diesel bug?

[churchward]

That assumes that oxygen cannot dissolve in diesel, which is not the case. Any sloshing around in the tank will help bring oxygen to the water layer.

Some yes but it will still be a very low oxygen environment. The ratio of water to diesel can be very low. In a narrow boat tank there can be 200 litres of fuel above the water layer of only 2 or so litres. Sloshing about won't make that much difference. It also seems that growth is more likely in a still tank so a boat moored for the winter months is more likely to suffer the bug than a boat constantly used, for all sorts of reasons. Condensation in the tank will be one and a steady state environment another.

[Guest]

Some yes but it will still be a very low oxygen environment. The ratio of water to diesel can be very low. In a narrow boat tank there can be 200 litres of fuel above the water layer of only 2 or so litres. Sloshing about won't make that much difference. It also seems that growth is more likely in a still tank so a boat moored for the winter months is more likely to suffer the bug than a boat constantly used, for all sorts of reasons. Condensation in the tank will be one and a steady state environment another.

I believe that this is the danger time.

[mango]

Some yes but it will still be a very low oxygen environment. The ratio of water to diesel can be very low. In a narrow boat tank there can be 200 litres of fuel above the water layer of only 2 or so litres. Sloshing about won't make that much difference. It also seems that growth is more likely in a still tank so a boat moored for the winter months is more likely to suffer the bug than a boat constantly used, for all sorts of reasons. Condensation in the tank will be one and a steady state environment another.

Are the bugs in the list provided by PaulG anaerobes?

[churchward]

Are the bugs in the list provided by PaulG anaerobes?

I don't know you will have to ask him.

[peterboat]

Thats what I am wondering too.

 

Can the bug be in the diesel fill up points tanks, and is their a special diesel bug inline filter that could be fitted to a narrowboat fuel line ?

 

I found this filter/polisher below which apparently stops the bug sludge reaching the engine but I can find a link to buying one.

i have one of these on my boat it traps water and dieselbug as yet its not done either but its there ready to pounce when needed

Your 'diesel' must contain a lot of dirty water.

not my diesel a customers he brought in the non running car we fixed it as i said tank and filter black gunge so steam clean blow fuel lines out good as new

[robert anthony]

OK, so been down to the boat today. It's been moored up for 24hrs so plenty of time for everything to settle in the tank.

I took a 2 litre sample from the lowest corner of the tank. Surprisingly there was only a small amount of water (about 200 ml)

The diesel itself was pretty much clear apart from the odd fluffy type of particle in it. Diesel was red, not pink.

There is obviously some diesel bug in there but nowhere near as bad as the pics I've seen online.

I pulled the old fuel filter apart and contamination wasn't to bad there either.

However, the fuel line itself was blocked pretty much all the way through. The fuel line is made from 1/4 inch copper tube and when I removed the fuel pick up line from the tank I found that was also a piece of 1/4 inch copper pipe which ended about 1/2 inch from the bottom of the tank. To be honest I was expecting something a bit more substantial with a gauze on the end to stop bits being sucked into the fuel line. Is this the norm? I'm thinking if I fit a larger diameter fuel line and pick up I can trap any contamination in the filter and treat the tank with a biocide.

 

 

 

[craftycarper]

OK, so been down to the boat today. It's been moored up for 24hrs so plenty of time for everything to settle in the tank.

I took a 2 litre sample from the lowest corner of the tank. Surprisingly there was only a small amount of water (about 200 ml)

The diesel itself was pretty much clear apart from the odd fluffy type of particle in it. Diesel was red, not pink.

There is obviously some diesel bug in there but nowhere near as bad as the pics I've seen online.

I pulled the old fuel filter apart and contamination wasn't to bad there either.

However, the fuel line itself was blocked pretty much all the way through. The fuel line is made from 1/4 inch copper tube and when I removed the fuel pick up line from the tank I found that was also a piece of 1/4 inch copper pipe which ended about 1/2 inch from the bottom of the tank. To be honest I was expecting something a bit more substantial with a gauze on the end to stop bits being sucked into the fuel line. Is this the norm? I'm thinking if I fit a larger diameter fuel line and pick up I can trap any contamination in the filter and treat the tank with a biocide.

 

FOTDDFD.JPG

 

i agree with you, I would just clean the pipe work, stick a biocide in the tank and buy half a dozen filters to change on a monthly basis, my old tipper experienced much the same as you and this is how I've sorted it,it runs better with each tank of fresh fuel I put in, good luck

[robert anthony]

Cheers Crafty, so after 5 pages of waffle it would seem that Churchward was right in post No. 2

Edited October 26, 2015 by robert anthony

[mango]

The fuel line is made from 1/4 inch copper tube and when I removed the fuel pick up line from the tank I found that was also a piece of 1/4 inch copper pipe which ended about 1/2 inch from the bottom of the tank. To be honest I was expecting something a bit more substantial with a gauze on the end to stop bits being sucked into the fuel line. Is this the norm? I'm thinking if I fit a larger diameter fuel line and pick up I can trap any contamination in the filter and treat the tank with a biocide.

It's normal to have a dip-tube an inch or more from the base of the tank. If it had a filter at the end, that would block up easily and it would not be easy to clean, whereas it is easy to replace a filter.

[robert anthony]

It's normal to have a dip-tube an inch or more from the base of the tank. If it had a filter at the end, that would block up easily and it would not be easy to clean, whereas it is easy to replace a filter.

Diesel Bug article from RCR.pdf

[peterboat]

Diesel Bug article from RCR.pdf

cheers as i said since biodiesel on the go we have had problems with low use cars and diesel bug its poo

[mango]

Diesel Bug article from RCR.pdf

"Diesel bug is the term given to the enzymes, bacteria etc that live of the water in diesel …" Nonsense.

 

Edit to add: I very much doubt that a gauze on the end of the dip-tube would have avoided the blockage you described at the start of this discussion. It is likely that a biofilm has built up on the inner surface of the pipe over time, until it was completely blocked. In the same way, hot water pipes can become blocked by gradual build up of limescale.

Edited October 27, 2015 by mango

[Midnight]

A boater pulled up at our Club this summer and told me he had had to change the fuel filter every 4 days to keep the engine running and asked me about diesel polishing. A bit sceptical I enquired further and asked if he had changed both filters. He told me there was only one but looking into his engine bay I could see another - a wasp filter which he hadn't realised was there so hadn't serviced it for the 7 years he had the boat. Taking it apart the wire gauze and chamber were full of a opaque jelly substance. Not diesel bug but was that the biofilm mentioned by Mr Mango?

[robert anthony]

It's not biofilm that has built up over time. It was stringy algae like substance (similar to what you get in ponds during the summer) plus the engine was running perfectly right up until it started spluttering and died. What I think has happened is that the blockage occurred at the end of a 10 day cruise (mainly on rivers) so I've used a fair bit of diesel. That's resulted in any bug in the diesel becoming concentrated in the remaining diesel and getting sucked into the fuel line.

The reason I was asking about the size of the fuel line is - if the fuel line gets blocked before the crud gets to filter the I won't be able to filter it out using the boats filters. That means I'll have to drain the tank but there is at least 150 litres still in there so I'd rather not if possible.

[mango]

It's not biofilm that has built up over time. It was stringy algae like substance (similar to what you get in ponds during the summer) plus the engine was running perfectly right up until it started spluttering and died. What I think has happened is that the blockage occurred at the end of a 10 day cruise (mainly on rivers) so I've used a fair bit of diesel. That's resulted in any bug in the diesel becoming concentrated in the remaining diesel and getting sucked into the fuel line.

The reason I was asking about the size of the fuel line is - if the fuel line gets blocked before the crud gets to filter the I won't be able to filter it out using the boats filters. That means I'll have to drain the tank but there is at least 150 litres still in there so I'd rather not if possible.

The slime is bacteria or fungi embedded in polysaccharides that they have excreted. When it sticks to surfaces it's referred to as a biofilm. Treatment with biocide should stop growth of the 'bug' but it will not remove what is in the tank or on the walls. I pump out a sample of what's in the bottom of the fuel tank and after five years, all traces of bug have gone.

 

Best of luck.

[robert anthony]

I think I've come up with an idea that may work. I can't empty the tank as I've not got anywhere I can store 150 litres of diesel so I've found an old fuel pump and inline filter in the shed. If I suck out the diesel through the filter from the lowest point of the tank and return the filtered diesel to the opposite side of the tank I reckon that should clear the bug out of the tank. I've ordered a pack of 10 inline filters so hopefully that should be enough. Once the filters have stopped blocking up I can treat the tank with biocide. Fingers crossed it works.

 

 

[mango]

I think I've come up with an idea that may work. I can't empty the tank as I've not got anywhere I can store 150 litres of diesel so I've found an old fuel pump and inline filter in the shed. If I suck out the diesel through the filter from the lowest point of the tank and return the filtered diesel to the opposite side of the tank I reckon that should clear the bug out of the tank. I've ordered a pack of 10 inline filters so hopefully that should be enough. Once the filters have stopped blocking up I can treat the tank with biocide. Fingers crossed it works.

 

FOTC63 (1).JPG

 

If you find that the filters soon become blocked up, try pumping from the bottom corner of the tank into a clean container, decant the clear diesel back into the tank and repeat. It might help get rid of the worst. The usual recommendation is to empty and steam clean tanks but I know people who have not found this necessary to clear the bug.

[Guest]

If you find that the filters soon become blocked up, try pumping from the bottom corner of the tank into a clean container, decant the clear diesel back into the tank and repeat. It might help get rid of the worst. The usual recommendation is to empty and steam clean tanks but I know people who have not found this necessary to clear the bug.

Would there be any advantage in refilling via a filter element in a funnel after decanting? Just a thought, as I have seen filter material on ebay etc.

Edited October 28, 2015 by Guest

[robert anthony]

If you find that the filters soon become blocked up, try pumping from the bottom corner of the tank into a clean container, decant the clear diesel back into the tank and repeat. It might help get rid of the worst. The usual recommendation is to empty and steam clean tanks but I know people who have not found this necessary to clear the bug.

That's not a bad idea, cheers.

 

Would there be any advantage in refilling via a filter element in a funnel after decanting? Just a thought, as I have seen filter material on ebay etc.

I see what you are getting at but I would have thought any particles that small would get taken care of by the biocide or burnt in the combustion chamber?

[mango]

Would there be any advantage in refilling via a filter element in a funnel after decanting? Just a thought, as I have seen filter material on ebay etc.

Sorry but I don't know. In my case it was easy to decant the clear diesel and any bug that went back was small compared with what remained at the bottom of the tank. From what I have read, diesel bug varies and it might be necessary to filter diesel to reuse it.