Old diesel - dispose or reuse?

[Rivers & creeks]

The fuel tanks on new boat are both half full of diesel that does not appear to have the bug, or if it does, it's a mild case at present (thanks for the help on a previous thread with that). But on that thread there were some dire warnings about what might have happened to the diesel in the 26 months it has been there! Although we are talking about a huge amount of the stuff - 75 gallons approx - I would still rather loose it than damage the engine or cause maintenance headaches. But is there a good way to use? How would I filter it and make sure it's good to go back? Are we taking filter through a fuel filter or through a muslin over a barrel? BTW, I will be emptying and cleaning the tanks. Thanks for your help. Simon

 

[Searush]

A lot depends on where you sail in my view. I'm no expert but I don't see "damage" to your engine so much as blocked filters & possibly injectors if the filters aren't there or aren't working or bypassed. This will stop you dead in the water & I don't think you have sails to get you home so you would then need to clean stuff up yourself (can be hard at sea, esp if in rough water) or calling Sea Start (if you are in their service area). If on a river, at least you can get ashore & summon help.

Others on other threads have suggested that you let it settle & skim the fuel off the top, it can then be used, possibly mixed with fresh fuel, or added to a car tank - where clogged filters won't leave you all at sea.

 

[vyv_cox]

The life of diesel fuel is considerable, assuming it to be in a tank with a lid. Provided it has not been contaminated it will be perfectly OK. I left my old VW diesel van standing with a fairly full tank for seven years when working abroad. It started immediately on my return and ran faultlessly thereafter.

Transferring it to a drum to clean the tank will give you an opportunity to check for water contamination, which can be separated out easily. Otherwise I would rely on the boat's own filters, trying a short voyage at first until you are confident.

 

[PCUK]

Why do you think it has any 'bug' contamination?

 

[Rivers & creeks]

Small discolouration and and what might have been sign of bug contamination but hard to say definitively. It wasn't obvious and from the previous thread I would have been able to spot bad contamination.

 

[Rivers & creeks]

Would pumping it through an in-line fuel filter be the best and most practical method of filtration?

 

[penfold]

Diesel does darken with age. As a marine engineer I get fuel samples(250ml bottles) everytime we refuel. These are required to be kept for 2 years; when the 2 years are up, they get tipped in the waste tank to make space in the sample locker. With a few exceptions the old stuff is a lot darker(and in odd cases cloudier with cruddy looking sediment).

Would pumping it through an in-line fuel filter be the best and most practical method of filtration?

fuel polishing (posh name for filtering your fuel) is a good idea even if your fuel appears clean to the naked eye. There are several threads about building your own portable or built in fuel polishing kit on here somewhere.

 

[nimbusgb]

Strikes me tha with 75 gallons of the stuff it would be worth calling in a mobile fuel polishing service and having them run a cycle on the lot. Top off the tank with fresh and Bob's your auntie!

Disposing of 75 gallons of diesel would be a bit of a pain unless you told a few raggies that it was going for free!

 

[sarabande]

Is this one of those "do it right, and it will be off the worry list for the next five years" jobs ?

If you have time, I'd pump it out to some 25 l containers (Amazon LVM 12v pump is excellent piece of kit BTW), clean the tanks, drain them, new filters, etc, etc.

Take the diesel in the cans ashore and shock dose them with diesel bug stuff, leave for a couple of weeks, then decant into new clean containers through a very fine filter, or make up one using a cheap imitation chamois leather from Lidl / Aldi.


That will give you 74.9 litres of clean, bug free fuel for the future, and clean tanks and filters. Big worry off the mind