What Do You Do With Your Fuel Tank/ System

[jackson]

Hello, NOT OWNING A BOAT FOR TWENTY YEARS,I CONSIDER MYSELF A NEWBY,   What  to do with my  diesel  tank  and fuel system. i will shortly be putting it to bed for the winter, any advice appreciated l

[Smoggy]

Dose the tank well with a good bug treatment, I use marine 16 but others have different preferences,  as for empty or full the jury seems to be out. 

Check for water in tank in spring and re-dose.

[maysailor]

I have the engine serviced and winterised  including new primary and secondary fuel filters and I top the fuel tank up,

 

[annv]

Hi Jackson just fill tank with F A M E fuel or the new gas derived fuel turn tank tap/valve of then just leave it till spring where you drain water trap or if no water drain off push a 1/4 dia pipe into the lowest part of tank and suck any water out, change fuel filter if due at end of season or before lay up, and its good practice to (if you have one) to grease prop seal then turn prop by hand one turn this will stop water drip and keep bilges dry over winter plus what ever else you think and if possible lots and lots of ventilation to inertia. John

[Vaughan]

The main thing is to leave the tank full over winter.

That way there is no air space to cause condensation, which is why water accumulates in the bottom. Hence all this stuff about diesel bug.  Personally, I don't believe in it.  If the tank is full of diesel, you won't get any water in it!

[OldBerkshireBoy]

23 minutes ago, Vaughan said:

The main thing is to leave the tank full over winter.

That way there is no air space to cause condensation, which is why water accumulates in the bottom. Hence all this stuff about diesel bug.  Personally, I don't believe in it.  If the tank is full of diesel, you won't get any water in it!

Seems a strange thing to say that you dont believe in the existance of diesel bug.

[rightsaidfred]

1 hour ago, Vaughan said:

The main thing is to leave the tank full over winter.

That way there is no air space to cause condensation, which is why water accumulates in the bottom. Hence all this stuff about diesel bug.  Personally, I don't believe in it.  If the tank is full of diesel, you won't get any water in it!

Yes has worked perfectly well for me over the years and never had a problem, never wasted money on additives either for boat or cars.

Fred

[PCL023]

Topping off fuel tanks, topical 😊, we should all rush out now and get them filled. I can see the news now, boats queuing out from either side Horning for fuel 🤣

[colino]

Always fill every winter

[Vaughan]

3 hours ago, OldBerkshireBoy said:

Seems a strange thing to say that you dont believe in the existance of diesel bug.

No I don't.

In a lifetime in the inland waterways boating business, I had never heard of it until I joined this forum.

During  a hard winter, you will get a deposit of paraffin wax which separates out from the diesel  when it freezes in the pipes.  This is harmless but it has a thick consistency which can clog filters and sediment traps.

This why we always change fuel filters in the spring, after the cold weather is over.

I believe it is this wax residue that may be what is known as diesel bug.

[rightsaidfred]

Keep mine filled all year round just top up when having pump out, no one big bill and no worries about forgetting or running low

Fred

[grendel]

2 minutes ago, Vaughan said:

During  a hard winter, you will get a deposit of paraffin wax which separates out from the diesel  when it freezes in the pipes.  This is harmless but it has a thick consistency which can clog filters and sediment traps.

this was the stuff that came out of the bottom of Water Rails filter, it oozed out as one lump and had filled the bottom half inch of the filter housing, this was restricting the flow and limiting me to about 2000 rpm.

[Smoggy]

27 minutes ago, Vaughan said:

In a lifetime in the inland waterways boating business

Inland is the key word there, I wouldn't worry about it all inland as the sludge settles to the bottom of the tank and rarely causes any problems, half the boats on the broads probably have a tank base covered in thick sludge and will never know about it.

Get out on a bumpy trip when the weather didn't play as expected and it all gets stirred up causing the grief, I don't mean a bumpy trip across breydon on a windy day I mean a proper good north sea shake up.

[rightsaidfred]

47 minutes ago, Smoggy said:

Inland is the key word there, I wouldn't worry about it all inland as the sludge settles to the bottom of the tank and rarely causes any problems, half the boats on the broads probably have a tank base covered in thick sludge and will never know about it.

Get out on a bumpy trip when the weather didn't play as expected and it all gets stirred up causing the grief, I don't mean a bumpy trip across breydon on a windy day I mean a proper good north sea shake up.

While I and probably many others appreciate that this is a Broads forum and I for one take it that questions on here relate to boats used on the Broads not sea going.

Fred

[Meantime]

19 minutes ago, rightsaidfred said:

While I and probably many others appreciate that this is a Broads forum and I for one take it that questions on here relate to boats used on the Broads not sea going.

Fred

A forum that does contain an Offshore Area for discussions regarding offshore boating, and there's even been some posts in it this year.

 

[Vaughan]

26 minutes ago, rightsaidfred said:

While I and probably many others appreciate that this is a Broads forum and I for one take it that questions on here relate to boats used on the Broads not sea going.

As we are on the subject, a lot of this has to do with mild steel fuel tanks.

If the tank is not full, then condensation will occur in the air space (see above), which will rust the inside of the tank.  This will sink to the bottom and cause a watery brown sludge, about which we all complain!

A stainless steel tank, kept full in winter, should not accumulate rusty sludge, unless it was in the diesel before it got into your tank!  In other words, don't buy diesel from a small bankside outlet which may not sell much, so the diesel itself may have been in the bulk tank for a year or more.  Subject to the same condensation and rust in winter.  (see above).  Moral of the story : it may be cheaper when you buy it but you may pay for it in the "long run".

An offshore boat has baffles in the tank to prevent the fuel slopping about and stirring up sludge in the bottom. A Broads boat may have a few baffles but probably not enough for going offshore. "Horses for courses".

I would never go offshore in a Broads boat without a box of spare filters and preferably, a dual feed bypass filter system.

[annv]

Hi Vaughan It is only recently that boat diesel is now the same as road diesel that has 5%to 10% palm oil added to make it more particulate free this palm oil or F A M E is what causes the diesel bug which feeds on the palm oil at the water boundary in bottom of tank not noticed in cars as they empty there tanks regularly,  boats that often dont fill there tank/empty there tanks for long periods boat and stand still can get it,  marine diesel has no palm oil added and has a higher concentration of sulphur so traditionally hasn't had this problem until recently now we are more environmentally aware we now have problems that we didn't have before if you google diesel bug there is a lot of information about this like you i have never experienced before  when i become  aware i made sure i only used marine diesel easy on my last boat as i had a 1000lt at a time by tanker from Somerlation oils when required i then i used at Burgh Castle as they only have marine diesel. Hope this helps. John

[annv]

Hi Smoggy A force five is reconded to be the state to stir the crap up. John

[Vaughan]

4 minutes ago, annv said:

Hope this helps. John

Yes it does, thank you John.

What you describe appears to be sediment which accumulates on the water level at the bottom of the tank, so regular inspection of the sediment trap filter and regular fuel filter changes should prevent this, I would hope.

Almost all hire boatyards will change their filters once during the season and sometimes twice, if fully booked up.

[rightsaidfred]

26 minutes ago, Meantime said:

A forum that does contain an Offshore Area for discussions regarding offshore boating, and there's even been some posts in it this year.

 

Agreed but unless specified I take general questions to relate to Broads boats not sea going.

Fred

[annv]

Hi Vaughan Yes i have never seen it in the flesh so to speak only in pictures its a bug that grows and then dies leaving a sludge that gradually increases and blocks the filters hire boats probably dont get it as they turn there fuel over more often and keep there tanks full over winter along with proper maintenance. John

[TheQ]

I've had diesel bug on the boat, stainless steel tank, thick black sludge which made its way through and clogged the engine filter on the pump and the inline fuel filter..

When I pumped out the tank, I took several gallons of water out of the tank. I suspect the previous owners didn't keep the tank full, as I do when moored over the winter. Though before this I didn't add Additives as I do now.

So I built my own fuel polishing system. The first few times removed more water from the fuel and some sludge. If I'm spending the day working on the boat i'll set up the polisher and leave it running, Just as a precaution.

 

[Cheesey69]

It must be remembered that pure diesel has water naturally present in it. 
given time and enough fill ups every tank will develop a layer of water. 
All our back up generator packs have a drain plug in. 
you would be surprised at what comes out. 

[Smoggy]

When I had the problem I rigged a polishing system from the tank drains pumped through a large 10" filter canister and back to a vent fitting at the top rocking the boat as much as possible, the crud that came out was hideous and lots of it from both tanks and was a bit like black blanket weed in appearance definately not waxy, once cleared it was rust flakes that caused the next seasons issues (yep mild steel tanks) as the sludge was holding it in place, finally a small red stain below a tank seam made the choice that they need replacing, this involved both engines out to get to them which was no small task (1/2 ton each and had to go up through a sunroof with an inch to spare) and new stainless tanks made, my tanks were baffled as I cut the bases out to see how bad they were.

.

Diesel bug happened before FAME just not nearly as badly.

My boat spends most of it's time on the broads as well as going to sea when the opportunity arrises as do many others and not knowing the OP's boat or planned usage I think it's perfectly acceptable to include the info, do remeber the broads is not a closed in river system it's one big tidal haven.

My worry now is that due to lockdowns I still have nearly full tanks of fuel bought in 2019 although been well dosed and re-dosed several times.

 

 

[BroadAmbition]

Imho, prevention is always far better than a cure, and always far better than blocked / filters and a breakdown.

Broads boats not going to sea? - Really?  Well I have taken 'B.A' down to the Thames, Southwold, and Ipswich marina.  Also had a play about outside the breakwaters with two RN patrol boats along with MTB102.  Done the Gt Yarmouth to Mutford lock a few times now too.  It has been muttered amongst us four owners to go over to Holland too, although all we have done is lightly talk about it.

Whatever, each time I go over a choppy Breydon, or venture out onto the salty crinckly stuff, I need to have confidence with 'B.A's diesel system.  Since we have been her custodians back in 2007, to date never an issue, that's not luck or coincidence, it's because we take sensible measures / steps.

Firstly we replaced the ageing mild steel tank with a s/steel unit, but this one has a sump and a drain key / plug.  Every two years I get down there (Which is proper awkward btw) and run off diesel from the sump into a clear see through container.  The last time I did this was coincidentally this month!  Clear as a bell with no contamination which was to be expected.  That's because we always leave the diesel tank brimmed full when tucking her up in t wet shed, all year round, not just in the winter.  We always add Soltron every fill too (Other types are available).  We get our fuel from well used yards that have a high turnover, preferably those with plastic bulk storage but not always

The filter / water separator onboard is of the see through type so the diesel can be viewed at a glance, you can also see the micron filter too which is removable for cleaning.  I have full confidence in the diesel system onboard.  That Thames trip - The return was was proper stormy with poor 'B.A' getting tossed around like a cork, the Beta never missed a beat, that was five years after the fuel system was first commissioned

Griff