Fill her up ??

[Halo]

I have been told that it is a bad idea to fill up the diesel tank before winter. This is against conventional wisdom but seems scientifically sound.
Modern diesel is unstable with veggie oil and fats in it. It has been found that after a few months shelf life it deposits sludge in the tank. Over winter this will happen especially if some of your diesel is already old. Less diesel makes less sludge and turns over faster.
The purpose of filling the tank is to reduce the air volume and hence condensation. A better solution for this is to fit a desiccant drier / filter on the breather.
A low tank is not ideal in bad weather but what do you think about over winter?

 

[Ribtecer]

I keep mine brimed all year round.

 

[38mess]

Does this apply to red?

 

[Halo]

Yes it applies to red. It’s same as white plus colour

 

[Porthandbuoy]

My local marina, Rhu, state their diesel is FAME (Fatty Aromatic Methyl Ester) free. Isn’t that the case with most marinas?

I won’t be topping my tanks up, but I will circulate the fuel through the polishing system occasionally over the winter. I installed a pump and filter when I bought Sheolin as she had lots of diesel bug having been laid up for 5 or 6 years.

 

[diverd]

Diesel bug appears to be a real problem, and some year a huge percentage of boats travedling long distances to our marina break down because of it. I was involved in 3 deliveries last year, and all 3 had diesel bug problems in the tanks, which we either cleaned or bypassed with external tanks. I know the additives help, but literally every tank i have looked in have had some. My take now is to empty the tank before laying up the boat, let it dry out and it cannot give problems. Most years i run a boat through the winter, and in this case i will just keep running the tank down, and at some point will empty it, clean it and start again. Anything else appears to be some form of gamble if you are not using the boat regularly. Filling the tanks helps reduce condensation, which is a great idea if you know the tank is totally clean, of not, it just makes the problem larger!

 

[Sandy]

I empty my tank during the winter. One reason I use white is I can transfer it to the car and it works out cheaper than red for me. Saw red at £1.75 a ltr in Falmouth this summer when I was paying £1.45 at my local garage.

The tank gets a clean and I don't have >£150 of diesel sat around doing nothing.

 

[Parabordi]

The purpose of filling the tank is to reduce the air volume and hence condensation. A better solution for this is to fit a desiccant drier / filter on the breather.

I can see how this would stop damp air entering the tank, but isnt the issue more the temperature difference ie tank is much warmer than the air around it?

 

[lustyd]

It has been found

Go on then, links please to a reputable source so we aren't starting another pointless rumour thread

 

[vyv_cox]

Condensation in yacht fuel tanks just does not happen. See here Does an Empty Marine Fuel Tank Condensate? - Marine How To

I have left my fuel tank however it finished up at the end of the season, full, empty or at various levels in between for the past 30 plus years. I never use additives and have never had diesel bug. I ensure that rain or sea water cannot get into the filler, by ensuring the O- ring is good, greasing occasionally and having a winter cover over it

 

[Bristolfashion]

Condensation in yacht fuel tanks just does not happen. See here Does an Empty Marine Fuel Tank Condensate? - Marine How To

I have left my fuel tank however it finished up at the end of the season, full, empty or at various levels in between for the past 30 plus years. I never use additives and have never had diesel bug. I ensure that rain or sea water cannot get into the filler, by ensuring the O- ring is good, greasing occasionally and having a winter cover over it

Ah, a winter cover, that's a really good idea - do you have something sophisticated or just a taped down piece of plastic?

 

[penberth3]

Condensation in yacht fuel tanks just does not happen. See here Does an Empty Marine Fuel Tank Condensate? - Marine How To

I have left my fuel tank however it finished up at the end of the season, full, empty or at various levels in between for the past 30 plus years. I never use additives and have never had diesel bug. I ensure that rain or sea water cannot get into the filler, by ensuring the O- ring is good, greasing occasionally and having a winter cover over it

ISTR this subject was done-to-death a few months ago? Conclusion was condensation is negligible, most of the water comes with the fuel, i.e. you're buying it!

 

[Parabordi]

Condensation in yacht fuel tanks just does not happen. See here Does an Empty Marine Fuel Tank Condensate? - Marine How To

I have left my fuel tank however it finished up at the end of the season, full, empty or at various levels in between for the past 30 plus years. I never use additives and have never had diesel bug. I ensure that rain or sea water cannot get into the filler, by ensuring the O- ring is good, greasing occasionally and having a winter cover over it

Mine does, drained it one year and when put hand in thru inspection hatch it was dripping wet

 

[vyv_cox]

ISTR this subject was done-to-death a few months ago? Conclusion was condensation is negligible, most of the water comes with the fuel, i.e. you're buying it!

As it comes from the refinery, fuel has a very low water content, from memory <0.2%. Transport can add water enormously, floating fuel bunkers being particularly suspect. I know of one in Greece where the water content was measured at 50%!

 

[vyv_cox]

Ah, a winter cover, that's a really good idea - do you have something sophisticated or just a taped down piece of plastic?

Not sure it qualifies as sophisticated but it is a fitted plasticised acrylic cover very well held down. We have had three since around 1995, replaced as they wore out. We made the first two, third one made professionally in Leros and substantially repaired after covid.

Invaluable on a boat that stands unattended for nearly half the year.

 

[Plum]

I have left my fuel tank however it finished up at the end of the season, full, empty or at various levels in between for the past 30 plus years. I never use additives and have never had diesel bug. I ensure that rain or sea water cannot get into the filler, by ensuring the O- ring is good, greasing occasionally and having a winter cover over it

and I have had the same experience over the last 35 years

 

[NormanS]

I always leave mine full, and have generally found the fuel in the tank to be worth more in the Spring, than I paid for it in the Autumn.

 

[MontyMariner]

I always leave mine near full, never had an issue. Next fill is always more expensive!

 

[Halo]

Go on then, links please to a reputable source so we aren't starting another pointless rumour thread

I did give full details in a previous posting but it was deleted presumably because it gave links to a well known product.
I got the information from marinechandery.com who publish top tips and issue number 470 applies.

 

[Halo]

I did give full details in a previous posting but it was deleted presumably because it gave links to a well known product.
I got the information from marinechandery.com who publish top tips and issue number 470 applies.

Or you can P M me if you want