Diesel Bug?

[Tony Brooks]

Did he add a biocide to the fuel after polishing? There have been cases where the bug has resurfaced after just polishing, probably from surface contamination in pipes etc. A member here had a hell of a job with that and eventually needed a specialist biocide if I recall correctly

[cuthound]

This was the contamination removed.

 

The round piece of metal is from the hole the boatbuilder cut to accommodate the fuel filler fitting!

 

 

 

 

 

31 minutes ago, Tony Brooks said:

Did he add a biocide to the fuel after polishing? There have been cases where the bug has resurfaced after just polishing, probably from surface contamination in pipes etc. A member here had a hell of a job with that and eventually needed a specialist biocide if I recall correctly

 

No, I had already added 200ml of Marine 16 (the "shock" dose rather than the "maintenance" dose) as soon as I found I had a problem.

 

I also ran the engine for an hour after polishing to ensure the biocide passed through the system and the recleaned the WASP filter and changed the engine fuel filter, so hopefully all of the fuel system has now been flushed with biocide treated fuel.

Edited July 27 by cuthound
Clarification and to add spaces between merged posts

[Ex Brummie]

The only problem i've had with fuel was when I added Exocet after the first reports of FAME red diesel. As I worked on oil boilers and other appliances, I've seen many cases of contaminated fuel and thought it might be a good idea. I've not used anything since particularly as I have a bubble stove, and vapourisers do not take kindly to additives.

[Bargebuilder]

The first thing I did on my last three boats was to install two, filter/water separators, plumbed in parallel with each other, straight after the fuel tank. Each filter has a fuel cock at its inlet and outlet, so either can be used independently of the other, and a blocked one can be isolated for easy and swift changing of the element without the need to even stop the engine. Very useful if you are crossing The Wash or doing the tidal Severn trip and the engine falters and stops through fuel starvation.

 

 

 

 

[NarrowboatTor]

Joe is a pretty knowledgeable chap, met him at Devizes marina and he helped me with a few queries.

Nice bloke, always up for a chat if you meet him 🙂

[Peugeot 106]

Any chance of telling us how much Joe charged?

[cuthound]

54 minutes ago, Peugeot 106 said:

Any chance of telling us how much Joe charged?

 

PM sent.

[Bargebuilder]

The consequences of diesel bug for lumpy water boaters can be life threatening, depending on where the engine decides to stop. Amongst such people, it is becoming more common for the fuel take off to be at the lowest point of the diesel tank; the sump if it has one. The reason for this practice is to remove all water from the tank, plus any sludge, before it has a chance to build up. Regular use of the engine keeps the tank clean and the tiny amount of water and sludge is collected by the primary fuel filter/water separator.

 

Diesel bug can multiply at incredible speed, so the annual removal of water and sludge is probably not going to be sufficient.

 

Also use Marine 16 or similar of course.

 

 

[DandV]

On 29/06/2024 at 00:21, cuthound said:

 

The engine is a Beta 43. The WASP filter is between the tank and the lift pump which in turn is before the filter mounted on the engine. I don't think the lift pump has a strainer fitted.

 

Today I pumped some fuel from the bottom of the tank and let it settle. It is a clear red colour.

 

There is some light brown sediment that usually isn't there which hopefully I have removed but I was surprised to find no trace of water. See photo.

 

I have added a shock dose of Marine 16 Diesel Bug Treatment and will leave it a few days before trying to pump out any further sediment from the bottom of the tank and then taking the boat for a trip.

 

If the problems persist then I will get the fuel polished, which hopefully will remove any remaining traces of sediment.

 

 

The bottom is water. Which is a remarkably high proportion of the shown sample.

That indicates either several years of accumulation of condensation from make up air as fuel is removed from the tank in normal operation or water ingress from a leaky fuel input, or excessive water input through through the tank vent. Too close to those leaking top gates on descent?

Water plus diesel is what grows bug.

Using a surfactant will only entrain the water in the fuel thus enlarging the water fuel interfaces in which bug grows.

You must get rid of that water, which is easiest done before you add any additives, as they suppress the simple mechanism of using the differing densities of fuel and water to separate the two.

Dosing without doing this is just adding snake oil.

Aviation tanks are checked daily for free water.

I removed about 50mils of water on my first water check on a seven year old boat, and then only traces, a few drops, every 250 hours of engine running. But a little more after having the aft deck flooded descending the Leeds and Liverpool. Presume it came through the vent. 

 

8 hours ago, Bargebuilder said:

The consequences of diesel bug for lumpy water boaters can be life threatening, depending on where the engine decides to stop. Amongst such people, it is becoming more common for the fuel take off to be at the lowest point of the diesel tank; the sump if it has one. The reason for this practice is to remove all water from the tank, plus any sludge, before it has a chance to build up. Regular use of the engine keeps the tank clean and the tiny amount of water and sludge is collected by the primary fuel filter/water separator.

 

Diesel bug can multiply at incredible speed, so the annual removal of water and sludge is probably not going to be sufficient.

 

Also use Marine 16 or similar of course.

 

 

Automotive fuel tanks have their take off point on the bottom of the tank so any water is entrained and dealt with by filtration/seperation  or just a bit of water injection with combustion.

Where the take off is above the bottom of the tank, then the tank becomes the primary settling chamber.

This is fine as long as you have a process in place to routinely check and drain this chamber, and if excessive water is encountered to in investigate why. Aviation fuel bulk storage is managed this way.

But without routinely removing water from the tank bottom it will continue to accumulate.

And will provide a breeding ground for diesel bug that will grow from the yeast spores normally present in the air that enters as fuel is extracted.

An accumulation of water will eventually rise to the tank take off level, if not extracted.

Any disturbance will then result in slugs of water and crud , instead of fuel heading off to the engine.

Lumpy water provides the disturbances  that guarantees that tank bottoms will on occasions reach the tank outlet. 

Hence it is imperative to routinely extract the non combustible, and filter blocking crud from the tank bottom 

 

 

[cuthound]

2 hours ago, DandV said:

The bottom is water. Which is a remarkably high proportion of the shown sample.

That indicates either several years of accumulation of condensation from make up air as fuel is removed from the tank in normal operation or water ingress from a leaky fuel input, or excessive water input through through the tank vent. Too close to those leaking top gates on descent?

Water plus diesel is what grows bug.

Using a surfactant will only entrain the water in the fuel thus enlarging the water fuel interfaces in which bug grows.

You must get rid of that water, which is easiest done before you add any additives, as they suppress the simple mechanism of using the differing densities of fuel and water to separate the two.

Dosing without doing this is just adding snake oil.

Aviation tanks are checked daily for free water.

I removed about 50mils of water on my first water check on a seven year old boat, and then only traces, a few drops, every 250 hours of engine running. But a little more after having the aft deck flooded descending the Leeds and Liverpool. Presume it came through the vent. 

 

Automotive fuel tanks have their take off point on the bottom of the tank so any water is entrained and dealt with by filtration/seperation  or just a bit of water injection with combustion.

Where the take off is above the bottom of the tank, then the tank becomes the primary settling chamber.

This is fine as long as you have a process in place to routinely check and drain this chamber, and if excessive water is encountered to in investigate why. Aviation fuel bulk storage is managed this way.

But without routinely removing water from the tank bottom it will continue to accumulate.

And will provide a breeding ground for diesel bug that will grow from the yeast spores normally present in the air that enters as fuel is extracted.

An accumulation of water will eventually rise to the tank take off level, if not extracted.

Any disturbance will then result in slugs of water and crud , instead of fuel heading off to the engine.

Lumpy water provides the disturbances  that guarantees that tank bottoms will on occasions reach the tank outlet. 

Hence it is imperative to routinely extract the non combustible, and filter blocking crud from the tank bottom 

 

 

 

For the last few years I have used a syphon pump to remove water from the bottom of the tank annually as recommended by @Tony Brooks.

 

I suspect I picked up the water and possibly the bug when I last filled up. I usually use a fuel boat but my regular one sadly died and no one had replaced him on a regular basis. Last time I filled up at a boatyard with an above ground tank. Interestingly my near neighbour also filled up there around the same time and has the same problem as have several boats that moor there.

[DandV]

2 minutes ago, cuthound said:

 

For the last few years I have used a syphon pump to remove water from the bottom of the tank annually as recommended by @Tony Brooks.

 

I suspect I picked up the water and possibly the bug when I last filled up. I usually use a fuel boat but my regular one sadly died and no one had replaced him on a regular basis. Last time I filled up at a boatyard with an above ground tank. Interestingly my near neighbour also filled up there around the same time and has the same problem as have several boats that moor there.

If several boats fuelled at the same source ended up with water, then that is very likely the source of your problem.

I would recommend temporarily increasing the frequency of your tank bottom scavenging until the residual water is drops rather then mils.

When I was an oil company engineer the thing I dreaded most was dealing with the aftermath of a trail of dead cars leading back to single site.

With underground tanks a leak in any of the connected  underground pipes, or a loose fill or dip cap could result in water ingress and justifiably upset customers. The advent of monitored double skinned tanks and pipework, and more aboveground secondary contained storage eliminated most problems. 

[john.k]

The fungii and bacteria spread through the air ...........any tank thats had bug in ,will have a billion spores ...........youd have to wash it out with chlorine bleaching solution and hot water ...............and the bug would be back in a couple of days from the atmosphere...............As Ive said before ,instead of spending money on 'fuel doctors'   ...Get Some Decent Filters....296 elements are all right on Fergie tractors ,no good on a boat...............and have tanks that can be drained regularly at the lowest point ....once a week .

[Bargebuilder]

A sailing friend of mine had diesel bug invade his tank, enough to stop the engine whilst underway. The cost of removing the fuel and polishing it and cleaning the tank came to around £500! He was told that diesel bug can double every 20 minutes, and if that is the case, then removing water and bug slime continuously would be very wise.

 

People who have never suffered an outbreak are understandably not particularly concerned, but bug attacks are becoming much more widespread and the cost of cleaning and polishing is considerable.

 

 

[DandV]

23 minutes ago, john.k said:

The fungii and bacteria spread through the air ...........any tank thats had bug in ,will have a billion spores ...........youd have to wash it out with chlorine bleaching solution and hot water ...............and the bug would be back in a couple of days from the atmosphere...............As Ive said before ,instead of spending money on 'fuel doctors'   ...Get Some Decent Filters....296 elements are all right on Fergie tractors ,no good on a boat...............and have tanks that can be drained regularly at the lowest point ....once a week .

And dead bug is equally effective at blocking filters as live bug. 

[Bee]

It seems diesel is becoming a troublesome fuel. I had a big problem with sludge/water cloudy  fuel etc. and ended up scrubbing out the tank and ditching a lot of fuel. The fuel had a different smell than diesel - like white spirit that had been standing with paintbrushes in it. Apparently this is a sympton of 'sticky fuel' so heaven only knows what was in the fuel that was in the tank. We only use road diesel as red is illegal in France so that was not the cause. There was water in the fuel though. I keep a litre bottle of fuel aside as it makes bleeding the engine easier and that too becomes discoloured after a year or more so I reckon that diesel really doesn`t keep very well at all. Incidentally I never fill the tank before winter - the tank is huge and I`m not scrapping 1,000 euros worth of fuel, anyway in a virtually sealed tank where is the condensation going to come from?. I think small, separate stainless tanks might be the way forward

[Bargebuilder]

6 minutes ago, Bee said:

in a virtually sealed tank where is the condensation going to come from?

Tanks breath in and out with change in temperature through the tank vent.

11 minutes ago, DandV said:

And dead bug is equally effective at blocking filters as live bug.

I should have added, that my friend who spent £500 on having his contaminated tanks cleaned has been using Marine 16 on every fill-up for years. This suggests that removing water continuously is a better preventative measure.

[peterboat]

50 minutes ago, Bee said:

It seems diesel is becoming a troublesome fuel. I had a big problem with sludge/water cloudy  fuel etc. and ended up scrubbing out the tank and ditching a lot of fuel. The fuel had a different smell than diesel - like white spirit that had been standing with paintbrushes in it. Apparently this is a sympton of 'sticky fuel' so heaven only knows what was in the fuel that was in the tank. We only use road diesel as red is illegal in France so that was not the cause. There was water in the fuel though. I keep a litre bottle of fuel aside as it makes bleeding the engine easier and that too becomes discoloured after a year or more so I reckon that diesel really doesn`t keep very well at all. Incidentally I never fill the tank before winter - the tank is huge and I`m not scrapping 1,000 euros worth of fuel, anyway in a virtually sealed tank where is the condensation going to come from?. I think small, separate stainless tanks might be the way forward

I have had sticky diesel it's a nightmare, in my big boat I now have real red diesel, it came out of a sea going boat so no bio content. I have used all the HVO I bought years ago and this red diesel powers the occasional use generator. 

[Tony Brooks]

1 hour ago, Bee said:

It seems diesel is becoming a troublesome fuel. I had a big problem with sludge/water cloudy  fuel etc. and ended up scrubbing out the tank and ditching a lot of fuel. The fuel had a different smell than diesel - like white spirit that had been standing with paintbrushes in it. Apparently this is a sympton of 'sticky fuel' so heaven only knows what was in the fuel that was in the tank. We only use road diesel as red is illegal in France so that was not the cause. There was water in the fuel though. I keep a litre bottle of fuel aside as it makes bleeding the engine easier and that too becomes discoloured after a year or more so I reckon that diesel really doesn`t keep very well at all. Incidentally I never fill the tank before winter - the tank is huge and I`m not scrapping 1,000 euros worth of fuel, anyway in a virtually sealed tank where is the condensation going to come from?. I think small, separate stainless tanks might be the way forward

 

Sorry Bee, the smell is because the sulphur has been removed from the fuel, so it no longer smells like diesel of years gone by. I found out when I contacted trading standards about a fill of road fuel that did not sell like diesel - I thought the garage had been supplying white spirit. Since then, we have the added FAME that also presumably alters the smell. I suspect the colour change is the breakdown of FAME over time.

[Alan de Enfield]

Sticky Diesel has been a huge problem in the agricultural businesses and has been investigated in depth and many articles in Farmers Weekly

 

Over the last few years I have posted some of these, but was informed that "thats a totally different market and doesn't apply to canal boats", then there was also the case of FAME diesel eating the rubber in pumps and pipes on agricultural machinery stood over Winter.

 

 

2020 :

 

https://www.fwi.co.uk/machinery/farm-maintenance/machinery-maintenance/red-diesel-the-problems-uncovered

 

Fast forward to December 2023 :

 

 

Sticky Diesel - Fact or Fiction?

 

Sticky diesel is causing multiple fuel problems on the UK inland waterways

 

Posted on December 4, 2023 by News Hound

 

 

 

A massive increase in diesel fuel related breakdowns have been due to sticky diesel.

 

Article by Darrell Broscomb, Marine Engineer at Tooley’s boatyard in Banbury.

 

Darren writes that he sees many different mechanical issues throughout the year, but during 2023 notes seeing a massive increase in diesel fuel related breakdowns due to sticky diesel.  At present, the marina had four boats requiring attention because of fuel issues. Diagnosed as not just ‘diesel bug’ but something else entirely.  With this particular sticky diesel scenario, the fuel goes dark, smells different and leaves sticky tar-like deposits in the fuel system.

 

These issues have been quite challenging to diagnose as the symptoms vary hugely.  Some engines have plumes of white smoke, others vibrate terribly, and others stop running entirely for no apparent reason.

 

After replacing fuel filters and lift pumps, servicing diesel injectors, and even having injection pumps serviced, the problem can return within a few weeks.  This is very expensive for customers, and us too, as you can’t charge if you’ve been unable to fix anything.

 

On one boat that had had all of the above done, I bit the bullet and said, ‘Right, let’s get rid of the fuel, clean the tank and replace it with fresh diesel.’  Well, it only worked!  The boat was fixed, and we had a very pleased customer.

 

So, what exactly is going on then?  We’re fortunate to live in the age of Google, and online searches brought up many articles with similar problems experienced around the country; farmers have been having issues with sticky diesel for a few years now.

 

Diesel fuel just isn’t keeping well it seems. This is partly because it now has a percentage of biofuel; FAME (fatty acid methyl ester), and the problems seem to be caused by this ‘going off’ in the fuel.

 

Refineries think that the majority of fuel is used within 18 -24 days of leaving the refinery and state that fuel will perform satisfactorily for 4 to 6 months with the preservatives they use. Unfortunately, this isn’t much help to someone who uses their pleasure craft two or three times a year.  Their fuel could be well over a year old before it is used.

 

On top of this, modern diesel engines also circulate the fuel through the diesel system to keep components cool and lubricated; the fuel gets heated and cooled during this process and may pass through the system many times before actually being combusted in the engine.  This process changes the structure of the diesel and sees an increase in contaminants in it.  These modern engine fuel systems have very fine tolerances, and the fine injector nozzles can block up.

 

There has been some research done by Fuel Additive Science Technology (FAST) – which produces Exocet additives. This research has shown that the sticky diesel issue has nothing to do with water, rust or poor storage like the causes of diesel bug; the samples they tested have all had a high particle content. Particles of interest found are sterol glucosides and monoglycerides, and it is these which are causing the sticky deposits; they come from biodiesel, and cold weather separates them from the fuel.

 

Looking forward, what can we do?

 

Storage

 

For a long time, it has been good advice to keep diesel tanks filled to prevent condensation from contaminating the fuel with water.  I’m not sure if this is a good idea anymore unless you use a lot of diesel and will use your fuel in under 6 months. So, ideally, only purchase what you plan to use annually and replace unused fuel before the next season.  Smaller, stainless steel cylindrical storage tanks with bottom drains would be ideal, please boatbuilders.

 

Treatment

 

Fuel degrades quickly, so an additive is a good idea; it should include a stabiliser, cetane improver, demulsifier, detergent and a biocide to arrest microbial contamination.  Fuel polishing is a good idea; it seems that fuels with a higher particular content are causing the problems, so polishing (filtering) down to 2 microns could be a suitable treatment.  Fuel polishing is available at many boatyards, or if you are inventive, the parts are readily available to build your own polishing system.

 

In conclusion, diesel isn’t what it used to be, and without preventative measures, it is unreasonable to expect it to maintain its quality.  Studies have shown that fuel will start degrading within 28 days.

 

Useful links about the causes of sticky diesel:

 

How Healthy is your Stored Diesel?

 

Curious cases of sticky fuel

 

Red diesel: The problems uncovered

 

Sticky Diesel – YouTube video

 

 

 

 

Edited July 28 by Alan de Enfield

[Bargebuilder]

2 hours ago, Alan de Enfield said:

modern diesel engines also circulate the fuel through the diesel system to keep components cool and lubricated; the fuel gets heated and cooled during this process and may pass through the system many times

This could be used to advantage by adding more and better filtration at the point of take off. All fuel sucked from the tank could effectively be polished and a proportion of this polished fuel would be circulated back to the tank, gradually cleaning the contents. Even better if the fuel take off is from a fuel sump at the lowest point of the tank.

[peterboat]

8 hours ago, Alan de Enfield said:

Sticky Diesel has been a huge problem in the agricultural businesses and has been investigated in depth and many articles in Farmers Weekly

 

Over the last few years I have posted some of these, but was informed that "thats a totally different market and doesn't apply to canal boats", then there was also the case of FAME diesel eating the rubber in pumps and pipes on agricultural machinery stood over Winter.

 

 

2020 :

 

https://www.fwi.co.uk/machinery/farm-maintenance/machinery-maintenance/red-diesel-the-problems-uncovered

 

Fast forward to December 2023 :

 

 

Sticky Diesel - Fact or Fiction?

 

Sticky diesel is causing multiple fuel problems on the UK inland waterways

 

Posted on December 4, 2023 by News Hound

 

 

 

A massive increase in diesel fuel related breakdowns have been due to sticky diesel.

 

Article by Darrell Broscomb, Marine Engineer at Tooley’s boatyard in Banbury.

 

Darren writes that he sees many different mechanical issues throughout the year, but during 2023 notes seeing a massive increase in diesel fuel related breakdowns due to sticky diesel.  At present, the marina had four boats requiring attention because of fuel issues. Diagnosed as not just ‘diesel bug’ but something else entirely.  With this particular sticky diesel scenario, the fuel goes dark, smells different and leaves sticky tar-like deposits in the fuel system.

 

These issues have been quite challenging to diagnose as the symptoms vary hugely.  Some engines have plumes of white smoke, others vibrate terribly, and others stop running entirely for no apparent reason.

 

After replacing fuel filters and lift pumps, servicing diesel injectors, and even having injection pumps serviced, the problem can return within a few weeks.  This is very expensive for customers, and us too, as you can’t charge if you’ve been unable to fix anything.

 

On one boat that had had all of the above done, I bit the bullet and said, ‘Right, let’s get rid of the fuel, clean the tank and replace it with fresh diesel.’  Well, it only worked!  The boat was fixed, and we had a very pleased customer.

 

So, what exactly is going on then?  We’re fortunate to live in the age of Google, and online searches brought up many articles with similar problems experienced around the country; farmers have been having issues with sticky diesel for a few years now.

 

Diesel fuel just isn’t keeping well it seems. This is partly because it now has a percentage of biofuel; FAME (fatty acid methyl ester), and the problems seem to be caused by this ‘going off’ in the fuel.

 

Refineries think that the majority of fuel is used within 18 -24 days of leaving the refinery and state that fuel will perform satisfactorily for 4 to 6 months with the preservatives they use. Unfortunately, this isn’t much help to someone who uses their pleasure craft two or three times a year.  Their fuel could be well over a year old before it is used.

 

On top of this, modern diesel engines also circulate the fuel through the diesel system to keep components cool and lubricated; the fuel gets heated and cooled during this process and may pass through the system many times before actually being combusted in the engine.  This process changes the structure of the diesel and sees an increase in contaminants in it.  These modern engine fuel systems have very fine tolerances, and the fine injector nozzles can block up.

 

There has been some research done by Fuel Additive Science Technology (FAST) – which produces Exocet additives. This research has shown that the sticky diesel issue has nothing to do with water, rust or poor storage like the causes of diesel bug; the samples they tested have all had a high particle content. Particles of interest found are sterol glucosides and monoglycerides, and it is these which are causing the sticky deposits; they come from biodiesel, and cold weather separates them from the fuel.

 

Looking forward, what can we do?

 

Storage

 

For a long time, it has been good advice to keep diesel tanks filled to prevent condensation from contaminating the fuel with water.  I’m not sure if this is a good idea anymore unless you use a lot of diesel and will use your fuel in under 6 months. So, ideally, only purchase what you plan to use annually and replace unused fuel before the next season.  Smaller, stainless steel cylindrical storage tanks with bottom drains would be ideal, please boatbuilders.

 

Treatment

 

Fuel degrades quickly, so an additive is a good idea; it should include a stabiliser, cetane improver, demulsifier, detergent and a biocide to arrest microbial contamination.  Fuel polishing is a good idea; it seems that fuels with a higher particular content are causing the problems, so polishing (filtering) down to 2 microns could be a suitable treatment.  Fuel polishing is available at many boatyards, or if you are inventive, the parts are readily available to build your own polishing system.

 

In conclusion, diesel isn’t what it used to be, and without preventative measures, it is unreasonable to expect it to maintain its quality.  Studies have shown that fuel will start degrading within 28 days.

 

Useful links about the causes of sticky diesel:

 

How Healthy is your Stored Diesel?

 

Curious cases of sticky fuel

 

Red diesel: The problems uncovered

 

Sticky Diesel – YouTube video

 

 

 

 

Unfortunately I am now back to a diesel boat and worse its a sea boat so before I go to sea it will be clean fuel for it. I do have a diesel heater so using it ensures a turnover of it. Also we use it to go up and down the Beck and river regularly to keep using it. I have to say when I had sticky diesel it was sticky to the touch and smelled strange. I have just remembered I have 25 litres of it in a can to be used in the diesel stove

Edited July 28 by peterboat