diesel bug?

[A1Sailor]

NOTHING IN THE FILTER? I would suspect air, what pre filters do you have?

I got air in the filters. The crud was blocking the "uptake pipe" and the fuel lift pump was drawing air in via connections. It stopped when I tightened everything! So did the engine...
It ran very much better after I cleaned the tank!:encouragement:

 

[Elessar]

Helpful and depressing A1!

It feels like that is the problem.

It’s the port tank and both fillers are to starboard so I can’t even get a pela tube in that tank and I certainly can’t see in there.

Will polishing desolve and remove crap like that? I’m suspecting not.

If not I will have to cut inspection hatches in the tanks.

How do you cut swarf free or do I just rely on the filters and not worry?

 

[Greg2]

I am reading this with interests. Virtually all of our boats have had black bits accumulate in the pre-filters over the course of a season but never to the extent that it caused a problem. A flush through of the pre-filters each winter seems to keep on top of things.

On our last boat it was a bit worse than others so I made up a fuel polishing system using a 12v pump, a filter housing for a domestic oil tank and some pipe work. Having let the tanks run down to about half I ran the fuel though the system several times and got a lot of crud out but I didn’t go as far as cutting holes and trying to clean inside the tanks, mainly because it was a Broom and the tanks were made of kryptonite or some similarly robust metal! I spoke to a professional fuel polishing outfit before deciding to have a go myself and the weren’t keen to try cutting into the Broom tanks due to previous experience.

The current boat has quite a bit of crud that gathered in the pre-filters in the short space of time that we used it having purchased at the end of last season so I think another fuel polishing event is on the cards. Might go with a professional outfit this time.

 

[kashurst]

Helpful and depressing A1!

It feels like that is the problem.

It’s the port tank and both fillers are to starboard so I can’t even get a pela tube in that tank and I certainly can’t see in there.

Will polishing desolve and remove crap like that? I’m suspecting not.

If not I will have to cut inspection hatches in the tanks.

How do you cut swarf free or do I just rely on the filters and not worry?

from memory on my 410, on the port side is a two seat sofa that pulls out. under that is a pull up piece of flooring, under that is the tank and fuel sender - is your boat the same?

 

[Hurricane]

Mark
Do you use any additive?

I didn't until it was too late and we had the bug (noticed 100 miles from land!!)
We hobbled home - using spare filters etc.
The tanks were about one third full.
To rectify the problem, we attached hoses to the drain points at the bottom of the tanks.
Then drew off all the sludge - it collects where there is water (at the bottom of the tanks).
After about 25 litres (on each tank) the fuel started to run clearer.
We filled a spare container with the clearer fuel and added a large dose of Marine 16 (enough to shock the rest of the fuel in the tanks).
We then poured the heavily concentrated fuel/Marine 16 into the tanks through the inspection hatches in the tanks.
Then we connected a small pump to the hose that was attached to the bottom of the tanks and, using a "home made" nozzle, we circulated/sprayed the fuel around the tanks by leaning into the tank hatches.
We left the pump/spray running for a few hours in an attempt to get the Marine 16 thoroughly distributed into the remaining fuel.

The idea was to use the fuel left in the tanks to kill the bug with a heavy dose of Marine 16.

I did buy a spare Racor filter assembly with the idea of creating a home made fuel polisher but, in fact, it wasn't necessary - the Marine 16 did the job.

A few points here.
AFAIK there are two ways to manage diesel bug.
1 - to avoid it in the first place using a treatment that dissolves/emulsifies any water into the fuel so that it will pass through the engine - fuel bug needs water to grow. I believe that Fuelset is one such product.
2 - simply kill any bug present - using something like Marine 16 which I consider to be a herbicide - a "kind of" weed killer.

I chose the Marine 16 route because we already had the bug - Using an emulsifier would have been like "closing the door after the horse had bolted".

During this process, I ran a test.
I filled a container (about 15 litres) of the black sludge that initially came from the bottom of the tank and added small amount of Marine 16 - then left it overnight.
The following morning the black sludge had gone.
This was enough proof to me that the Marine 16 approach works.
So we finished the job by cleaning the fuel lines and filter assemblies using a strong fuel/Marine 16 solution.

I NOW TREAT ALL MY FUEL DELIVERIES WITH MARINE 16

It isn't expensive - a no brainer - to everyone - just do it.

BTW Grotamar is a similar product to Marine 16 but more expensive.

 

[Elessar]

from memory on my 410, on the port side is a two seat sofa that pulls out. under that is a pull up piece of flooring, under that is the tank and fuel sender - is your boat the same?

No it’s a sideboard. Chair / chart table forward of that.

You make a good point that if I can find the sender, I can gain access. Job for the weekend.

 

[Elessar]

Mark
Do you use any additive?

I didn't until it was too late and we had the bug (noticed 100 miles from land!!)
We hobbled home - using spare filters etc.
The tanks were about one third full.
To rectify the problem, we attached hoses to the drain points at the bottom of the tanks.
Then drew off all the sludge - it collects where there is water (at the bottom of the tanks).
After about 25 litres (on each tank) the fuel started to run clearer.
We filled a spare container with the clearer fuel and added a large dose of Marine 16 (enough to shock the rest of the fuel in the tanks).
We then poured the heavily concentrated fuel/Marine 16 into the tanks through the inspection hatches in the tanks.
Then we connected a small pump to the hose that was attached to the bottom of the tanks and, using a "home made" nozzle, we circulated/sprayed the fuel around the tanks by leaning into the tank hatches.
We left the pump/spray running for a few hours in an attempt to get the Marine 16 thoroughly distributed into the remaining fuel.

The idea was to use the fuel left in the tanks to kill the bug with a heavy dose of Marine 16.

I did buy a spare Racor filter assembly with the idea of creating a home made fuel polisher but, in fact, it wasn't necessary - the Marine 16 did the job.

A few points here.
AFAIK there are two ways to manage diesel bug.
1 - to avoid it in the first place using a treatment that dissolves/emulsifies any water into the fuel so that it will pass through the engine - fuel bug needs water to grow. I believe that Fuelset is one such product.
2 - simply kill any bug present - using something like Marine 16 which I consider to be a herbicide - a "kind of" weed killer.

I chose the Marine 16 route because we already had the bug - Using an emulsifier would have been like "closing the door after the horse had bolted".

During this process, I ran a test.
I filled a container (about 15 litres) of the black sludge that initially came from the bottom of the tank and added small amount of Marine 16 - then left it overnight.
The following morning the black sludge had gone.
This was enough proof to me that the Marine 16 approach works.
So we finished the job by cleaning the fuel lines and filter assemblies using a strong fuel/Marine 16 solution.

I NOW TREAT ALL MY FUEL DELIVERIES WITH MARINE 16

It isn't expensive - a no brainer - to everyone - just do it.

BTW Grotamar is a similar product to Marine 16 but more expensive.

Thanks Mike, it is encouraging that a shock dose will resolve crap that’s in there already.
I did have marine 16 in there but not routinely, just post problem. Maybe it wasn’t enough of a dose.

Sadly there are no outlets at the bottom of my tanks. All at the top.

Ps visiting st c in a couple of weeks if you’re about.

 

[Hurricane]

Ps visiting st c in a couple of weeks if you’re about.

Out late on the 16th May for a week - will you be there?

 

[Elessar]

Out late on the 16th May for a week - will you be there?

Yep for the weekend.

 

[A1Sailor]

Helpful and depressing A1!

It feels like that is the problem.

It’s the port tank and both fillers are to starboard so I can’t even get a pela tube in that tank and I certainly can’t see in there.

Will polishing desolve and remove crap like that? I’m suspecting not.

If not I will have to cut inspection hatches in the tanks.

How do you cut swarf free or do I just rely on the filters and not worry?

Pete/prv is the forum expert.:encouragement:

I've done exactly this.

No manufacturer involved; I just went to Metal Supermarkets and got them to cut me two rectangles of stainless sheet about an inch bigger in all directions than my intended hole. In the shed at home I then cut out the middle of one of the sheets to make a square ring. I clamped the two together and drilled a series of holes around the edge, correctly sized for the thread I intended to use. Then I tapped all the holes in the ring plate, and widened the holes in the cover plate to 1mm larger than the intended studs (to allow for slight misalignment in fitting). I screwed machine screws into all the tapped holes, then tack-welded the heads to ensure they stayed in place (loctite, some kind of adhesive, or just doing them up very tight and galling the threads would probably do just as well if you don't have a welder). So I then had a square ring with protruding studs, and a cover plate with holes to match. I also made up a gasket out of nitrile sheet from eBay, using the cover plate as a template.

I tried several ways of cutting the tank - metal-cutting blades for a jigsaw went blunt after about half an inch of cut each, and the tip of the cheap nibbler broke off. So it had to be the angle grinder, which worked well. I started by pumping out all of the diesel through the sender hole, then tipped in plenty of soapy water to emulsify the dregs. I also hung wet cloths around the compartment to catch the sparks from the grinder, put on a damp cotton jacket and hat, and had a 10l foam extinguisher to hand. The actual cutting went very easily, along a line marked out using the stud plate as a template.

After filing down the edges of the hole slightly, I used the cover plate as a template to drill the bolt holes. The ring then went in through the opening and the studs passed up through the holes. The nitrile gasket placed over the top grips the studs (its holes are slightly undersize) and stops the plate falling down into the tank. So after vigorously cleaning the tank with a scrubbing brush and Scotchbrite, pumping out the soapy water, and thoroughly drying it with kitchen roll, I could then put the cover plate over the studs and do up the nuts.

Pete

 

[Restoration man]

Hi mark, could you take the fuel level gauge out and pump the old fuel from there ???in our sealine 360 there quite easy to get at , and then polish it etc ???? I’ve also heard that petrol kills diesel bug not sure if this is true , maybe drain tank and put petrol in there leave to help soften and crap on bottom of tank then re flush a few times , and take the pipe off the filter and attach your dingy pump to and reverse flush the stand pipe in the tank ,
Nick “Bojangles”

 

[simonfraser]

Hi mark, could you take the fuel level gauge out and pump the old fuel from there ???in our sealine 360 there quite easy to get at , and then polish it etc ???? I’ve also heard that petrol kills diesel bug not sure if this is true , maybe drain tank and put petrol in there leave to help soften and crap on bottom of tank then re flush a few times , and take the pipe off the filter and attach your dingy pump to and reverse flush the stand pipe in the tank ,
Nick “Bojangles”

yes that would give you access for a hose. getting the fuel level sensor back on without leaks takes a lot of patience.

 

[Elessar]

Ok update on this.

I have dismantled and cleaned the filters.

I have shock dosed the tanks.

The port side pipe between the tank and the filter is still blocked.

So I made up a line that I can connect a bike pump to to push the contaminated fuel back into the tank.

I am up to 100 psi and it won’t budge.

I disconnected the pump and 100psi fuel sprayed me and the engine room.

I’ve pumped it back up to 100psi and will leave it overnight. I hope it will have a big fart eventually.

If anyone has any other bright ideas I’d love to hear them. Getting to the bit of the tank where the pipe comes out will cause a cut in finished wood.

I’ve cut under a drawer and can get to the sender now.

I will read any suggestions after my shower........

 

[superheat6k]

Can you cut into the pipe closer to the tank where you can later fit a straight coupler ? Then perhaps try feeding some stiff Monel wire, or if the internal diameter is large enough perhaps some galvanised running rigging wire, into the pipe and through the blockage.

 

[Elessar]

Can you cut into the pipe closer to the tank where you can later fit a straight coupler ? Then perhaps try feeding some stiff Monel wire, or if the internal diameter is large enough perhaps some galvanised running rigging wire, into the pipe and through the blockage.

Yes. That’s possible. Not easy but possible. Good idea - thanks!

 

[burgundyben]

If 100 psi didnt blow it out I'd be looking for something other than fuel bug blockage.

 

[Keith-i]

This was the dip tube in my tank.



Made of copper and furred up with a black substance, possibly dead bug. It was partially blocking the tube and bits would ocassionally break free and get deposited in the glass bowl of the Separ filter. I replaced it with a steel dip tube and keep the tank dosed with Grotomar 82. I gather copper is not great long term with diesel and bug - you can see the pitting in the photo below. Strangely there wasn't much grime in the tank other than a 5ml medicine spoon and some kind of soft ball thing!

 

[Elessar]

This was the dip tube in my tank.

View attachment 77803

Made of copper and furred up with a black substance, possibly dead bug. It was partially blocking the tube and bits would ocassionally break free and get deposited in the glass bowl of the Separ filter. I replaced it with a steel dip tube and keep the tank dosed with Grotomar 82. I gather copper is not great long term with diesel and bug - you can see the pitting in the photo below. Strangely there wasn't much grime in the tank other than a 5ml medicine spoon and some kind of soft ball thing!

View attachment 77804

View attachment 77805

View attachment 77806

Copper pipes in mine which is worrying

Good news is that it farted. Made a noise like thunder. Now a gentle press of the pump and I can hear the flow into the tank.
Phew.
The racor filter was leaking slightly at the middle joint under the pressure so I’ll replace that seal (did you know it’s the same seal as the lid so you get a new one with every cartridge? ) then clean the engine room.

 

[rafiki_]

Good result Mark, well done.

 

[Sojourn]

Use Chris Curtis Clean Diesel company he operates all over the south coast
He will suck out fuel, clean out tanks of any sludge