Diesel bug

[hardlife]

Hi, I have a Princess 460 which is currently in Croatia. We picked up bad fuel earlier this year. The engineers killed it with additives, but in rough seas, the bug 'sludge' blocks the fuel filters. Any suggestions, please, on what to do.

Hi, A big SORRY for not coming back to all of you for your suggestions...This Xmas has been very hectic with all the family visiting for 3 weeks...and the phone line with internet going down! Anyway, I've been bowled over by your inputs. Thanks to all of you, I can now give some very clear suggestions to the engineer in Croatia.
Have a GREAT boating year.
It's a HAAARD LIFE!
Warm regards
hardlife

 

[rafiki_]

Hardline, a very warm welcome to the forum. Diesel bug can be killed off with additives like Grotomar or Marine 16. However if it is very stubborn, you may need to have the fuel "scrubbed". This is a process whereby the fuel is pumped through a filter process until the bug is eliminated. There are mobile crews in the UK who will do this, but I have no idea about Croatia. There are a few on hee who also moor in Croatia who may have a better idea about local services. In your case it sounds like there is still some bug present in the bottom of your tanks. If you can get a symphony to this region, you might be able to suck out the infected area.

 

[volvopaul]

Hi, I have a Princess 460 which is currently in Croatia. We picked up bad fuel earlier this year. The engineers killed it with additives, but in rough seas, the bug 'sludge' blocks the fuel filters. Any suggestions, please, on what to do.

You can make your own fuel polishing system from a couple of racor or separ filter unit and a gear pump made by jabsco. Basically just make up the filters inline and suck from the lowest part of the tank returning the fuel to the tank. A few friends have ther own home made system , they just leave it switched on when ther at there boats, after a few hours running remove the filter elements to check for debris, one owners boat and the bug really bad, after a few Hours running the first fliter was totally blocked, new element and it was up and running again. For a real pro job it's best to cut access hatches in the type of the tanks and suck from various places to scoop up the debris in each tank . Over here the job is only as successful as the company that carries the job out.
I have seen some negative results because the hatches are not possible to cut out because of the design of the boat. I know the 460 well, it's grp floor above your tanks so part of that will have to be cut out the gain access to cut hatches in each tank. It can be done but I'm not sure where in your country. I try the filtering if possible going down the DIY route.
Racor/ parker filtration can give advise as what to buy, as I said two stage filtration wil be better than a single one, the racor 500 units will do the job along with a jabsco gear pump, 12 volt, as a test you could plumb in into your existing separ filter units with a T piece of disconnect the outlet pipe from the filter to the engines primary pump, the Princes 460 is on 15 mm rubber hose so pretty easy to rig up, a simple length of hose to the deck filler will return it or again T into the fuel line return from the injection pump, again on 15 mm hose.

 

[kashurst]

as per previous posts. when you have flushed/filtered the tanks until the filter stays clean, strip and clean the onboard separ/racor/whatever filter housings too with petrol. I had similar a few years back and a big blob of bug stayed trapped inside the separ housing. If cutting hatches is a no - go take out the fuel senders - that will give good access and put a length of 15mm copper pipe on the end of your hose and use it like a jet washer around as much of the insides as it will reach. Then lots of Grotomar etc and carry spare filters.

re pump - have a look on ebay for a fuel transfer pump - they are very effective

 

[Hurricane]

We had a reasonably large attack of the bug - I never used to treat the fuel - now I do - every time.

Our Princess has small sumps with drain cocks at the bottom of the tanks.
It would be worth checking if they did the same when they built the 460

To get rid of the bug, we drained and discarded a few gallons of the bug contaminated fuel from the bottom of each tank.
i.e. got rid of as much as we could.
The tanks were about one third full at the time.
Each of our Separ prefilter sets (including the generator) were fully stripped and cleaned using a strong mix of Marine16 and clean fuel.
We then opened the access panels on the top of each tank.
Made up a very strong mix of Marine 16 treatment and using a pump, sprayed about 20 litres of it into each tank through the access hatches.
There are, of course, baffels in the tanks but it was possible to spray around the inside of the tank and cover most of the inside.
Then, on each tank, we connected a hose from the sump drain cocks to a pump and circulated/sprayed fuel for a few hours on each tank.
The idea was to circulate/mix the Marine 16 into the existing (relatively clean) fuel.
I did buy a cheap Racor filter from Ebay which I had intended to use in the pumped lines but in the end, I didn't use it.
After speaking to a very helpful guy at Marine 16, we decided that mixing the additive well would do the job.

There are two methods of treating the bug - you should check and see which method was used in your case.

I'm not a chemist but one method which is popular is to emulsify any water into the fuel.
Being an organic creature, the bug needs oxygen to survive - by removing the water, you remove any oxygen so it cannot live.
I believe that Fuel Set is a product that does this.
I've gos tome on the boat but I've never used it.

The other method is to actually kill the bug with a biocide - weed killer by any other name.
This is what we did. Marine 16 kills the bug rather than prevent it.
At the time, I also did a little test - I took some of the really bad contaminated fuel that I had first drawn off sumps at the bottom of the tanks.
I put the contaminated fuel into a clear used plastic water bottle (like the ones you get drinking water from the supermarket) - treated it with some Marine 16 and left it for 72 hours.
After only 48 hours, the bug had completely gone.

Finally, the guy at Marine 16 convinced us to refill the tanks and add some of his "Complete Treatment".
This is a pink coloured liquid but acts a a bug killer/treatment and lubricates the components in the fuel circuit - pumps injectors etc.
Apart from being a bit expensive, I didn't see a downside to doing this "Complete" treatment and by then we were leaving the boat for the winter so it seemed a good idea.
I seem to rember that we used the boat and went a few miles down the coast to fully flush the new treated fuel through the engines.

As said above, Grotomar is an equivalent product to Marine 16.
I believe that Marine 16 is cheaper though.

We were lucky, our Separ pre-filters seemed to have trapped all the bug before it got to the main engine fuel filters.

Since the attack by the bug, we have always treated our fuel and now there is no sign of the sludge/bug anywhere on the boat.

I'm afraid that I blame the bureaucrats in the EU.
In the Med, we are forced to use ULSD - Ultra Low Sulphur Diesel with about 7% Bio Mix
My theory is that the sulphur tended to kill the bug.
And by adding the Bio Fuel, you are giving it you are making it a better environment for the bug to live.

My advice to anyone though is - treat your fuel - either method seems to work.
The Marine 16 method is not an expensive operation - especially once you have got it under control - a very small amount goes a long way (from memory - 100ml per 2000 litres).

 

[Freebee]

you don't actually need any fancy filters to remove dead bugs,water and sludge, you need to let the tanks settle, no engine running or anything that will stir up the tank bottom.

If you have a tank drain valve just open the drain and let the crud flow out till the fuel runs cleanish. If you don't have a drain you need a means of sucking the crud up from the bottom of the tank, this could be done through an inspection hole or perhaps fuel level gauge sender. You need some kind of a pump, this could be a pela vacuum sump drain pump and a rigid suction hose or some metal tube that can be positioned in the bottom of the tank and just suck out the tank bottom until the fuel runs clear.

 

[david_bagshaw]

To add to the good advice above, if the tank is carefully drained, most of the fuel can be treated and returned later, but with an empty tank a wet vac can be used to suck up most of the bug sludge. Hot water with washing powder and bleach does a good job of killing residual particles. Paper stripper steamer might be good connected to a small pipe, but never used one personally.

dont forget this is a living thing so however clean it looks biocide is definitely needed, as some lurks in a pipe, bend, corner etc

 

[hardlife]

Hi...Thanks for the welcome....and for the advice. Much appreciated.

 

[Wino]

I was advised to use 'Jeyes Fluid' to kill the bug - much cheaper and just as effective. Has any one else used it?

 

[Hurricane]

I was advised to use 'Jeyes Fluid' to kill the bug - much cheaper and just as effective. Has any one else used it?

I think it is debatable whether Jeyes Fluid is any cheaper.
I don't know how much you would put in the tank but with Marine 16 or Grotamar, you only need a tiny amount.
And its only fifty quid for a huge bottle of the stuff - which is designed for the job.

 

[rafiki_]

I think it is debatable whether Jeyes Fluid is any cheaper.
I don't know how much you would put in the tank but with Marine 16 or Grotamar, you only need a tiny amount.
And its only fifty quid for a huge bottle of the stuff - which is designed for the job.

£9 at Force 4 buys enough to dose 2000litres. Pretty good VFM for me, and with £1000 + worth of fuel in my tanks, I am not going to sling Jeyes fluid in!