Cleaning out diesel fuel tank

jollyboy

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After a heart stopping moment when my engine nearly cut out while passing the Landerne pier at Caernarfon, I decided it was time to clean the fuel tank. After much sweating and cursing, I have managed to remove the tank from the bilge of my Albin Vega. I am not sure to what extent I need to "clean" it, other than washing it out with detergent. Does anyone have any views? The tank is made (according to the Vega handbook) out of "polyamid" plastic. I've heard of people steam cleaning their tanks. Does it really need that? If I simply wash it so that it appears visually clean, will that be enough? Any thoughts?

John Booth
Vagrant 1718
 
if you have the tank out of the boat, then it's easy to put in one of Oiltechnics biological cleaners,with some warm water and leave it for a day or two for the benevolent bugs to eat up all traces of hydrocarbons.

www.oiltechnics.com.

Very good telephone support team.


(no affiliation, bTW)


Then when you re-install, a few drops of Grotomar or Marine 16 to keep the fuel from picking up any airborne bacteria.
 
After a heart stopping moment when my engine nearly cut out while passing the Landerne pier at Caernarfon, I decided it was time to clean the fuel tank. After much sweating and cursing, I have managed to remove the tank from the bilge of my Albin Vega. I am not sure to what extent I need to "clean" it, other than washing it out with detergent. Does anyone have any views? The tank is made (according to the Vega handbook) out of "polyamid" plastic. I've heard of people steam cleaning their tanks. Does it really need that? If I simply wash it so that it appears visually clean, will that be enough? Any thoughts?

John Booth
Vagrant 1718

Just done mine - very hot soapy water and sponges/scourers. Slosh the hung around a lot. Repeat.

Dry between repeats using kitchen roll (carefully) until it comes away white.

Do a blast clean with bug treatment as well. Seemed to work well enough, pretty sure this is a minimum treatment but it worked and wasn't a nasty job. I did look into the tank treatment (some flow-coat treatment sold for about £50 a go) but there was just no need.
 
Many thanks Sarabande, that was quick!! I'm wondering what the relative benefit of using a cleaner like that is. What would happen if I only washed it with detergent? Would the bugs be back in the tank within a few days/weeks/months?
 
the Oiltechnics biocleaner is very very good. It eats up every molecule of diesel/petrol, and can then be disposed of without recourse to special waste regulations, leaving a tank that just needs to drain dry before reinstalling.

The acquisition of malevolent bugs in tanks is primarily from the fuel itself, with secondary contamination from airborne bacteria and water in the condensing mode via the breather - hence keep the tank as full as you can.

If you have a really clean tank, and a good source of fuel, then not much to worry about, but why not make sure with a few drops of bug killer. Bacteria grow mostly in the interface layer between fuel (light) and water (heavy) so keeping water out is important.

If you have a diesel, the return pipe / injector pump system will normally heat up the fuel enough to keep most water particles at bay.
 
After a heart stopping moment when my engine nearly cut out while passing the Landerne pier at Caernarfon, I decided it was time to clean the fuel tank. After much sweating and cursing, I have managed to remove the tank from the bilge of my Albin Vega. I am not sure to what extent I need to "clean" it, other than washing it out with detergent. Does anyone have any views? The tank is made (according to the Vega handbook) out of "polyamid" plastic. I've heard of people steam cleaning their tanks. Does it really need that? If I simply wash it so that it appears visually clean, will that be enough? Any thoughts?

John Booth
Vagrant 1718

I would agree with all the previous advice you have had, basically a simple clean out is all that is required, and replace your filters to.

I have installed a fuel polisher which filters fuel from the tank using a separate 12 v pump, my 4108 has a manual one, through two filters and returns the 'polished fuel' to the tank, which ensures my primary filters always get clean deisel.
I did this after a similar experience to yours, following a fill of fuel which turned out to have dirt and water in it, my engine stopped in a busy place leaving Santa Teresa in Sardinia, in a ferry lane of all places, and no wind, changing the filters was a nightmare as the were passing me doing 10 to 20 knots, causing me violent rocking whilst doing the change and subsequent bleeds, took nearly two hours.
I can also redirect the polished fuel via a three way valve to my filters so no more manual pumping now thank goodness.
I have the schematic diagram if it would be of interest to you.
 
Hi Sarnia, many thanks. Let me take advice from the Engineering Officer and I will come back to you on that! I am just in the process of replacing the gravity (primary) filter with one that has a manual pump built in, to lift fuel from the tank up to the gravity filter. It doesn't (as far as I am aware) also polish the fuel. I'll come back to you.

John Booth
Vagrant 1718
 
Biggest problem with my tanks, cleaned this winter was years sludge and sand deposited in the bottom that shook itself up when it got rough.

Your soapy wash should sort that but i'm also bug paranoid now and put additive in and each fill
 
My yard recommended a couple of mugfulls of pea gravel with a few litres of fuel, swirl around thoroughly getting it to all corners, drain off, add more clean fuel, swill around thoroughly again, drain off and remove gravel (fun if the filler neck is lipped inside). Rinse again with fresh fuel, and voila! Sparkling clean tank.

I didnt think it would work either. But it did, the gravel scours out the interior very effectively.
 
My yard recommended a couple of mugfulls of pea gravel with a few litres of fuel, swirl around thoroughly getting it to all corners, drain off, add more clean fuel, swill around thoroughly again, drain off and remove gravel (fun if the filler neck is lipped inside). Rinse again with fresh fuel, and voila! Sparkling clean tank.

I didnt think it would work either. But it did, the gravel scours out the interior very effectively.

Detete the pea gravel and change for 5/16 UNF nuts and thats how we cleaned rusty motorbike tanks.

Worked every time.
 
I have been asked by other members for the circuit diagram of my fuel polisher, it is on a word doc. and I cant find a way to put it on here.
If you wish to have a copy please PM me with your email address and I will send it that way to you.

If someone knows how I can put it in here please let me know and I will.
 
After a heart stopping moment when my engine nearly cut out while passing the Landerne pier at Caernarfon, I decided it was time to clean the fuel tank. After much sweating and cursing, I have managed to remove the tank from the bilge of my Albin Vega. I am not sure to what extent I need to "clean" it, other than washing it out with detergent. Does anyone have any views? The tank is made (according to the Vega handbook) out of "polyamid" plastic. I've heard of people steam cleaning their tanks. Does it really need that? If I simply wash it so that it appears visually clean, will that be enough? Any thoughts?

John Booth
Vagrant 1718

Hi John

One tip if you plan to clean your tank out at home, DO NOT clean it on the lawn, old traces of diesel will kill the lawn dead, and I mean very dead to the point you will need to returf!

How do I know ? three years after the wife still reminds me, even more as the two sq yards of new turf is still a differant green to the old turf

Mike
 
Hi John

One tip if you plan to clean your tank out at home, DO NOT clean it on the lawn, old traces of diesel will kill the lawn dead, and I mean very dead to the point you will need to returf!

How do I know ? three years after the wife still reminds me, even more as the two sq yards of new turf is still a differant green to the old turf

Mike

You go boating and you have a lawn-how quaint.............................
 
Hi John

One tip if you plan to clean your tank out at home, DO NOT clean it on the lawn, old traces of diesel will kill the lawn dead, and I mean very dead to the point you will need to returf!

How do I know ? three years after the wife still reminds me, even more as the two sq yards of new turf is still a differant green to the old turf

Mike

Aha! I have that teeshirt as well!
 
Hi Euan and Old Harry,

Yes, the problem on Vagrant started in rough weather with a quarter full tank. I have since then used Starbrite fuel cleaner. The problem is at least partly due to the fact that the engine uses so little fuel, that I only normally have to fill up once or twice a season, so the bug has quite a time to develop. As regards Old Harry's comments on using pea gravel, I guess that's not necessary in my case, as the hole into the fuel tank is very large. I can get my arm in! It also has very rounded corners so there's no little murky corners that I can't reach. It's only 35 litres in size. Many thanks for your advice!

John Booth
Vagrant 1718
 
Many thanks Sarabande, that was quick!! I'm wondering what the relative benefit of using a cleaner like that is. What would happen if I only washed it with detergent? Would the bugs be back in the tank within a few days/weeks/months?

Nothing much due to the cleaning method. The bugs are in all diesel. What will stop it coming back is dosing with bug killer.

I used gunk to degrease the tank, then hot soapy water and finally the lance of the pressure washer. Thoroughly dry. Done it three times now on three different boats ( each time just after I bought the boat). Never come back yet.
 
I drain mine every couple of years (via a syphon to the very bottom, not the fuel take-off point) and put an endoscope into it to confirm it is clean. Very hard to take it out. It is best to keep the tank full.
Now that you have it clean it is important to filter every drop that goes into it (especially any from questionable or low-volume sources). I recently bought a “Mr Funnel” from the US - it filters out water and particles (there are others). Their video and praise from other yachties convinced me. You need to pour any additives directly to the tank, not via Mr Funnel. Andrew (no connection)
 
Unless you always fill from cans, a filter funnel may be too slow to pass the fuel from a normal pump.

The dreaded bug needs water to grow. If you can keep the bottom of the tank reasonably free of water, you won't get enough bug growth to clog the filter.
It helps if the tank has a sump where the water collects.
Hoovering the water out of the bottom of the tank with a Pela once or twice a season seems to keep us out of trouble.
A polishing system might be more elegant.
If I ever install a fuel system, I shall go for a small 'day tank', so that if the filter clogs you can add clean fuel from a can to the day tank.
I always like to have a few litres of known good fuel in cans. Not needed it myself yet, but it trades well!
 
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