Is this diesel bug ?

[Bobbybass]

I know this subject has been covered before...but I was after 'opinions'

 

I have helped others eradicate diesel bug and its given the appearance of being slimey....jelly like.

Yesterday, I changed my fuel filters and the primary filter had what 'appeared' to be bloack soot on the top of it. There wasn't a scrap of anything in the sediment bowl.

I normally put a jar under it once the filter is removed and then open the stop-tap to check flow.

I did this, but there was no flow, just a drip.

 

Checking the tank, I found that the bottom of the tank is covered in a similar sooty dust, especially in the corners.

I have now filtered all the fuel out into containers through a 1 micron filter, and removed about a tea cup of this black sooty dust mainly from the bottom of the tank. Most of it was not larger than 2mm across.

It didn't look like what I had seen before ?

It's really more like soot, very black and dusty, but some of it did seem to 'clump' although not large.

 

I have always thoroughly dosed my diesel fills with the recommended level of Marine 16.

 

I pumped as much of this out as I could, treated the tank with the 'blitz' dose of Marine 16, and then put the fuel (now filtered and ruby red) back in the tank, also treated.

 

The 'dust' was not in the fuel, but sitting on the bottom of the tank and wasn't really slimey.

 

Does this sound like some version of diesel bug ?

Thanks.

 

[Tony Brooks]

No, I have seen many filters with a dusting of black dust across the top and when I sucked the bottom of my tank I also pulled up an amount of gritty, dusty black. I think it is the remains of mill scale and flux from the tank welding plus dust and dirt that has subsequently got into the tank.

 

If the bits feel a bit soft they may also be "rubber" granules from the flexible fuel lines deteriorating. Such lines should be changed an extended intervals.

[OldGoat]

I know this subject has been covered before...but I was after 'opinions'

 

I have helped others eradicate diesel bug and its given the appearance of being slimey....jelly like.

Yesterday, I changed my fuel filters and the primary filter had what 'appeared' to be bloack soot on the top of it. There wasn't a scrap of anything in the sediment bowl.

I normally put a jar under it once the filter is removed and then open the stop-tap to check flow.

I did this, but there was no flow, just a drip.

 

Checking the tank, I found that the bottom of the tank is covered in a similar sooty dust, especially in the corners.

I have now filtered all the fuel out into containers through a 1 micron filter, and removed about a tea cup of this black sooty dust mainly from the bottom of the tank. Most of it was not larger than 2mm across.

It didn't look like what I had seen before ?

It's really more like soot, very black and dusty, but some of it did seem to 'clump' although not large.

 

I have always thoroughly dosed my diesel fills with the recommended level of Marine 16.

 

I pumped as much of this out as I could, treated the tank with the 'blitz' dose of Marine 16, and then put the fuel (now filtered and ruby red) back in the tank, also treated.

 

The 'dust' was not in the fuel, but sitting on the bottom of the tank and wasn't really slimey.

 

Does this sound like some version of diesel bug ?

Thanks.

 

The above points in two directions!

 

One - sooty and dust implies dirt or broken mill scale

 

Two - blocked filter suggests The Bug or a very, very dirty fuel tank. If the latter how is it that it's not happened before; is it a new boat?

Could it be your last fuel purchase?

How often do you change your filter?

 

If it's spongy then likely to be the Bug

If granular and gritty then it's muck - if so, why is it being sucked up? most fuel intakes are 1/2" at least above the bottom of the tank.

 

As usual, more info is needed.

[Naughty Cal]

We get our diesel in clean deionised water containers. They were as you would expect spotless when we started using them. Now they have lots of black "flakes" in them. And we buy our diesel from a reputable source with a very high turn over. Diesel is dirty hence the need to filter it.

 

If your filters are dirty it shows that they are working!!

[PhilR]

Apologies for asking a question rather than answering Bobbybass's post, but I thought it better than starting a new related thread.

 

I have just drained off about 30 mililitres of fuel from the sedimenter and it was dark blue in colour, but with no crap, grit or sediment. I then drained off another 30 mililitres and it was the usual clear red colour.

 

Is this the first warning signs of diesel bug? and what is the current concencus regarding the best treatment/additive?

I have never used any fuel additives and it is over 10 years since I had problems with water in the tank.

 

Cheers

Phil

[Naughty Cal]

Could it just be fine crap in the bottom of the filter changing the colour of the diesel?

 

I would change the filter to be on the safe side.

[Bobbybass]

Hi.

 

The boat is 15 years old and I change both fuel filters every 500 hours.

It was gritty but there was a lot of it.

Usuallly..including last year...at the start of season...I 'suck' some fuel right off the bottom of the tank into a glass jar and exmine it. It has always been spotless. My sediment bowl has never had anything in it...dust grit or water.

When I fill with fuel, I usually pour a precise measured precaution dose of Marine 16 into the tank first.

 

The fuel above this layer was still clear and ruby coloured with nothing in it.

 

This time...when I sucked it out..I used a copper pipe connected to some transparent so that I could see what was coming up. The copper pipe internal diameter was about 6mm...and it didn't get blocked even with huge amounts of this black coming up.

When I have seen diesel bug before ....it would have soon blocked a 6mm pipe...is this so ..?

 

Thanks again.

[onionbargee]

Edited April 23, 2013 by onionbargee

[Bobbybass]

Excellent.....it doesn't look like that...

Thanks for posting this.

Your photo is similar to that which I found when helping a mate to pump and cure his bug.

 

Reason I posted...was in case I had some different form of 'bug'

My own 'Bobbybass mutation' bug.

 

I must have picked up some grotty fuel...possibly in Babury as I fuelled there several times last year.

 

Thanks again.

[Naughty Cal]

Hi.

 

The boat is 15 years old and I change both fuel filters every 500 hours.

It was gritty but there was a lot of it.

Usuallly..including last year...at the start of season...I 'suck' some fuel right off the bottom of the tank into a glass jar and exmine it. It has always been spotless. My sediment bowl has never had anything in it...dust grit or water.

When I fill with fuel, I usually pour a precise measured precaution dose of Marine 16 into the tank first.

 

The fuel above this layer was still clear and ruby coloured with nothing in it.

 

This time...when I sucked it out..I used a copper pipe connected to some transparent so that I could see what was coming up. The copper pipe internal diameter was about 6mm...and it didn't get blocked even with huge amounts of this black coming up.

When I have seen diesel bug before ....it would have soon blocked a 6mm pipe...is this so ..?

 

Thanks again.

We change our filters once a year which equates to somewhere between 200 and 300 hours of use depending on our cruising that year. The tank filter usually has some dirt in it but the engine filter is usually spotless. We would rather change them on a regular basis then be stuck in the middle of the Wash and find we have a blocked filter

[onionbargee]

i marine 16 all the fuel i use, now the bug is around, only need a tiny preventative dose of it, 10ml per 200L drum, costs nothing much. Cleaning out the entire fuel system is not fun.

[Naughty Cal]

We dont use any additive. We just use our fuel rather than storing it.