diesel

[Alan Hensler]

Was planning on topping up the diesel tanks shortly they are about 50 % full.
Then had a very interesting email from Marine 16 about not filling tanks up for winter
This is the article:
Modern diesel is highly unstable, it’s been refined to within an inch of it’s life to remove the sulphur and now it has 7% plant oil along with animal and cooking fats. It degrades very quickly producing sludge that ends upon the bottom of your tank. The stability improver and antioxidant we blend into Marine 16 Diesel Fuel Complete (DFC) helps slow some of the degradation, but it cannot be fully prevented or reversed, would you get a blackened banana in the fruit bowl and try and recover it? No? you can’t, it’s same with diesel, it just doesn’t go as black.
So here at Marine 16 we recommend running the fuel tank down to as empty as possible. Get as much water out as you can, if you can, and put in a kill dose of Diesel Bug treatment (DBT) to kill any bug over the lay up that might try and take refuge in your tank. You can stop the moisture entering the tank by fitting a desiccant breather on the vent. This will dry the air as it is drawn into the tank so it cannot condense on the sides. Available on our website soon.
Additionally add a dose of Diesel Fuel Complete (DFC), even if you have been using it. From our research with fuel testing laboratories throughout this year we have improved DFC with an additional antioxidant in the blend in an attempt to mitigate the continued degradation of the FAME (The bio bit in the Diesel) which leads to carboxylate acid. We can’t stop the degradation, see above about the banana, but along with the dispersant in the blend this will help reduce deposit formation on the bottom of the tank.
When you return in the spring, drain any water from the drain cock or push a pipe down the filler to the bottom to try and draw off any accumulated water, or fit a diesel dipper over layup that can do it for you. If you invested in a desiccant breather there be should be very little anyway.
You should now be able to fill up the tank with clean fresh diesel but don’t forget to add, and keep adding, Diesel Fuel Complete (DFC) which will help mitigate the problems of storing it longer than 6 months, which is inevitable as you enjoy the summer, especially if you’re sailing.

What do you all think of this solution????

Thanks Alan

 

[BruceK]

All the additive companies are saying the same thing. Two possibilities. 1) they are trying to drum up business 2) Would you start a business that requires significant investment based on a scam? I'm inclined to believe them though sceptical of the heightened risk implied. i.e. the risk is real but you'd be unlucky rather than guaranteed a problem. Just my thoughts without any scientific backup.

 

[sarabande]

"well, they would say that, wouldn't they ?"

Disregarding the advertising puff about making a virtue of a necessity WRT the bio aspect of the new diesel, there are some questions.


Do all diesels supplied to marinas, or other suppliers, have bio ethanol ? I understand that not all blends are equal.


The dessicant breather bothers me a bit. How much water removed from the inevitable 'aspiration' of tanks connected to atmosphere will the dessicant devices hold, and what happens when the dessicant (like the crystals in the useless bags sold to keep boats dry in winter) becomes saturated ? Will the devices needs drying out ? At what typical intervals for varying tank sizes.


Marine16 refer to 'drawing off accumulated water', so they seem to admit that their dessicant devices don't work.

The MSDS for Diesel Fuel Complete

DFC PDS (anodesdirect.co.uk)

refers to

"[DFC] Replaces the lubricity lost when the sulphur was removed " with the inherent implication that unless you use DFC you will have no lubricity in the diesel. A highly contentious statement and one that would send shivers down the spine of any tribologist.

Yes there is a need for products to improve storage of biodiesel by preventing degradation, but the puff and flammery of the press quotation really needs closer technical inspection.

 

[Dino]

I ended up with empty tanks at the end of last season and couldn’t fill them due to Covid lockdown. I was worried that I might have diesel problems this season but I had no issues. In fact, on my 2 week sea trip I never had to replace any primary fuel filters at all. The filters were all changed before the trip but no issues at sea whereas I had to change a few filters at sea two years ago and I had left her with full tanks.

 

[sarabande]

How about emptying the fuel tanks and waiting till barometric pressure is the median 1013 hectopascals or milliwhatsits, and then sealing the breather and fill so that no air (and hence atmospheric water) can enter or leave ? What will it take in terms of an air pressure change to collapse or explode a tanks ?

Or one could squirt nitrogen into the tank to displace the air, then put a bung in.

 

[Greg2]

Well we filled our tanks yesterday in readiness for lift out and included a good dose of Marine 16 so not much I can change now!

Interestingly, the chap operating the pump said that they now get a diesel with a mix that virtually eliminates any possibility of degradation / getting the bug and is cheaper for them to buy. He couldn’t provide any more detail so I can’t say what it was.
.

 

[Cheeky Girl]

Hi

I came across this just before I was thinking about filling up the tank

Winter-lay-up-to-fuel-or-not-to-fuel

What do people think?
Regards
Graham

 

[Wing Mark]

I intend to put a moderate amount of diesel in the tank and use the boat whenever the sun comes out.
If I end up putting my new(to me) boat ashore, then I shall empty the tank and check it's clean.
I'll put the fuel in some sealed cans for the winter.
Come spring, I'd rather have 10 litres of slightly suspect fuel than 50.

 

[Portofino]

Being doing it for years .
leaving very little in + bio cide shock dose and in season dosing as recommended.
Use a Agri biocide which is good and cheap as get through the farm business reckons to dose 25000 L so strong stuff .

Its easier to follow what they say on my boat with tank drain cocks and clear bowl racors .

Not sure how one would do it without……good luck with that !

Also stop cocked clear sight glasses ( actually plastic like the racor bowls ) are handy as I can see not only the levels but the colour and anything else , they start at the very bottom as well .

Its Med based but occasionally the air temps drop although water where it’s sat never drops below double figures .

I do ( outside Covid travel restrictions) start them + check them every couple of months throughout the winter anyhow , to circulate ALL fluids amongst other things .

Don’t like leaving any tank full as ………if it leaks unknown = less mess .

 

[Bilgediver]

Hi

I came across this just before I was thinking about filling up the tank

Winter-lay-up-to-fuel-or-not-to-fuel

What do people think?
Regards
Graham

This habit which I used to support was acceptable in the good old days. However I feel that if unless using white diesel there is no advantage due to what is happening to the E fuel regardless of the tank being full or empty and it may in fact be better to run down the fuel level pre layup and then fill up on re commissioning. The Red does not have the bio neither does some white but you need to check with your supplier to find out what is being supplied.

I certainly agree to those comments you found and mentioned.


Edited to correct the non deliberate mistake re Red and White

 

[lustyd]

Fill it up and leave it in the water, then use the boat as a boat. I've yet to see a fuel gauge on a yacht that would leave me confident in running down the tank in normal use, and the limits on fuel storage at home will mean you can't empty a tank unless you do run the fuel down first. Even transporting a reasonable quantity in your car could invalidate your insurance (potential unlimited fine and loss of licence) so I don't think there's as free of a choice as we all like to think there is.

 

[jdc]

I don't top up before hauling the boat out as fuel isn't as stable as it used to be so I prefer to fill in spring. But I don't empty it out either, just end the season with whatever (1/4 or 1/3 full?) is left.

The lack of stability is sometimes - and was in a post above - blamed on the addition of biofuel, but, while that certainly won't help, the more important factor has been the change over to ULSD which is word-wide, not just an EU thing. ULSD is not as stable as the old high Sulphur stuff (but's lots nicer in other ways). Hence red diesel won't help here as although FAME free it's still ULSD.

In my opinion, a lot of problems with fuel instability are blamed on bio-fuels and/or 'bug' when the cause is as likely to be old-fashioned chemistry. Loads of scholarly articles exist on ULSD.

 

[Oily Rag]

Does anyone know what others do with fuel tanks for critically important diesel gensets. For example, in hospitals?

 

[Mistroma]

I check the tank twice a year, pre-lifting and pre-launch or soon after if I can sit in settled conditions for a week.

I noticed a steady increase in contamination since 2012 as I moved from UK to warmer climes. The contamination has never looked like "bug" and always more like degradation products such as ashphaltines. I only add Marine16 pre-launch and just before lifting out. However, I always keep the filler o-ring well greased to prevent water ingress.

I used to leave the tank full over winter but changed to leaving it close to empty in 2018 (I think). I still get some residue at the bottom of the tank but have not noticed moisture or "bug". The 30 litres in the tank since Oct. 2019 was clear with about 1 litre of cloudy material near the sump and a teaspoon of dark oily material. No visible condensation on the tank wall.

I added some more Marine16 and test ran the engine which started immediately, not bad after almost 2 years storage.

I keep meaning to do a calculation to esimate the amount of moisture likely to enter the tank each winter. I remember someone claiming to have calculated it was about 5-10mls in a 200 litre tank but haven't repeated the calculation. I'd agree that it seems safer now to leave the tank almost empty over winter and that it is more important to seal the filler cap properly.

Surely Marine16 would advise people to keep a full tank and add plenty of Marine16 if they just wanted to boost business. Telling people to keep the tank almost empty would surely mean little or no Marine16 would be needed in winter.

 

[stuartwineberg]

I understood that the red diesel we use is specifically FAME free. thats what differentiates it from the standard B7 (7% biofuel) road diesel at the pumps. Has that changed?

 

[stuartwineberg]

This from MDL website. Note reference to FAME free

Watson is the preferred supplier of fuel used at MDL's marinas across the UK. MDL fuel stations offer high quality fuel which meets the new British standard and is FAME-free thus removing any headaches about long-term storage and low-sulphur.

and this from Cowes harbour
The Fuel Berth supplies Ultra Low Sulphur diesel fuel free from any biodiesel.

premier just say their diesel is “high quality” whatever the heck that means

sounds like marine 16 drumming up business although I do put it in at every fill

 

[Cavalierbond]

Was advised by one of the “ bros “ in the marina to use” aqua solve “
Has anybody ??

 

[Farmer Piles]

Currently got a petrol powered boat so can't comment on boat tanks. But, here on the farm we use nothing but red, Our combine harvester has a Tier 4, 9.5 litre Mercedes engine. We use it for about 200 engine hours per annum over about a month and then park it up for the year, it has an 800 litre tank. It doesn't seem to make any difference on how full we leave the tank for the intervening 11 months - same for the 1000 litre bowser that we drag around to fill each year. Both are plastic tanks. Never had any trouble and been doing this for decades.

 

[andy59]

I thought most marine diesel was Fame free, Princess wisely put sumps and drain cocks on the fuel tanks so fuel hygiene not a problem. Fuel levels all over the place through winter over last 6 years and not found a drop of water, don’t use additives either, works for me .

 

[stuartwineberg]

I thought most marine diesel was Fame free, Princess wisely put sumps and drain cocks on the fuel tanks so fuel hygiene not a problem. Fuel levels all over the place through winter over last 6 years and not found a drop of water, don’t use additives either, works for me .

Yep, see my post #16