Filtering grey diesel. initial trial.

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pcatterall

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I have posted before about grey coloured diesel suddenly occurring in my tank.
I've had mucky diesel before but it has always cleared after several passes through my polishing system ( using 8 micron filters).
Also when last to stand it has cleared over time.
This grey colour is quite new and possibly results in additives doing the trick but leaving very fine particles I suspension. I wrote to the additive manufacture
and got comprehensive replies the main message was that these particles are so fine that they will pass through the injectors and engine without harm.
There is no impact on the grey colour after several passes through the polisher nor after standing for several weeks. ( The fuel is Spanish road diesel).

I am proposing to give the tanks a really good clean but would also like to understand these 'grey' particles better. I'm considering buying some paper laboratory filters
going down to a very fine filter ( 1 Micron?) and testing the diesel in the tank. If I can get one to work then I can consider cleaning the 40 gallons in that tank or perhaps if
the particles are very fine just use it without worrying ( engine is a Perkins 4108)

I will be grateful for any suggestions on this and any specific ideas about getting hold of laboratory type filters.

Just wondering now if Laboratory filter paper is readily available at say 2 Micron as I cant find it after a quick squint online. I guess that if the particles pass through 2 micron paper they should not cause issues in the 4108?
Worth mentioning that the original reason for the additives was excess hard tar ( seen) developing on the dipstick. The additive seemed to reduce this but made the fuel grey.
 
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I've seen something like your grey diesel before. I put it down to waxing but was never sure. All I knew was that it blocked a normal CAV filter after about 20l. Heating it might work.
 
You can get 1 micron filter elements to fit the 10 inch housing widely used in water purifiers.
AIUI some of these are OK with diesel but DYOR.
Also some of the engine oil filter systems which are fitted to trucks go down to below 2 microns.

Do you have copper or brass plumbing in your fuel system?
 
I thought a 4108 would run on chipshop oil and pondwater as long as you strained the tadpoles out with a teatowel?
If you were talking about a modern common rail diesel all that might be necessary but for an old perkins?
 
savageseadog said:
I've seen something like your grey diesel before. I put it down to waxing but was never sure. All I knew was that it blocked a normal CAV filter after about 20l. Heating it might work.
Click to expand...

savageseadog said:
It's the filter that's the problem
Click to expand...

No it isn't, he's ran it through the polisher several times and the filters haven't touched it.
 
In fuel filter testing most specs use lab filter membranes to check efficiency .these are 0.45 micron made by a company called sartorius
but you will need vacuum assistance to pull a sample through the membrane.
 
pcatterall said:
I hope my tests with some fine filter medium will 'clarify' matters!
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Have you tied getting a sample into a clean bottle? Not exactly a scientific test, but you could do things like shine a light into it to observe the cloudiness, leave it a while to settle, cool it (e.g. in fridge) and see what you can see. If not scientific it is at least cheap.
 
lpdsn said:
Have you tied getting a sample into a clean bottle? Not exactly a scientific test, but you could do things like shine a light into it to observe the cloudiness, leave it a while to settle, cool it (e.g. in fridge) and see what you can see. If not scientific it is at least cheap.
Click to expand...

I have tried this in a tall clear container over 2 weeks. With a good light and white paper behind. There was no difference in opacity observed at different levels.
 
pcatterall said:
I have tried this in a tall clear container over 2 weeks. With a good light and white paper behind. There was no difference in opacity observed at different levels.
Click to expand...

OK. Any merit in trying additives on your test sample to see if they make any difference?
 
Sandy said:
If you have a child at school have a chat with the chemistry teacher they might have some.
Click to expand...

You could also try coffee machine filters, or try your friendly local pub landlord, they used to use fine paper filter to return
Drips back into the barrels, but it been a long time since I lived in a pub !
 
Thanks for all your suggestions.
1) good point.... I will set up a test when back aboard and add treatment to a sample.
2) thanks..... I will contact diesel16 again. They did give me advice before but the problem is still there.
3) thanks...... I will bring a sample home and see if it can be tested.

Current thinking is that the early treatment removed the hard tarry deposit from the dipstick ( and thus I guess from the tank sides)
if that is so then deposits should, at least, not gum up my injectors and engine parts... so provided the physical size of the particles
can pass through the injectors things should be ok?..............................or am I dreaming?

Is it possible to get a finer filter to use in my CAV filter body that I use for polishing?

Thanks again
 
pcatterall said:
Thanks for all your suggestions.
1) good point.... I will set up a test when back aboard and add treatment to a sample.
2) thanks..... I will contact diesel16 again. They did give me advice before but the problem is still there.
3) thanks...... I will bring a sample home and see if it can be tested.

Current thinking is that the early treatment removed the hard tarry deposit from the dipstick ( and thus I guess from the tank sides)
if that is so then deposits should, at least, not gum up my injectors and engine parts... so provided the physical size of the particles
can pass through the injectors things should be ok?..............................or am I dreaming?

Is it possible to get a finer filter to use in my CAV filter body that I use for polishing?

Thanks again
Click to expand...

If you've already passed the fuel several times through your polishing kit, there'll be nothing left which would cause a problem to your engine. So just get on and use it!
 
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