Cloudy diesel that clears in the med sun.

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smb

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I have been drawing water/fuel from the bottom of my tank today. After a cup or so of what was clearly water, I have taken the next c25 litres of fuel off the bottom and decanted it into clear poly bottles. After a while a little water (a drop or two) settles out, but the fuel is quite cloudy.

Following a search on here I found an old thread that said I should try warming it to see if it clears. An hour in the Med sun (Kalamata) and its cleared nicely, depositing some more water droplets in the bottom of the bottle.

Question is, if this fuel is holding water is it safe to continue using it and monitoring the water trap, or would it be better to draw out the remaining 130l and leave that in the sun litre by litre to dry? Other than fuel (mostly bought at sevice stations) nothing else has been added to the tank since 2008, when I stopped using starbrite bio diesel on the advice of the local bosch specialist who suggested it might have been responsible for my injector pump rusting and then seizing. Naturally I dont want that to happen again.

Steve
 
I suspect that your cloudy diesel will burn OK so long as there isn't enough water in it to stop the engine, ie it'll just turn to steam if there isn't so much. How much isn't so much I would hate to try to guess.

Leaving damp diesel in a fuel pump/system is not a thing I would do without weighing up how much it'll cost me for a new pump.

How to clean it up???

The easy, clean way is to drain it off and dispose of it.

If I was playing with a cloudy solvent in a lab I would mix it with a dessicant like anhydrous magnesium sulphate, leave it to settle and decant off the sparkly clear top layer of solvent. But you probably can't get that and it would take loads if you have loads of water.

Something that won't dissolve in diesel but will adsorbe water, like flour, or salt, (NOT SUGAR) could work, but it'll be messy, and it may take some settling to get it clear. Filtering 130L through coffee filter papers is going to take ages, but it's doable. Decanting 120L clear off the top and filtering (or throwing away) 10L is an option too.

Pumping it through a carbon water filter may remove the water, how much are they?

Have fun.
 
Cleaning

What worked for me in the past is this.
After the diesel tank I have fitted a Dahl water sep which includes a filter. (By the way is this the primary or secondary ? I keep forgeting).
So I bought a cheap 12V diesel pump and got a few plastic 20L empty containers.
I filled them with diesel that went through the Dahl water separator. I did it twice just to make sure. You have to remember to put the pipes of the separator in previous order.
 
I think thats halfway to a 'fuel polishing' setup.

gnatsis said:
What worked for me in the past is this.
After the diesel tank I have fitted a Dahl water sep which includes a filter. (By the way is this the primary or secondary ? I keep forgeting).
So I bought a cheap 12V diesel pump and got a few plastic 20L empty containers.
I filled them with diesel that went through the Dahl water separator. I did it twice just to make sure. You have to remember to put the pipes of the separator in previous order.
Click to expand...

I also get confused re primary/secondary As far as I am aware they are named in sequence from the tank so your Dahl is your primary filter, even though I view the secondary filter as the real main (primary?) defence against against contamination.

I like your idea though. My CAV primary has twin outlet ports, only one of which is in use. So Like you I could use an extra pump to draw fuel through the filter and back into the tank/containers.

In the meantime I have bought (and drank) some 5l clear poly water and wine containers and intend to fill them with fuel and leave them to clear in the sun as it seems to me the amount of water diesel can hold in suspension is temperature related.

So far the old md30 starts and runs fine, so I think I'll keep the meths/flour/salt/racor suggestions in reserve in case the solar treatment does not work, but thanks for the suggestions.


Steve
 
Just a note, temp will usually speed up a separation of two phases, but will also tend to increase the soluability of them, so your warm clear diesel may contain more water than cold diesel, but it won't be a big difference. I may as well have kept my gob shut then, but now you have a bit more info at least.
 
Water in diesel

I think the question is whether it is the warmth that causes the water to fall out of the fuel or just the standing still. I suspect more just the standing still. Anyway regardless I think the practical approach is to continue to remove fuel from the bottom of the tank. Allow it to stand (or warm up) then discard the bottom of the fuel in containers and put the top clean part back into the tank. Continue this process for as long as you have patience or until fuel is showing up with no water. Redo the clean out at regular intervals at least each season. I think also you should try a different biocide ie one considered suitable for diesel pumps.
IMHO you are right to drain fuel and many other owners should do this but don't. Well at least one local acquaintance who was stopped by bio mass (mess) bacteria.
good luck olewill
 
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