Fuel Polishing

[roetter]

Today I got a good look at what my fuel polishes can do for me. Last year I installed a simple polisher that I run almost every time I use the boat. All I need to do is press a button and watch the glass bowl at the fuel filter to see if anything shows up. Nothing showed up in the last 6 months. We are in the middle of winter (0 to plus 5 Celsius) in Victoria, BC, and my tank is only 3/4 full, so I expect water from the condensation. Two days ago I put some Diesel biocide into it. I did not expect ,ugh as the fuel would not get mixed as much as it would when fuelling and almost empty tank. However, I had gone for a sail two days ago.
Boy was I surprised when I switched the pump on. Within a few seconds a black cloud streamed into the glass bowl of the filter. I took a sample into a plaice container after about 2 minutes. I let it run for another 20 minutes.
Below a schematic of the system.
You can also find 2 videos about the process here:
2012-01-30 at 15-48-34.m4v - YouTube
and here:
2012-01-30 at 16-08-13.m4v - YouTube
The fuel filter is a Racor and the pump is an automotive diesel pump for about $50. I hooked it up to a free switch on my panel. Including cables, hoses and fittings it was less than $300.

[delmarrey]

Here's a good article>>> Marine Diesel Fuel Contamination Problems & Solutions

Adding the biocide may have broken up what sludge you have and allowed it to saturate the fuel and then getting filtered out.
Have you taken a look inside your tanks lately?

[Rhapsody-NS27]

If one does the polishing and cleans up the fuel from all the gunk, what is done to dispose of it? Take the contents to a shop/garage like disposing of oil? go somewhere to burn it up?

[s/v Jedi]

The gunk is in the filter which is handled like lube-oil filters.

Here is my article about the ultimate complete fuel system: http://www.sv-jedi.org/sv_jedi/2006/...fuel_syst.html



ciao!
Nick.

[captain58sailin]

I installed an inline centrifuge before my racors, I also made up a dual racor filter system that allows me to change the filters on the fly. I too use the 2 micron filter elements, same as the secondary on my engine. Clean fuel + clean oil + clean air = diesel engines lasting a long time with no troubles. The high volume centrifuge cost me $750, which seems like a lot, but at $8 to $14 dollars per racor, it doesn't take long to save the cost. I also use and algaecide, and treat my fuel with Power service, and keep the tanks full. I do not want a fuel problem when I am 1000 miles offshore, and when closer to shore even more.

[Lagoon4us]

Originally Posted by s/v Jedi

The gunk is in the filter which is handled like lube-oil filters.

Here is my article about the ultimate complete fuel system: A new fuel system for Jedi (English) - s/v Jedi



ciao!
Nick.

+1 there....

[roetter]

Originally Posted by Dan_78

If one does the polishing and cleans up the fuel from all the gunk, what is done to dispose of it? Take the contents to a shop/garage like disposing of oil? go somewhere to burn it up?

Our marina has a shed with drums for used oil, bad fuel, as well as containers for fuels filters, oil canisters rags and so on. It all gets properly disposed. Your marina should do the same.

[Dockhead]

All this has made me realize that I haven't thought about my tanks in a long time. I had them professionally cleaned when I bought the boat 2 1/2 years ago, and I installed dual Racors at the time (the PO had never bothered) with 10 micron elements.

I change the fine secondary filter on the Yanmar engine every year. It's in a metal housing so I can't see whether it's dirty or not.

Part of my every day routine upon starting up the engine is to shine a flashlight through the Racor filter bowls -- in all this time I've never seen a speck of dirt or a drop of water. And observe the vacuum gauge after the engine is started.

I've never changed the filters -- they are the original elements which came with the Racors when I bought them.

I wonder if I'm being cavalier about it, or whether it's just a question of different fuel quality in different parts of the world. Maybe it's time to have the tanks cleaned again just in case ($$$).

Nick, that system is a masterpiece. I will eventually imitate some elements of it, I think, especially if I ever end up cruising in warmer and dirtier climates.

[ErikFinn]

I'm trying to plan a suitable DIY fuel polishing system for my boat but have some unresolved questions remaining and I would invite opinions and advice from you more experienced guys please.
Below are some of my thoughts, please comment if you find them good/bad:


1) "Portable" system?

Pros: takes less space in the engine room. Could polish both the Main tank and the Aux tank (would just need to change the plumbing obviously).

Cons: I'm a liveaboard and don't prefer more stuff in the boat as I already have too much.


2) Dedicated (separate) or combined system?

Should I have this as a completely separate system from the engine's primary filter? In this case I would need a dedicated filter for polishing only (not use the engine's primary filter)

Or with a "combined" system if I can use the Primary filter for polishing I would not have to worry about installing an additional filter and finding space for that also.

The idea of using the same filter for polishing and engine running sounds inviting (would save space, money) but are there factors that make this a bad idea? The way to do the plumbing would be to add a valve after the Primary filter to direct fuel either to engine or to the polishing pump and back to the tank.


3) What pump?

I'm torn between a 12V pump and a 240V pump. At the moment I'm thinking to only polish at the marina. At sea I should really preserve all the amps I have, and not run a 12V motor with high amp draw.
Should I consider installing both pumps?


I have a 50HP Perkins diesel, main tank is 170L, Aux is 140L. I'm getting a fairly large Racor (bigger than the "500"-series) or Griffin dual turbine unit soon to use as my primary filter. At the marina I estimate not to polish every day, maybe once a week for a few hours.

Thank you,
Erik

[noelex 77]

An old thread, but fuel polishing is popular topic.

Ideally the pickp for the polishing should be in a different location at the very bottom of the tank with its own dedicated filter.

I would not use the main engine filter, but you could use a filter that could also be used as a switch over filter if the main engine filters clogs. This is not ideal, but as long as you have a vacuume guage its a reasonable compromise, but not if the pickup is at the bottom of the tank, as it should be.

The main benefit of polishing is in, or just after a sail in seaway, or at a rolly anchorage. So a 12v pump is better.
The system works best if you polish a lot fuel so practicalities like a quiet efficient (in terms of electricity consumption) pump are important, but there are plenty to choose fom.

[noelex 77]

Originally Posted by Dockhead

I change the fine secondary filter on the Yanmar engine every year. It's in a metal housing so I can't see whether it's dirty or not.

Its worth taking a couple of minutes to cut it apart with a hacksaw.

Originally Posted by Dockhead

Part of my every day routine upon starting up the engine is to shine a flashlight through the Racor filter bowls -- in all this time I've never seen a speck of dirt or a drop of water.

Occasionally try decanting some in clear glass jar. Shaking it ip this shows up minor suspended particles much better than the bowl,( but the bowl is good daily check).
Minor suspended particals in my fuel (and a primary fuel filter that was slightly dirtier at the 12month mark) is what first made me install a polishing system. After a month or so of using the polishing system the fuel went back to completely transparent and has stayed that way.

[RaymondR]

Over the years I have evolved a system which seems to work pretty well for me.

In 2001 I started cruising in the tropics and refueling in marinas. I had not had a fuel bug problem until then which was probably because I generally refueled from service stations via gerry cans.

I laced my fuel tank with biocide but was still experiencing excessive filter use due to the black sludge remaining in the fuel tank. To fix this problem I bought a 12v Johnston impeller pump, made up some felt bags which I fastened to the end of the discharge from the impeller pump, pushed the bag into a 20L container from which I had rigged a return line and circulated the fuel tanks for a couple of hours. I recovered about three bag fulls of the black sludge and did not have a problem for the next couple of years.

When the problem re-occurred I decided I needed a more permanent installation so went in search of a large filter housing; at least a couple of litres. These were plentiful but costly and none of them were see-thru, they also used disposable filters which were costly and my cheap, reusable felt bags had worked so well I fabricated a housing using alloy and a glass spaghetti storage jar. This all worked well for a number of years.

A couple of years ago I changed from a Yanmar 3GM30 to a Kubuto V2203 engine which held quiet a bit more sump oil. I had been using a small Finsbury hand pump to change the engine oil but this was pretty tedious with the extra lift required with the new engine also one of the downsides with the Johnson impeller pump was priming it as my fuel tank is down in the keel and if the fuel is low quiet a bit of lift is required.

The solution was to replace the Johnson pump with a 12V gear pump and plumb the Finsbury manual pump on the gear pump outlet with a bypass and a check valve. This works so well that I now do a regular water-in-tank check by turning on the gear pump, giving the Finsbury a few strokes to prime the gear pump and watch the fuel circulate through the spaghetti storage jar. The spag jar/felt bag separator has a bottom draw-off tube with a small metering valve from which I can collect a sample in a plastic bottle to check for water.

I also use the system to suck out the Kubotu sump for oil changes.

Biggest expense was the 12V gear pump which cost about A$230.

[ErikFinn]

Originally Posted by noelex 77

An old thread, but fuel polishing is popular topic.

Ideally the pickp for the polishing should be in a different location at the very bottom of the tank with its own dedicated filter.

I would not use the main engine filter, but you could use a filter that could also be used as a switch over filter if the main engine filters clogs. This is not ideal, but as long as you have a vacuume guage its a reasonable compromise, but not if the pickup is at the bottom of the tank, as it should be.

The main benefit of polishing is in, or just after a sail in seaway, or at a rolly anchorage. So a 12v pump is better.
The system works best if you polish a lot fuel so practicalities like a quiet efficient (in terms of electricity consumption) pump are important, but there are plenty to choose fom.

Thanks for your reply Noelex,you are always so quick and informative to reply.
Yes, I didn't think would warrant a new thread.

Re the fuel pickup-point; I was thinking to use the original outlet at the top of my tank as this should have an internal pipe to the bottom or near to the bottom of the tank, right? Otherwise one couldn't use all the diesel in tank.. And use a dual Racor turbine 900 or 1000, or equivalent. These ones do have a vacuum gauge.

Re Voltage; yes I see, it does make sense in that respect to polish when the boat is a bit tossing and turning. This rarely happens in the marina.

What would you guys think of a pump like this Cospet 12V 14l/min Gear Pump? I checked their website and Google but could not find more specs. Would this be ok or too small/large for my tanks?

[noelex 77]

Originally Posted by ErikFinn

Re the fuel pickup-point; I was thinking to use the original outlet at the top of my tank as this should have an internal pipe to the bottom or near to the bottom of the tank, right? Otherwise one couldn't use all the diesel in tank.

Usually the engine pickup stops a couple of inches short of the bottom of the tank (depending on the design). This is done to stop the engine picking up water and crud at the very bottom of the tank.(at the expense of making some of the fuel capacity unusable)

Ideally the polishing system uses a pickup at the very bottom of the tank, because you want to pickup the water and crud with this system.

[noelex 77]

I use an old fuel transfer pump that came with the boat. It is of unknown make and model.
I wanted a spare and purchased a Walbro FRC-6, but I have not used it yet.