Fuel polishing

[drew silverwitch]

Its that time of year again and I have been recieving offers of fuel polishing services for the start of next years season.
I may be wrong but surely this is just, run the fuel through a water seperator and filter as you empty or fill the tank and clean the tank out.
An electric fuel pump, fuel filter and water seperator mounted on a piece of ply comes to about £50 and I can do it myself for a couple of quid a year for new fuel filters, or am I missing something.

 

[lw395]

A more powerful pump agitates the tank more and gets more crud out.
But your idea is basically right.

 

[Trundlebug]

Its that time of year again and I have been recieving offers of fuel polishing services for the start of next years season.
I may be wrong but surely this is just, run the fuel through a water seperator and filter as you empty or fill the tank and clean the tank out.
An electric fuel pump, fuel filter and water seperator mounted on a piece of ply comes to about £50 and I can do it myself for a couple of quid a year for new fuel filters, or am I missing something.

You're absolutely bang on.
That's exactly what I did a few years ago. Bought a filter head (the most expensive part IIRC), fuel pump and filter, together with a length of fuel hose. Bolted the bits to a couple of pieces of plywood, with a switch, job done.

It's saved me a fortune and cleaned up my fuel system no end. I now no longer need to change my boat's fuel filters for several years.
Fleetguard filters were my filter of choice, because they're better value than the Parker Hannifin type that everyone talks about, although the filters perhaps aren't as widely available you can get them if you know where to look (diesel centres, fuel filtration specialists, truck motor factors). I think replacement filters are about £11 to £15 each.

Worth phoning Fleetguard technical helpline for advice as to the best type for your needs.

Beware of over simplification though. You will need better filters than standard, because proper Fleetguard (and some others) filters take out dissolved moisture down to fractions of a percent. That's what the boat's separator and standard filters won't remove.

 

[Yngmar]

 

[lpdsn]

I built my own very primitive one too. Just an electric pump, motor bike filter and rubber hose. Just pump out to cans then back in. Use it whenever filling from cans.

When the tank is almost empty I can arrange it to cycle the dregs in the bottom of the tank. The fuel going back in stirs up the crud so it can be filtered out.

I think the professional fuel polishing services are mainly for MoBoers who might have a good few hundred litres to clean.

 

[lw395]

It may be worth having a pre-filter that can be cleaned and re-used.
This sort is cheap but does not hold ever so much crud:
http://www.ebay.co.uk/itm/3-8-Alumi...125907?hash=item2c937edd13:g:4fcAAOSwcu5UMmRY

 

[Pete7]

Might be worth draining and having a look inside the tank before you start filtering anything. Could be spotless and a waste of time or look like the photo below and filtering won't be enough, a 2 inch wallpaper scrapper will be needed. The filter below was cheap enough to build and may have worked if the tank hadn't been so bad.

 

[lw395]

A tank on a friends boat looked a bit like the above.
We could not easily get inside it so we made a sort of flail, a bit of old rope on the end of a fibreglass rod batten, stuffed it down the filler and spun with an electric drill.
It loosened enough crud that we thought the engines filters would cope with what was left.
Not perfect, but no problems in the 4 years since then.

If the crud is not moving under severe agitation, it will probably not move in a normal season.
You have to balance effort vs reduction in likely problems. Different people will draw the line in different places.
So long as a piece of crud is more likely to get 'polished out' than block the engine filter you are winning. IMHO.

My view is that it's worth getting the loose crud and water out f the bottom of the tank. How much further you want to go is a personal choice.
I don't believe there is much point in getting tanks surgically clean once in 5 years, then filling it with French Marina Diesel and hoping, for the next 5 years.
Clean-ish and often does it for me.
YMMV as they say.

 

[Tim O]

I like the sound of building a simple cleaning system like this.

I presume the fuel pump is pulling the fuel through the filters......so a fuel hose into the tank, then into filters, then to pump, then outlet from pump into jerrycans or straight back into tank?

Anyone got a simple system diagram?

Gotta be simple for simple folk like me.....!

 

[lpdsn]

Anyone got a simple system diagram?

Gotta be simple for simple folk like me.....!

My Mk1 fuel polisher just uses rubber hoses through the inspection hatch.

1) hose stuck in tank, connected to filter.
2) short hose between filter and pump
3) hose from pump to be stuck back in tank, or into a jerry can

One day there might be a Mk2, in which case I'd take off from the fuel pipe and feed it back into the return pipe. It would require cocks and fittings for hose to bring in flows to and from jerry cans, but if I had a permanent installation I'd want to put cocks on the lines anyway.

Unless you can't actually get 8mm hoses into the tank, I'd suggest going for the Mk1 approach.

I put an on/off switch for the pump very close to the tank. That's been handy a few times.

It really is pretty simple.

 

[superheat6k]

It is important to draw through the filter on the inlet side of the pump. If you pump first it can break up the water globules into smaller parts that can then pass through the coalescing filter, other than that, then yes these are simple things.

Mine has a Holley 12v fuel pump, which has been going strong since 2007. I use a Baldwin separator filter from a chap selling them for bio diesel home brewers.

I have also installed draw off connections with instant dripless connectors, so I can pull from either tank low point or filter inlet, and discharge to these or the normal spill return. This also allows me to prime the main fuel pre-filters, engine filter, and to blow back through the pick up should I ever pick up a slug of crud. I can also balance the tanks.

But of most importance and so easily missed is the simple task of greasing the threads on the fuel filler cap, the primary point of water entry.

I run the rig for about an hour each month and find virtually nothing removed. i have not yet suffered a fuel filter blockage and do not plan to. Important to filter immediately after re-fueling - even the best sellers might have crud in the bottom of their tanks, and you don't know where their tank levels are when you fuel.

 

[rwakeham]

I have a DIY thing here I made for this, similar to another poster - cycle the fuel from the tank and back into the filler pipe. The tubing is long enough to agitate the tank. Seems to work fairly well. All parts sold as a kit by ASAP supplies

 

[Trundlebug]

Have a look at this thread from a few years ago

http://www.ybw.com/forums/showthread.php?314108-Fuel-Polishing&highlight=

 

[charles_reed]

Reading this thread has made me think outside the box.

My problem is I never have filter blockage, but I do have inlet pipe blockage, always after a boisterous sea and always involving having to dismantle the take-up pipe at the top of the tank, blow high -pressure air through it in reverse direction and out comes a pellet of tar.

In the past I've taken off the tank and steam-cleaned it.
First time I had about 2l of water and 6 litres of contaminated fuel when the tank was emptied, after 18 years use. The last time, after 5 years about 500ml water and 5 litres of contaminated fuel.
Being in the Med it's always high FAME road diesel (except N Africa).
Now I shall try a large bore pipe, down the filler and use the pick-up as a return (it's 6mm od).
Something that can be done during the annual refit.

 

[lpdsn]

Reading this thread has made me think outside the box.

My problem is I never have filter blockage, but I do have inlet pipe blockage, always after a boisterous sea and always involving having to dismantle the take-up pipe at the top of the tank, blow high -pressure air through it in reverse direction and out comes a pellet of tar.

I can really recommend the fitting of a vacuum gauge to give you early warning. Not expensive to do.

 

[lw395]

Reading this thread has made me think outside the box.

My problem is I never have filter blockage, but I do have inlet pipe blockage, always after a boisterous sea and always involving having to dismantle the take-up pipe at the top of the tank, blow high -pressure air through it in reverse direction and out comes a pellet of tar.

In the past I've taken off the tank and steam-cleaned it.
First time I had about 2l of water and 6 litres of contaminated fuel when the tank was emptied, after 18 years use. The last time, after 5 years about 500ml water and 5 litres of contaminated fuel.
Being in the Med it's always high FAME road diesel (except N Africa).
Now I shall try a large bore pipe, down the filler and use the pick-up as a return (it's 6mm od).
Something that can be done during the annual refit.

That is a very small pick up.
I'd consider making it bigger and/or arranging to be able to polish the fuel more than once a year.

 

[charles_reed]

That is a very small pick up.
I'd consider making it bigger and/or arranging to be able to polish the fuel more than once a year.

Considered and rejected as it involved surgery and welding on a diesel tank. A 6mm pick-up on an engine using about 1.5 litres/hr is more than adequate as most is being returned to the tank.
At least the small entry keeps the rubbish outside the fuel system.
Incidentally my motoring adds up to about 750-800 hours and my miles covered to about 1850nm a season, possibly rather more than many on this site.

 

[Piers]

There's two types of fuel polishing which i refer to as 'simple' and 'specific'.

Your engine overspill from the injector pump is the 'simple' method. The overspill has already been through the filters and is therefore constantly polishing the fuel.

'Specific' is where the crud at the bottom of the tank is intentionally stirred up, sucked through a large filter and returned at pressure aimed at the base of the tank to stir up the crud to be sucked though...' and so it continues until there's no more filtration to do. This specific' polishing is something vessels do not normally have a standard fit. Instead, it requires a company to be engaged to do this whilst dockside.

Overall, though, provided you treat you fuel at each fill-up, and as part of your winterisation checks, the only problem comes by taking on poor fuel normally encountered by filling up soon after the fuel station has had their tanks filled which has stirred up their own crud.

So, by treating your fuel as above, you engine will polish the fuel for you. If you have an existing problem which cannot be treated by additives, you need a dockside 'specific' treatment but make sure they will blast the base of the tank otherise it will nothing more than you engine.

Happy sailing with clean fuel!

 

[lw395]

There's two types of fuel polishing which i refer to as 'simple' and 'specific'.

Your engine overspill from the injector pump is the 'simple' method. The overspill has already been through the filters and is therefore constantly polishing the fuel.

'Specific' is where the crud at the bottom of the tank is intentionally stirred up, sucked through a large filter and returned at pressure aimed at the base of the tank to stir up the crud to be sucked though...' and so it continues until there's no more filtration to do. This specific' polishing is something vessels do not normally have a standard fit. Instead, it requires a company to be engaged to do this whilst dockside.

Overall, though, provided you treat you fuel at each fill-up, and as part of your winterisation checks, the only problem comes by taking on poor fuel normally encountered by filling up soon after the fuel station has had their tanks filled which has stirred up their own crud.

So, by treating your fuel as above, you engine will polish the fuel for you. If you have an existing problem which cannot be treated by additives, you need a dockside 'specific' treatment but make sure they will blast the base of the tank otherise it will nothing more than you engine.

Happy sailing with clean fuel!

Most yacht tanks in my experience pick up from significantly above the bottom of the tank.
As a result the engine pickup does sweet FA to remove water or crud until the tank is agitated in heavy seas, or until the rubbish reaches unmanageable levels.
If you keep the fuel reasonably free of water, by removing it from the very bottom of the tank to a reasonable standard, you won't need additives in your boat any more than you do in your car.
If you make the engine draw from the very bottom of the sump, the engine will indeed polish your fuel, but the down side is that taking on enough water to fill the filter will (at best) stop the engine.

I've helped clean a few tanks, most had loose crud which did not need 'blasting' from the tank.
One had a layer of stuff which nothing short of metal tools was going to touch, so we left it. It didn't cause a problem, it's the loose stuff that gets in the filters that is a problem.

 

[Piers]

Most yacht tanks in my experience pick up from significantly above the bottom of the tank. As a result the engine pickup does sweet FA to remove water or crud until the tank is agitated in heavy seas, or until the rubbish reaches unmanageable levels.

Quite agreed. No argument here.

If you keep the fuel reasonably free of water, by removing it from the very bottom of the tank to a reasonable standard, you won't need additives in your boat any more than you do in your car.

Sorry, cannot agree with this. There is always something in suspension in the fuel which is why it needs 'simple' polishing. Remember that diesel bug grows on the interface of water/diesel.

If you make the engine draw from the very bottom of the sump, the engine will indeed polish your fuel, but the down side is that taking on enough water to fill the filter will (at best) stop the engine.

Exactly, which is why fuel draw tubes do not reach the base of the tank.

I've helped clean a few tanks, most had loose crud which did not need 'blasting' from the tank.

You are fortunate indeed.

If you are fortunate to have a sump plus and can drain from the tank's bottom, then hallelujah. Many tanks do'nt, hence the need for 'specific' polishing if indeed you start to find water or a brown sticky 'crud' in the filters or filter bowl.

As I say, 'simple' is handled by the engine overspill. 'Specific' needs a dockside treatment. But if you have a drain plug, you should be OK and not need 'specific'.