Is it good prcatice to fill up fuel tanks despite not needing to?

Red diesel blended with Bio diesel fuel

OAF said:
since January this year red diesel now has a percentage of bio fuel in it, this will breakdown in your fuel tank after 3 months, there are addatives on the market that will prolong its shelf life, I use a product called exocet fuel save. I always keep my tanks full and most definetley make sure they are full to the brim in the winter, it saves the build up of condensation in the tank.
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Can you tell me ,is this blending throughout all red diesel production..across the EU..what percentage Bio to original diesel ? how long does the addatives extend the shelf life and what is the shelf life without additives..can you buy red diesel without Bio in it.....because Bio is cheaper is the blending process just to make more money for the supplier....because the to cost to the indvidual pleasure users having to clean there boat systems because the Bio content can go off , in the system over the winter period ,the cost to pleasure users is quite considerable....having been a marine engineer and i have the expereince of laying up boats for the winter and winterising engines both petrol and diesel..the extra cost to boat owners is considerable if they do not do the work themselves..also the waste of discarded fuel is considerable to
 
full tanks?

not sure about all this full tank business, A friend and me walked onto my Sealine 360 and unbelievably, i heard a motor click in, could,nt believe it but my auto bilge pump just started, on inspection,my starboard tank just decided to burst and diesel was upto the sumps already,panic started and i had to jam up the float switch to avoid filling Hull marina with diesel, It took lots of helpers and lots of plastic drums to stop disaster,Can,t imagine what would have happened if i was,nt around.
 
Diesel Spillage

How old is you Sealine 360 ? was it the tank that split or a fitting problem..my tank on my old MFV was 30 years old and held 600 gallons and was almost as strong as the day it was installed...
 
Diesel is supposed to have an average 5% bio content, this was chosen as a figure because of older vehicles had piping made from rubber, higher concentrations would rapidly deteriorate this, and other rubber components. Bio has a natural cleaning ability, higher concentrations will remove any debris within the injection system and it will rapidly collect and block the diesel filters and possibly the injection pump.

Bio content is going to rise, as older vehicles come off the road due to age, and these are replaced with vehicles which have the rubber components such as flexible fuel pipe and other seals which are bio tolerent, it will. No timescales have been set for this to happen yet.

People believe road and marine diesel are different, they are not, they are exactly the same apart from their stained colour, its cheaper to manufacturer one diesel in quantity and just add the red stain for tax free diesel.

Although the bio content should be 5% in reality it is currently only around 3% in Europe as the bio element is currently very expensive to manufacture, yet in other markets it can be as high as 7% or more. Remember the bio element is derived from plant or food crops and food prices have risen due to world shortages and fuel manufacturers have to compete with food processers and manufacturers to purchase it.

Additives abilities to deal with water and other contamination varies from make to make, the amount of contamination, and the tanks quantity of fuel, so there is no definate answer to this question other than peoples experience of such products.

Diesel does not go off, petrol does, petrol does not burn as it is its vapour which burns, it is this evaporation which degrades petrol quickly; diesel by contrast, is an oil which does not go off easily as it does not evaporate quickly.

The best advice is as follows:

Reduce the amount of water in your tank, most of it comes from condensation in the air, keeping the tank full before a lay up means virtually no air space, so little to no condensation.

Add a fuel additive, this contains components to reduce the effect of any condensation, which is very little with the tank full, and deal with the nasties such as diesel bug which will form with water.

Drain the tanks if a very prolonged lay up is enviseged, a normal winter lay up is not defined as a long lay up, over a year is accepted as the the beginning of a long lay up. Clean and drain the fuel lines, filters, and injection pump and blank them off.

Where spare diesel is contained in a sealed container such as a jerry can, and the can is full, there should be no problems and this can be stored for many years without issues as long as the fuel and fuel container are clean.
 
Winter Lay up Red Diesel/Bio

In the past we would not have cleaned pumps,injectors, ,fuel lines on a wintering shedule unless asked by the customer or the pump needed recalibrating and injectors reconditioning..the point here is we have a vegetable and mineral blended fuel in the past we did not,so it is the time scale of the vegetable content breaking down is rather critical..so (1) if exposure to air is going to make break down faster in the tanks they have to be topped up and full to the brim as before .... (2) but we have to know the breakdown time of the fuel in the fuel lines ,filters system and fuel delivery pump..because we have safety issue here as well....(3) this going to add considerable amount of man hours to each vessel for marine engineers
 
duesouth68 said:
How old is you Sealine 360 ? was it the tank that split or a fitting problem..my tank on my old MFV was 30 years old and held 600 gallons and was almost as strong as the day it was installed...
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yep 1994 did,nt expect that,alloy by the way and it was a hole in .
 
Tank problem

malc60 said:
yep 1994 did,nt expect that,alloy by the way and it was a hole in .
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If it is a split in the alloy then it might be a tank mounting problem the tank is to firm mounted on the hull structure the hull flex's even on a large vessel ..but if it is corrosion ,it be some form action of dissimilar metals
 
There is no definate breakdown time for the bio element as there are many factors to consider, and a large number of variables to consider.

On its own bio will begin to break down in around 6 weeks when exposed to water, or the condensation in a fuel tank, but this is extended with the additives in normal diesel at a 5% concentration. These additives and quantities vary from manufacturer to manufacturer, this makes it impossible to give a definate answer. What we know for certain is that full tanks reduce condensation, and that additive treated diesel using proprietery brands of aftermarket treatments means no problems for the average winter lay up of several months, for all fuel manufacturers.

From this perspective it is prudent or insurance that we fill tanks and add an additive, there will be no problems for several months.

If we begin to store diesel for over a year, even with additives, it begins to break down, then the variables come into play, different fuels react differently and is the reason for draining and capping the fuel system off. Some fuels may last for 18 months without deterioration, others will deteriorate badly, this is mainly due to the fuel manufacturers blend and the reaction with certain additives in the fuel. This is the reason many specialised application users are pressing for straight fuel, free of bio element, this includes hospitals for their emergency generators, and a number of military or other emergency users.
 
I cant add much more to this as Assassin has done a pretty good job explaining it, I can tell you what I have learned from my diesel suppliers, A little background first, One of my companies supplies red diesel or otherwise known as gas oil, 35 seconds, medium diesel, It is not the same as road diesel (white diesel) that has had the dye put in to it, however that sometimes happens, it depends where it has come from, the reality is this, you CAN NOT guarantee what you are buying from one supplier to the next, we all try and get the cheapest wholesale price which means that in many cases we will use several different suppliers, who in turn use different refineries who all have there own blends and methods of producing the red stuff.

I can only speak from experience of being in the marine industry for many years, My company also operates a hire fleet of boats and a very good friend of mine operates a much larger hire fleet of boats, he is now starting to see problems with some of the engines in his boats due to the fuel that he is using, Some refineries are supplying low sulphur diesel without the bio content but this wont be for much longer, I am fortunate that my company uses a supplier that supplies us with the low sulphur fuel (approx 5000 to 10000ltrs a week) and as yet we have not experienced any problems, this does not mean that we are taking any chances, we do not drain our fuel systems in the winter so this year WE WILL BE treating ALL of our boats when they are layed up,and yes we keep the tanks full.

My friend is experiencing problems with certain in line fuel injection pumps where the internal rubber seals are deteriorating because of the content of bio fuel, this is a serious problem and we have seen similar problems with some of our private customers boats this year where the engines are slightly older and the seals were probably in poor condition anyway but now the problem is exacerbated by the bio content in the fuel.

I now use a series of products called Exocet fuel additives, they do a range of additives for different circumstances, I am only a customer of theirs so have no interest in the company but this is their web site http://www.fastexocet.co.uk/

I often hear people saying "I never use any fuel additive,never drain my tank, never fill it in the winter, and have never had any problems" Great they are the lucky ones and good luck to them, I never take chances like that and for what it is worth on my own boat, (twin tanks) I keep them full all the time and keep them dosed with, Fuel set, and this winter they will be dosed with Exocet fuel store.

For the sake of 40 quid or so on additives inst it better to have peace of mind that come spring you will turn the key and know that your expensive throbbing beasts will be running on clean uncontaminated fuel oil and if you keep your tanks full you also have the peace of mind that you can set off cruising without firstly visiting the fuel barge, after all, diesel prices only go one way and that is up so it is also going to save you money by keeping them full prior to winter.

All of the above is purely my opinion of course.
 
Oaf

Thank you for your contribution, you have highlighted a couple of points worthy of mention.

First we are in an overlap period for the addition of bio element to certain diesels, and this will continue for the remainder of this year, after this bio will be added to all diesel fuels including 35 second diesel (gas oil).

This is fine for older engines, but not newer engines as manufacturers specify the quality of diesel used in them to meet current environmental specifications, this means diesel which meets that found in road vehicles. This is exactly the same as that sold by most marine fuel outlets, and is basically road diesel with red stain added.

Most major fuel suppliers actually confirm this on the technical sections of their numerous websites.

Good luck in finding cheaper wholesale suppliers.
 
As its difficult to fill to the brim on my boat, without taking the inspection cover off,I place a dustbin bag on the breather,providing it hasnt got a hole in the bag it always breathes the same air.You could then have the tank 1/2 full and it would breathe the same air.
 
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