Fuel polishing

[Odysseus]

The last 4 years the BUG has become a major issue in France and I have been involved in towing boats, changing filters on boats the owners don't  understand, and explaining what the BUG does over time.

Last year I made a fuel polishing system for my boat and a system to take samples of fuel easily at any time. You will all do well to think of doing a similer thing.

I have always put fuel additive in the tank each time I fill up but I was surprised at the rubbish  that came out the first time I polished it.

The set up cost me less than £40 that's cheap for piece of mind, and was not difficult to put together. My system to check the fuel is pumping a hand bulb and taking a sample several times a year, it's easy takes 10 mins max. However I can only polish the fuel when the level in the tank has gone below the grommets in the tank see photos. I have modified the grommets in the tank to utilise the holes. Take grommets out put clear plastic pipe down to bottom of tank switch on and move pipe around the tank, return pipe into tank. Easy.

Hope this helps.

Odysseus
Bad 38

Hope this helps

[Scorcher IV]

Thats a great little set up, what type of filter is the small one in the black pipe on the right of the photo and how long does it take to polish the fuel or do you just leave it running?
Simon

[GeoffV]

I made a polishing setup and mainly use it to fill the main tank from cans.

I never fill the boat tank directly from the shore pumps only from the cans via the polisher. The fuel is always treated with marine 16 in the can and touch wood 18 years three boats later never had a problem. No water in, no muck in - fuel tank always clean on its annual check.

This was all prompted years ago by the stories of muck stirred up in the tank during bad weather killing the engine just when you needed it most!

[Odysseus]

The small filter in the first photo is just a common see through one I put in line for my Webasto that I fitted it uses on of the 2 grommets outlets.


The small filter in my polishing set up is just to stop the big stuff getting through and you can clean it as it's reusable, I also have one of these inline before the fuel shut off valve as it is notorious for blocking blocking as it's a gas valve.

Don't  listen to people who say their tank is clean, you will be amazed how much crap is in them even when you filter the fuel in it's a growth inside the tank.

I leave the pump running recirculation of the fuel back to the tank, but I have a rake around the bottom and corners when I first start. You can see the crap come up the clear pipe, it's the concealed BUG crap.

As I say you don't  have to do this, you choose.

Hope this helps

Odysseus
Bad 38

[Craig]

I can't see specialised fuel polishing systems in your average Bavaria as being of any use.

Approximately 40 times the fuel you use on a typical motor is returned to the tank. Multiply your fuel consumption by 40 and that's how much you are polishing through your filters with even a short motor.

Almost all Bavarias I have seen with a blockage are due to a blockage at the Fuel Cut-off switch as mentioned by Odysseus.

Get an inline strainer ( 4 euros) and put it in the line between the tank and the fuel cut-off switch. It will catch all the large lumpy bits that will stop your engine. Use an enzyme ( I use Startron) to break down the gunk. Gunk in the tank isn't going to hurt anything, and after a period of motoring, the enzyme will break it down anyway.

I have found that an enzyme treatment only works with warm diesel being recirculated. It does not work in cold tanks over winter.

If you are in Europe you have the additional problem of the FAME in the diesel waxing out at low temperatures. This is not supposed to happen until the temperature gets below -5 C. but I suspect it partially happens at higher temperatures.

I have spoken to both the Volvo dealer and the Bavaria dealer in Malta and they both confirm that they have not seen a boat stopped by bug if they had an in-line strainer installed before the Off-On switch. This is also in a country where cleaning tanks is a rarity.

Craig
"Shirley Valentine"
Gold Coast
Australia


 

[ITIL MAN]

Do you mean something like this.
https://www.ebay.co.uk/itm/2-x-Inline-LARGE-DIESEL-Fuel-Filter-Universal-6mm-8mm-Pipes-Oil-HGV-Plant-Farm-/400996750920
It’s low pressure so fitt8ng just before the fuel shut off would be quick to install.  I’ve never had any problem so far as mostly use fuel straight from vehicle pumps but sounds a simple effective precaution.

[Odysseus]

Craig, you are correct about the fuel recirculation fuel all the time the engine is running.
however the normal recirculation of the fuel does not deal with the crap in the bottom of the tank, until you have sucked up from the corners  and bottom you will not see it until your engine stops after the fuel has sloshed around the tank in bad weather just when you need your engine most.

Yes Europe is an issue and the cold storage over the winter, adds to the problem, there is an issue for all boaters now and any precaution you can take is good. The boat below had the tank pipe Inlet totally blocked so filters were no help at all.
as I keep saying it's your choice.

Have a chat with this guy below.

Odysseus
Bad 38

[dawntreader]

Do you mean something like this.
https://www.ebay.co.uk/itm/2-x-Inline-LARGE-DIESEL-Fuel-Filter-Universal-6mm-8mm-Pipes-Oil-HGV-Plant-Farm-/400996750920
It’s low pressure so fitt8ng just before the fuel shut off would be quick to install.  I’ve never had any problem so far as mostly use fuel straight from vehicle pumps but sounds a simple effective precaution.

That's the one I have fitted between the tank and switch. Easy to check and plenty of volume to allow flow of fuel.

[tckearney]

Thanks Dawntreader,  just ordered two.  £5.99 for two incl postage.  hopefully money very well spent

[dawntreader]

Thanks Dawntreader,  just ordered two.  £5.99 for two incl postage.  hopefully money very well spent

If the second is 'spare' then probably not  I've had mine in over two years and still very clean 

[tckearney]

Hi Again  just been down to the boat with a view to fitting the filter.   I assume best place to fit this is just as the hose leaves the tank and before the shut off valve. .  On my B42 this is a heavy steel platted reinforce rubber hose.   Do I just cut this and fit the filter with Jubilee clips?  I did note that there is already a filter on the feed to the diesel heater but is a soft hose.

[Odysseus]

Both my hoses are soft not braided, you will need good quality tin snips or like product for a clean cut.

I fitted a cleanable filter as when I did my polishing, raking around in the bottom of the tank it filled the filter.

Odysseus

[Craig]

The first photo attached shows diesel bug build up after 2 years in a Bavaria ( not mine) based in Malta. Never had tank cleaned ( 2002 model)  and never had fuel additives. The owner replaced the strainer for the next season.

I bought the same type of strainer for 4 euros after diesel bug stopped my engine on a trip from Sicily to Malta. Had a raisin sized lump clog the off/on switch. Second Photo shows the lump blown out with compressed air. After I installed a new strainer and ran the engine for about 1/2 hour I had some bug visible in my strainer. I put some Startron, an enzyme based treatment, in the tank and then motored for 9 hours back to Sicily. By the time I arrived back, there was no gunk in the strainer and the fuel looked clean. I then checked the tank and found it was clean. This was the second bug attack, the first 2 years before this on the first trip of the season in Turkey. Again, the bug blocked the off/on switch. It appears that almost all bug attacks in Europe happen early in the season. Cold, motionless tanks during the winter layups seem to grow bugs and possibly don't allow the enzyme type preventative treatments from working. I've had no problems in the 4 years since, bearing in mind that living in Australia means no winter layup, all year sailing and no FAME in the diesel.

Yachting Monthly had a great article on the efficiency of Biocide and Enzyme fuel treatments a few years ago. I bought Startron based on those tests.

I understand that some boats stop due to a blockage in the fuel pickup lines and most boats stop due to clogged filters but the small size of the off/on switch in Bavarias seems to catch bug before anywhere else. This type of strainer should give a good visual clue as to any problems before they arise. You will get enough Gunk out of one of these strainers to make a vegemite sandwich before your off/on switch is likely to be blocked.

Craig
"Shirley Valentine"
Gold Coast
Australia

[Odysseus]

That was exacly the problem I had before my polishing system the gas valve clogged.

However as I also said when I hoovered the conrners and bottom of the tank i could not believe the crap that came out, but it was the first I had done it.

Odysseus
Bad 38