Fuel Treatment

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gregorymc

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Hi all, Just returned to Motor-boating after joining the Raggies for a couple of years.
I bought a 1995 Sealine Senator 270 which has been lightly used for the last few years.
Lightly used normally means very lightly maintained, so that's the assumption that im working on as I begin the winterisation process.
The Diesel tank has around 50/60lts in it at the minute and my first thought was, get rid of it, clean the tank and start afresh.
Access to the tank is only through the fuel sender slot which is much good for getting your arm in and giving it a good wipe.
Should I just add a treatment like Marine 16 now.( the boat is on the hard and stored for winter so won't be able to swirl it around to mix it).
Or should I leave it until the start of the season and carry plenty of filters.? Greg
 
I use Grotamar 82 which is formulated for biodiesel , I would get a gallon can with half a gallon of diesel in it mix with Grotamar 82 for shock dose of the ammount of fuel in tank shake it well and add to the tank, otherwise if you just pour it into the tank it wont disperse very well in a static boat.

At current tmperature it takes about a week for the Grotamar 82 to do its job.

I would also try and strip out water from the bottom of the tanks, do you have sumps in the tanks to strip from.

It may be worth passing the disel through a filter before next use.
 
Bandit said:
I use Grotamar 82 which is formulated for biodiesel , I would get a gallon can with half a gallon of diesel in it mix with Grotamar 82 for shock dose of the ammount of fuel in tank shake it well and add to the tank, otherwise if you just pour it into the tank it wont disperse very well in a static boat.

At current tmperature it takes about a week for the Grotamar 82 to do its job.

I would also try and strip out water from the bottom of the tanks, do you have sumps in the tanks to strip from.

It may be worth passing the disel through a filter before next use.
Click to expand...

As I understand it, Grotamar is the same as Marine 16.
 
gregorymc said:
Cheers lads, have been able to have a look in though the sender hole and the fuel looks clean. So will leave the fuel in the tank and treat as you suggest. Thanks
Click to expand...

I would doubt you would get a true idea of how clean the fuel is just by peering down onto it through the sender hole!
And FWIW being only 50/60 ltrs in the tank if it were me I'd pump the lot out into containers and if its ok store it until next season, get a transfer pump set up or make one (easy enough) and poke and prod all the corners of the tank, then do it again until you are sure its clean....
Leave the tank empty and leave the sender hole open but place some gauze over the hole, allowing it to breath while in winter mode!
Next season you can start afresh with no concerns about your fuel whatsoever..
Rob.
 
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A word of warning on using Grotmar. It is very effective but produces a lot of precipitates in doing its job which will end up blocking your filters. Also, don't get any of it on Aluminium when its neat (it glued the fuel filler cap solid on our boat). I have found Startron a better all round preventer of bug/water absorbtion. If you already have bug, the Grotmar will be the most effective, with the above caveats.
 
Thanks again for your input. I think i'll pump it out next chance I get and will be a lot happier to start next season on fresh fuel.
It was hard enough to convince the other half on the benefits of Motor-boating without it breaking down first few days of the season.
( especially now I don't have a sail to fall back on.)
 
robmcg said:
A word of warning on using Grotmar. It is very effective but produces a lot of precipitates in doing its job which will end up blocking your filters. Also, don't get any of it on Aluminium when its neat (it glued the fuel filler cap solid on our boat). I have found Startron a better all round preventer of bug/water absorbtion. If you already have bug, the Grotmar will be the most effective, with the above caveats.
Click to expand...

The precipitates you refer to are the dead bugs and their excreta breaking off and getting caught in the fuel filter so make sure you have spare fuel pre filters available like two sets in case of a blockage at sea.

Pesonally I do not want to absorb water I want to remove it from my tank with a stripping line, water absorbed or not and fuel pumps / injectors do not mix well.
 
The only down side of emptying the tank, is that you will gather a lot of water through condensation. No problem when there is no diesel in the tank, but you will need to empty this before filling up with diesel next season.
 
Bandit said:
The precipitates you refer to are the dead bugs and their excreta breaking off and getting caught in the fuel filter so make sure you have spare fuel pre filters available like two sets in case of a blockage at sea.

Pesonally I do not want to absorb water I want to remove it from my tank with a stripping line, water absorbed or not and fuel pumps / injectors do not mix well.
Click to expand...

Unfortunately the precipitates are not just dead bug with this product. It is derived from the stuff they treat huge storage tanks of fuel with. In our boats case, it produced huge amounts of precipitates even though the fuel tested negative for bug. It was added as a preventative measure which isn't its strongest suit. I have subsequently found many people who have had the same experience.
 
robmcg said:
Unfortunately the precipitates are not just dead bug with this product. It is derived from the stuff they treat huge storage tanks of fuel with. In our boats case, it produced huge amounts of precipitates even though the fuel tested negative for bug. It was added as a preventative measure which isn't its strongest suit. I have subsequently found many people who have had the same experience.
Click to expand...

Hi robmcg. This is an interesting comment. Being somewhat paranoid about the fuel on Play d'eau, can you give some more specific info on your findings? Seeing you are in education, can you educate me, please!

Piers
 
Having not had diesel bug in either of the fuel tanks (tested negative on every occasion) it was decided that prevention was better than cure and with Grotmar having a good reputation as a bug killer it was added to both tanks in the correct doses. The result was a precipitate that collected in the primary fuel filter that caused the engine to 'hunt' and made its way as far as the fine filter, gumming shut the plastic drain on the bottom of the filter. Without scientific analysis, it looked like it had reacted with something in the fuel, tank or lines and made a sludge that didnt look like the black bits or jelly like stuff that you usually see from bug. Fuel was removed, polished, tested (negative) and returned to the tank after it had been cleaned manually. All the flexible fuel lines were also replaced as a precautionary measure. Since then there hasn't been a reoccurrence. I now use Startron which seems to be a good preventative measure. The experience above only happened once after the addition of Grotmar. I think if you already have bug then it is probably the most effective stuff out there - but there was an obvious reaction with something in the fuel system after it was added. It could have been a reaction with another product that was added to the fuel when it was in storage before being bought. The experience has just made me wary in the future. Asking around, I have found others who have experienced similar issues - but that might have been dead bug blocking up the works as the stuff seems super effective at doing that. If however you are using it and are not experiencing this type of issue, I don't see any need to stop using it. The problem has not reoccurred since, but we haven't used Grotmar since then either.
 
Robmcq
Did you have a fuel sample taken, spread in an agar bottle and grown for 3 days in an incubator, which is the normal way of doing it?

Fuel bug grows on the interface between water at the bottom of the tank and the diesel above it also sticks to the sides of the tank and tank baffles, I have seen it on boats ( not mine) up to 10mm thick like an oxtail soup in consistency.

I have also seen lumps of it blocking fuel lines almost the consistency of fresh chewed chewing gum ( not that I chewed it).

When you dose with Grotamar 82 it kills the bug and the bug and the mat of slime falls off and starts to break up and if you don't filter the tank remotely the only place the slime and bits can go is to get stuck in the diesel pre filter and when that is full it will go to the engine mounted filter as well .

If you have a filter with a removable element such as the Racor or Volvo Penta filter with an open element it is easy to monitor the condition of the filter and change it if it starts to block up. If you have a filter built in to a steel can such as Fleetguard you will not see it unless you cut the can open which is quite difficult.

Knowing when to rely on the engine prefilters or when to remotely filter the diesel yourself or using a contractor is a judgement call.

Either way you need a couple of sets of spare prefilter on board and you need to remove any water from your tank at every opportunity. I have a sump on my tanks and I drain the water and any crud using a Pella engine oil vacuum pump reserved solely for this.

If water in your fuel gets to a mechanical fuel pump and injectors it is very expensive, if it gets to a common rail fuel pump and injectors it is very, very expensive, so best to treat it at all times with a good biocide and remove all water at every opportunity from your tank.

Water will also cause corrosion in steel tanks and with fuel bug this is more acidic and damages the steel of a tank and corrodes aluminium tanks badly. I have seen ally tanks from a british production line boat that had to have the bottoms and lower couple of inches of the sides at under 5 years old.

I would not rely on a product such as Startron to remove all water from your tank, it cant. Also I would not let water even water that has been absorbed by a product such as this anywhere near my fuel pumps.
 
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Bandit said:
Robmcq
Did you have a fuel sample taken, spread in an agar bottle and grown for 3 days in an incubator, which is the normal way of doing it?

Fuel bug grows on the interface between water at the bottom of the tank and the diesel above it also sticks to the sides of the tank and tank baffles, I have seen it on boats ( not mine) up to 10mm thick like an oxtail soup in consistency.

I have also seen lumps of it blocking fuel lines almost the consistency of fresh chewed chewing gum ( not that I chewed it).

When you dose with Grotamar 82 it kills the bug and the bug and the mat of slime falls off and starts to break up and if you don't filter the tank remotely the only place the slime and bits can go is to get stuck in the diesel pre filter and when that is full it will go to the engine mounted filter as well .

If you have a filter with a removable element such as the Racor or Volvo Penta filter with an open element it is easy to monitor the condition of the filter and change it if it starts to block up. If you have a filter built in to a steel can such as Fleetguard you will not see it unless you cut the can open which is quite difficult.

Knowing when to rely on the engine prefilters or when to remotely filter the diesel yourself or using a contractor is a judgement call.

Either way you need a couple of sets of spare prefilter on board and you need to remove any water from your tank at every opportunity. I have a sump on my tanks and I drain the water and any crud using a Pella engine oil vacuum pump reserved solely for this.

If water in your fuel gets to a mechanical fuel pump and injectors it is very expensive, if it gets to a common rail fuel pump and injectors it is very, very expensive, so best to treat it at all times with a good biocide and remove all water at every opportunity from your tank.

Water will also cause corrosion in steel tanks and with fuel bug this is more acidic and damages the steel of a tank and corrodes aluminium tanks badly. I have seen ally tanks from a british production line boat that had to have the bottoms and lower couple of inches of the sides at under 5 years old.

I would not rely on a product such as Startron to remove all water from your tank, it cant. Also I would not let water even water that has been absorbed by a product such as this anywhere near my fuel pumps.
Click to expand...


Tested with this kit - http://www.force4.co.uk/5097/Force-4-Marine-16-Diesel-Bug-Test-Kit.html

Startron has proved more effective in my application than the Grotmar was. From my experience, I wouldn't want to use the stuff again - unless the tank tested positive for bug, then I believe it would be very effective.
 
I don't see anything wrong with the test kit other than I cant see how it neutralises a biocide.

Quote Robmcg
Grotmar having a good reputation as a bug killer it was added to both tanks in the correct doses. The result was a precipitate that collected in the primary fuel filter that caused the engine to 'hunt' and made its way as far as the fine filter, gumming shut the plastic drain on the bottom of the filter. Without scientific analysis, it looked like it had reacted with something in the fuel, tank or lines and made a sludge that didnt look like the black bits or jelly like stuff that you usually see from bug. Fuel was removed, polished, tested (negative) and returned to the tank after it had been cleaned manually. All the flexible fuel lines were also replaced as a precautionary measure.

I don't think it was a precipitate you had but dead fuel bug and its bi product excreta which after a biocide application was breaking up. If you have had a good dose of the bug there is a fair amount of mat and debris to clear out hence the partial blockage and hunting.

By polishing the fuel, manually cleaning the tank and replacing flexible fuel lines you did the right thing. Probably if you had continued with Grotamar you would have had the same result?

I stand by my comments about removing water and the other comments I made above.
 
Hi Bandit,

I have never tested to see what's lurking at the bottom of Play d'eau's four fuel tanks. There's no sump access, but the fuel filler caps have straight access to the tanks - no bends, Might it be sensible for me to use a long hard pipe on the end of a Pella (for example) and see? I somehow dread the possible result, although I have always treated the fuel since I bought her in 2003 and never had a problem.

Piers
 
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