Diesel Bug Chapter 2; am I just wasting my time?

[BobnLesley]

Following on from last week's post I opened our tank's inspection plate and using a Pela type pump and lots of industrial alcohol I drained and flushed several times the tank to the best of our abilities. Sadly the tank's inspection opening only allows me to reach half the tank due to a baffle plate - I could and did get the pela-pump's pipe beyond - and the inaccesible half is the low point; even transfering 100+kg from stern to bow, plus getting three people to stand on the bow's not sufficient to fully counteract that; poor installation, but hey, Greek engineers installed it so what else would I expect?
So, the tank's clean other than the bit that won't come, hopefully just a pint or two, but that's really just a guess, poured in 6 -gallon of clean diesel and a serious dollop of biocide, then bled the system and re-started. It ran at tickover/moderate revs for an hour hour then stopped. The following morning I changed the filters, re-started and got almost two hours out of it; yesterday I did nothing and today with new filters I'm up to 2.5 hours and still going.
Getting the tank out will be a b*****d of a job, at best I suspect that I'll need to haul out and remove the engine-inlet seacock; but will the current policy actually clear it eventually? I've got a week to sit and let it run and a big box of Delphi primary filters to provide replacements, though perhaps not as many Yanmar secondary/fine filters (today it's running on the old one). Can I realistically expect it to clear eventually, or am I just going to have a repeat performance in another two or three days/weeks/months?

 

[sarabande]

You can set yourself up a fuel polishing rig for about 40 squids.

A 12v Fuel pump, a relatively cheap filter unit, and some pipe.

There are instructions on the forum

http://www.ybw.com/forums/search.php?searchid=7855172

Set up the pump to remove and replenish for a couple of hours, and keep rocking the boat.

Once it is known you have a fuel polisher, it is a good bargaining means for beer tokens.

 

[Caer Urfa]

Hi Bob

When you get a real bad dose of diesel bug you will get loads of advice recommending various products but the sad news is the tanks either needs to come out or you need to
get full access to clean it all out properly.

Also just as important don't forget to check/clean all the fuel pipework

If you don't you will be buying filters like no tomorrow and do you really want to be 5 miles offshore wondering if your diesel is clean enough

I had the same problems years ago and spent month's trying to cure it, no it's not easy and yes it costs and yes it's messy but do the job right and sleep at night

 

[Topcat47]

The short answer is "NO". The problem with the bug is the gelatinous crap it leaves behind. I put in an additional hatch to get at the lowest part of my tank. It's proved itself twice since doing it. Every time I've had the bug, I've removed all traces of the black jelly from the tank, then wiped the surfaces with an antibiotic cleaner. Top up with new fuel + Biocide, there will still be traces of the bug in the fuel lines. Change all the filters then run the engine. With no black crud in the tanks and the fuel dosed with biocide, any lurking in the pipework will be killed when the overspill is put back in the tank. If you can plumb the depths of the tank with a pela, you can remove water which collects there. The bug lives in the fuel/water interface.

If you don't get to the deepest part of the tank, you can't eradicate the problem.

By the way, if you have a strainer on your pick-up, it will become blocked by the jelly and you have to clean that, too

 

[peteK]

It may eventually clear as the diesel goes through the filter and is returned too the tank,have problems myself at the moment with water in the fuel,draining the tank and going to remove it for cleaning.

 

[superheat6k]

I think you will get on top of it, but only if you persevere. Try to get as much loose liquid out from the inaccessible section as possible - can you cut a hole in the baffle via the access hole to improve access for a suction tube ?

I would use a shock doss of Grotamar, Marine 16 or Soltron, then dose heavily with Fuel set, which actually converts small amounts of water into burnable product. Once the fuel is dry the bug growth will cease, so you then just have to deal with the residue, and most importantly stop further water getting in. There are two very likely sources - filler cap seal and poor quality of bunkered fuel. I have heard tales of fuel getting in around the fuel cap fitting, then entering through a loose hose to inner fitting joint, so do not rule this out. Also if water puddles over and around the fuel filler cap try to modify it to prevent this - e.g. make a small moulding to lift the filler fitting above the puddle.

Replace the sealing O ring and smother the filler cap threads with waterproof grease, e.g. seacock grease. Ok it is messy when you come to refuel, so what - 2 minutes to clean your hands is a minor inconvenience. As Sarabande suggests put yourself a simple polishing rig together and start using it. I use mine once a month for about an hour each side, and after every re-fuel. I have been using this since 2008 and have not had any contaminated fuel issues since.

I get very little crud / water out, and if I suddenly get a mass surge after a refuel I know precisely where it will have come from.

 

[NormanS]

The real answer rests with the builders. Personally I think it's irresponsible to install tanks without a means of draining the lowest point. This can ideally be a dirt sump with a drain, or failing that where that is impracticable, at least an extraction pipe led to the lowest point. Sorry, this doesn't help the OP, but boat buyers - it's the kind of detail to look out for.

 

[lw395]

You can set yourself up a fuel polishing rig for about 40 squids.

A 12v Fuel pump, a relatively cheap filter unit, and some pipe.

There are instructions on the forum

http://www.ybw.com/forums/search.php?searchid=7855172

Set up the pump to remove and replenish for a couple of hours, and keep rocking the boat.

Once it is known you have a fuel polisher, it is a good bargaining means for beer tokens.

In my experience, polishing is the way to go.
I knocked up a polishing rig with a mate, using mostly bits we could find.
We play around with it, but currently we have 3 stages of filters.
Firstly a cheap cleanable re-useable filter intended for oil central heating
Secondly a CAV filter with glass bowl
thirdly an inline fuel filter intended for a car.

Then the fuel goes to the pump which is a 12V facet knock-off from ebay.
This works well for us. A refinement would be if the first filter could handle more gunk before clogging.

Our other contribution is 'the agitator'.
It's a bit of old rope mounted on the end of a length of plastic plumbing pipe.
We stuff it into the tank and use it to flail the crud off the tank floor and walls. We spin it with a cordless drill. It will go down the filler hose if needs be.

 

[[70521]]

The real answer rests with the builders. Personally I think it's irresponsible to install tanks without a means of draining the lowest point. This can ideally be a dirt sump with a drain, or failing that where that is impracticable, at least an extraction pipe led to the lowest point. Sorry, this doesn't help the OP, but boat buyers - it's the kind of detail to look out for.

The fuel bug is a "recent" problem. You cannot design in a solution to a problem you don't know exists.

I am currently working on cleaning my tank, replacing all the fuel lines in order to sort the problem I have with the bug. Thankfully the tank is easy to remove. I've totally re-thunk fuel management on the boat and am moving from red to white, only putting in the tank what I use and will empty the tank when the boat goes ashore in future as the manufacturers are now publicly stating that modern diesel has a shelf life of six months.

 

[NormanS]

The fuel bug is a "recent" problem. You cannot design in a solution to a problem you don't know exists.

I am currently working on cleaning my tank, replacing all the fuel lines in order to sort the problem I have with the bug. Thankfully the tank is easy to remove. I've totally re-thunk fuel management on the boat and am moving from red to white, only putting in the tank what I use and will empty the tank when the boat goes ashore in future as the manufacturers are now publicly stating that modern diesel has a shelf life of six months.

You have a solution which works for you. Good, that's fine - well done.

The fuel "bug" may be a recent problem, but the presence of water in the bottom of tanks, is certainly not a new thing.

An engine will stop when either water or "bug" interferes with its fuel supply.

I think I would be correct in saying that when yachts had deep bilges, and it was therefore feasible for their tanks to have drains, they were so equipped. Now with many more flat bottomed boats, where the provision of a drain is not easy, I am suggesting that tanks should have a pipe led to their lowest point.

 

[Plum]

Following on from last week's post I opened our tank's inspection plate and using a Pela type pump and lots of industrial alcohol I drained and flushed several times the tank to the best of our abilities. Sadly the tank's inspection opening only allows me to reach half the tank due to a baffle plate - I could and did get the pela-pump's pipe beyond - and the inaccesible half is the low point; even transfering 100+kg from stern to bow, plus getting three people to stand on the bow's not sufficient to fully counteract that; poor installation, but hey, Greek engineers installed it so what else would I expect?
So, the tank's clean other than the bit that won't come, hopefully just a pint or two, but that's really just a guess, poured in 6 -gallon of clean diesel and a serious dollop of biocide, then bled the system and re-started. It ran at tickover/moderate revs for an hour hour then stopped. The following morning I changed the filters, re-started and got almost two hours out of it; yesterday I did nothing and today with new filters I'm up to 2.5 hours and still going.
Getting the tank out will be a b*****d of a job, at best I suspect that I'll need to haul out and remove the engine-inlet seacock; but will the current policy actually clear it eventually? I've got a week to sit and let it run and a big box of Delphi primary filters to provide replacements, though perhaps not as many Yanmar secondary/fine filters (today it's running on the old one). Can I realistically expect it to clear eventually, or am I just going to have a repeat performance in another two or three days/weeks/months?

If your pickup pipe is lower than the level level of the diesel in the tank after you have extracted what you can reach ghrough the inspection plate, why not suck from the pickup pipe by connecting it to your pella? That will save you some filters at least.

Www.solocoastalsailing.co.uk

 

[lw395]

The fuel bug is a "recent" problem. You cannot design in a solution to a problem you don't know exists.

I am currently working on cleaning my tank, replacing all the fuel lines in order to sort the problem I have with the bug. Thankfully the tank is easy to remove. I've totally re-thunk fuel management on the boat and am moving from red to white, only putting in the tank what I use and will empty the tank when the boat goes ashore in future as the manufacturers are now publicly stating that modern diesel has a shelf life of six months.

I had my first diesel bug in 2002.

As an aside, I've just booked my car in for an MoT, and while they've got it, they will do the fuel filter for me.
The filter is smaller than a coke can and I've not changed it in 36,000 miles or 3 years. That must be between 3 and 4 thousand litres of disease-all through it.
So if road diesel was 1 part in 10,000 crud, I would be in deep trouble.
Food for thought.
Food for amoeba, funghi and god knows what else more like?

We are still happily using red diesel, but we don't aim to store it longer than necessary. We fill up before a cruise.
We polish the tank about twcie a season and don't find much dirt.
But we are not exactly in a Panama climate to be fair.
As I see it, it's still all about water in the tank. But once the beasties start digesting your fuel, they produce more water.

 

[Quandary]

I used to have contamination problems on our Sigma which had the fuel filler flush on the deck just beside the toe rail with any rain or sea water flowing right over it. When we eventually got the tank cleaned, ( it came out of the aft cabin but not through the hatch) I raised the filler about 5mm. with a bed of filler under it , enough to at least get it above the rain. I then changed the filler cap washer at least once a year, keeping spares on board. In addition every time I filled I taped over the cap with duck tape, replacing it each time the cap was unscrewed. Since then I have always used Soltron in preference to the biocides, based on advice from the Engineering Dept.of QUB who did some work in this field at the time, when they were not busy building road racing two stroke bikes, Ray McCullough was their lab technician as well as the rider.

 

[CAPTAIN FANTASTIC]

If you have diesel bug, you will need to siphon/pump out the bottom of the tank, as it is heavier and it sinks to the bottom; its black in colour and feels like tar. It doesn't normally block pipes, it blocks terminal points such as filters. Moisture encourages bug growth; petrol kills the microbial that causes the contamination; I can not prevent moisture but I put approx 1% of petrol in my tanks and have no problem with microbial growth.

 

[BobnLesley]

The engine's run for 3.5 hours at which point I turned it off myself - a pleasant novelty after almost a week of forced shut-downs!

I have a 12v inline pump and some spare hose so if I can get a suitable filter unit here, I'll and circulate the fuel tank through that as well as/instead of via the engine, I should be able to feed it through to a pick-up location much nearer to the tank's low point that way too.

 

[Skylark]

You can set yourself up a fuel polishing rig for about 40 squids.

A 12v Fuel pump, a relatively cheap filter unit, and some pipe.

There are instructions on the forum

http://www.ybw.com/forums/search.php?searchid=7855172

Set up the pump to remove and replenish for a couple of hours, and keep rocking the boat.

Once it is known you have a fuel polisher, it is a good bargaining means for beer tokens.

The link doesn't work (Windows and iPhone), could I trouble you to point me in the right direction, please?

I have no immediate need but making one of these does seem to be an excellent winter project.

 

[[70521]]

I used to have contamination problems on our Sigma which had the fuel filler flush on the deck just beside the toe rail with any rain or sea water flowing right over it. When we eventually got the tank cleaned, ( it came out of the aft cabin but not through the hatch) I raised the filler about 5mm. with a bed of filler under it , enough to at least get it above the rain. I then changed the filler cap washer at least once a year, keeping spares on board. In addition every time I filled I taped over the cap with duck tape, replacing it each time the cap was unscrewed. Since then I have always used Soltron in preference to the biocides, based on advice from the Engineering Dept.of QUB who did some work in this field at the time, when they were not busy building road racing two stroke bikes, Ray McCullough was their lab technician as well as the rider.

Interesting thoughts about the location of the filler, why they were ever placed at deck level is beyond me, and am looking to move mine at some point in the future - there is space and access to the transom.

 

[SteveGorst]

You can set yourself up a fuel polishing rig for about 40 squids.

A 12v Fuel pump, a relatively cheap filter unit, and some pipe.

There are instructions on the forum

http://www.ybw.com/forums/search.php?searchid=7855172

Set up the pump to remove and replenish for a couple of hours, and keep rocking the boat.

Once it is known you have a fuel polisher, it is a good bargaining means for beer tokens.

I've just cleaned out my tank, luckily it had a nice large hatch and it was relatively easy to get into. On the bottom of the tank was loads of said black goo although the diesel itself was clean. The idea of a diesel polisher makes sense but I am very sceptical that it would have lifted all the goo from the bottom of my tank as it was stuck to the bottom of the tank. I had previously tried sucking up diesel from the bottom of my tank with a heavy duty Pela and there was no sign of bug but as the filter continued to block every 20 hours or so I eventually bit the bullet and emptied the tank and there it was.

 

[pvb]

The engine's run for 3.5 hours at which point I turned it off myself - a pleasant novelty after almost a week of forced shut-downs!

I have a 12v inline pump and some spare hose so if I can get a suitable filter unit here, I'll and circulate the fuel tank through that as well as/instead of via the engine, I should be able to feed it through to a pick-up location much nearer to the tank's low point that way too.

Wow, 3.5 hours, you're getting there! When I got diesel bug in the keel tank of my old HR, I had the same problem as you, limited access due to baffles. I rigged up a simple fuel polishing rig with an old water pump and a CAV filter, and had a rigid pipe to suck the fuel up, plus another rigid pipe with a right-angle bend on the end to squirt the returned fuel into the dark recesses beyond the baffle. Long, boring job, but it worked.

 

[chrishscorp]

Cleaned my tank last year, only access was the filler tube and the fuel drain off 8mm diameter and she is on a swinging mooring.
I used one of those magic fuel funnels for putting the fuel back in, a length of microbore pipe connected to the dinghy foot pump to agitate and get to the corners, a stick in a cordless with some polypropylene frayed out on the end was also used to keep it agitated

Suctioned out from top down three quaters of the fuel then used the remaining to wash out circulate and agitate the grot, i had never had any bother with the fuel but was going cross channel for the first time so thought it may be prudent. i am glad i did the crud that came out was amazing. I kept a 2 lt bottle of the grot and after a month sat and left alone it had not cleared