributing to my knowledge base and now to my increased optimism!

[steveebryant]

. . . . . what is the function of the "permalink" number found in the upper right corner of each of our messages?

[goboatingnow]

Any impeller pump will do as long as the lift isn't too great ( 1-2 feet) it will then self prime. It must have nitrile impellers and seals. I've used a jabsco one for years.

Dave

[mbianka]

Originally Posted by rebel heart

My $0.02:

If your tank is clean, you don't need to polish fuel. If the tank is dirty, polishing the fuel won't make a difference.

Got to agree with Rebel Heart here. I converted to electric propulsion so I don't have any more fuel worries. When I got around to looking inside the fuel tank I was amazed to see what was coating the tank. Here is exhibit A:
THE BIANKA LOG BLOG: IN THE TANK: Part One, Scene of the grime!
IMO cleaning the fuel without cleaning the tank is wasting money and asking for trouble further down the road at least from what I could see after looking into my boat's former fuel tank.

[TeddyDiver]

Originally Posted by mbianka

Got to agree with Rebel Heart here.

The point in fuel polishing is to prevent having dirty tank and fuel ever..
But if you two run allways with 1st class clean fuel filling up regularly without any fear of getting inpurities any other way so be it..

[Lowcountry]

I had tank contamination issues when I first bought my boat in 2008. Two years ago, I built a portable fuel polishing system that is essentially exactly like the one you describe in your original post. I bought a 12V diesel lift pump from either Northern Tool or Harbor Freight (I forget which). This pump was specifically designed for pumping diesel. It came with about 12' of hose and a basic gas-station-style nozzle, as well as alligator clips to connect the pump to the house bank. I also bought a 500-series Racor filter. I then went to Lowe's and bought a 1"x10"x48" board to mount the pump and the Racor on. When not in use, I remove the pump and Racor from the board, and everything goes into the lazarette for storage.
On the intake side of the pump, I put a small metal wand that allows me to fish around inside of the tank (through the hole that the fuel gauge rests in) and around the baffles. The diesel then goes through the pump first (per manufacturer's reccommendation), then through the Racor, and finally through the nozzle and back into the tank via the deck-fill (I route the hose out through a port hole to the deck-fill). The pump moves the diesel at a rate of 60GPH, and I have a 48 gallon tank. I usually polish the fuel when I have less than half a tank, and can cycle it through several times over the course of an hour. I polish the fuel this way 2-3 times a year. I have been very pleased with the results, and have not plugged a filter at sea since I began polishing my fuel (I had plugged dozens of filters before this when at sea).
As for the poster who claimed that this is a waste of time, I would have to respectfully disagree. While you can never fully remove all of the contaminant, you can certainly keep the level way, way down, and you can greatly reduce the chances of plugging your fuel filters when offshore.
All told, I spent about $500 building this system. Considering that many professionals charge $400 for one polishing, the system pays for itself after two uses. Also, the fact that its portable allows me to use it on other boats when needed, and as such provides a source of possible (small) income while cruising.
I have pictures of my set-up somewhere, and will post them here if I can find them.

[s/v Jedi]

Originally Posted by goboatingnow

Any impeller pump will do as long as the lift isn't too great ( 1-2 feet) it will then self prime. It must have nitrile impellers and seals. I've used a jabsco one for years.

Dave

There are two important things to consider for the fuel pump:

1. Pump capacity is compatible with the filter flow rate specification.
2. Pump maximum pressure is less than max allowed for filters and engine in case of bleed/boost pump (or it would pop gaskets out of filter or damage high ressure pump etc.) For Racor's, max. Pressure is 15 psi. The Walbro's I used limit at 7 psi and do half the max. flow rate of a Racor 500.

ciao!
Nick.

[delmarrey]

Originally Posted by steveebryant

. . . . . what is the function of the "permalink" number found in the upper right corner of each of our messages?

If you click on the number it will put in a specified address in the address box and bring that post to the top of the page. And so the address can be copied for other references.

e.g. http://www.cruisersforum.com/forums/...tml#post923317

[mikereed100]

Lots of great ideas here, but in the interests of low cost and simplicity, why not just put an electric pump, sized to your engine's specs, on the far side of the primary filter with a "y" valve to a "T" on the return line? Go sailing on a bumpy day and run the pump. It would have the side benefits of making priming easy and you would have a spare pump already in line.

[s/v Jedi]

Originally Posted by mikereed100

Lots of great ideas here, but in the interests of low cost and simplicity, why not just put an electric pump, sized to your engine's specs, on the far side of the primary filter with a "y" valve to a "T" on the return line? Go sailing on a bumpy day and run the pump. It would have the side benefits of making priming easy and you would have a spare pump already in line.

You must keep the Racor between tank and pump.

cheers,
Nick.

[Bash]

Many responders to this thread seem to have missed the OP's statement, "...I know there is a large quantity of water in the tank along with a lot of debris and all the microbials that inhabit such an environment."

If there is indeed a large quantity of water in the tank, it will be located at the bottom of the tank. If diesel floats on water, which it does, than water will sink in diesel. You'll need to rig a separate pickup line in order to suck this water through your pump. Your filtration system will need a large water separator, which means you won't be able to make do with salvaged auto parts.

I disagree with the anti-Racor sentiment expressed by one of the posts. There's a good reason that Racor makes the filtration systems for the majority of commercial as well as recreational boats. I paid a couple thousand dollars for the dual Racor system on my boat because it was the best thing out there. Yes, it's possible to purchase something less expensive, but once you're offshore you'll appreciate gear built for the job.

[rebel heart]

Originally Posted by speedoo

Yes, I have to agree. Of course the best situation is to have both clean fuel and a clean tank. But even if the tank is dirty, polishing the fuel is certainly going to help, and of course polishing the fuel will remove some of the dirt from the tank that has been picked up by the fuel. And moving the polished fuel to a temporary tank will facilitate cleaning the tank.

Polishing fuel does nothing for the slime that builds up all along the tank walls. Burn through old fuel, disposal costs for the gunk are about $0.25/gallon at the fuel docks here. Get the tank empty and go at it with paper towels until the towels come back as white as possible.

Polishing fuel is up there with holding a dirty dinner plate under a faucet and expecting it to get clean. You need light abrasion and force to knock the crap off.

[Cheechako]

Originally Posted by s/v Jedi

You must keep the Racor between tank and pump.

cheers,
Nick.

On a really mucky system I suppose you need a prefilter before the pump. (?) Normally, a filter is after the pump. Most all the hydraulic systems I've been exposed to insist the filter is after the pump. Most pumps push better than they pull, as the filter flow rate decreases, the pump can still push the fuel through. Imagine putting a pump after your Reverse Osmosis watermaker membranes..

[zeehag]

filtering fuel to polish it is able to work when you MANUALLY clean the tank so it is able to receive clean fuel and function as if you never had dirty fuel in it. there are places in this earth wherein the fuel obtained is NOT clean-- you will find that, out here in the real cruising world, you get bad and dirty fuel. polishing may save the boat from rocks as there will be a failure of the engine when that dirty fuel comes in to block your system and lines.
fuel starvation is only massive in heavy seas and near rocks. be safe---is not difficult to install a system into your boat for this job---have fun and enjoy your boat.