View Full Version : advise needed on BD quality

5th March 2009, 10:20 AM
:eek:I have been making BD for about a year and the troopy has done about 30000kms on BD. Have been having problems when I get on the freeway, after driving about 500kms, when I get blockage in the filter with light coloured flake crap. There is no water in the water seperator and I cant imagine that the crap would be residual catalyst, as it is washed four times as follows....
I wash the BD four times over two/ three days, and when the BD is crystal clear and the wash water is nearly clear and the same pH as out of the tap, I pump it to a tank to settle for about a week before I use it.

There seems to be a link between the blockages and the 4-5 hours continous drive at 110km/hr, because it has never happened with general about town drive.

ANY ANSWERS??:confused:

5th March 2009, 10:31 AM
I doubt that your bio is "crystal clear" after washing it with water. However you say you decant the fuel and let it settle in a drum for a week or so. Is this with the lid off and out in the sun and wind? Or is it settling in closed containers? If so, then the residual water will still be in the fuel, or at least in the bottom of the container. If it is settled inside a shed etc., then you need a heat source and a wind source passing over the open drums to allow drying. Water in fuel will cause a breakdown of bio and resultant clogging of filters with rusty looking stuff.

5th March 2009, 08:48 PM
Thanks Yorta,
I will try the aerator and fan in my storage tank. However, I just drained., 1 litre from tank of 800 litres BD and left it all day in a clear container and it clear as a bell, with no sediment or water in the bottom at all. So there is no water in the 800 litres and I have drained my fuel tanks and there is no water in there at all and none in the water separator.
I reckon there is a link with, the temperature after driving 500km at 110km/hr, and the white clugg clogging the filter????

5th March 2009, 10:34 PM
white clugg clogging the filter????

Sounds to me like high melting point bio.
What is your feed stock?
Does this white crud melt away to bio with a little heat application?

As for being residual catylist, no way as it would all come out in the first and or second washes.

6th March 2009, 09:51 AM
Yes, it does now appear to me to be as Qwarla says - high melting point bio. I wasn't at first sure of what you meant by "ight coloured flake crap", but now see that it isn't rusty looking stuff, but (as you say) "white clugg".

Tony From West Oz
7th March 2009, 03:06 AM
While I would normally agree with this diagnosis, the fact that it only is evident during long runs would tend to indicate that HMP (High Melting Point) biodiesel is not the source of this blockage.

There seems to be a link between the blockages and the 4-5 hours continuous drive at 110km/hr, because it has never happened with general about town drive.
After a 1 hour run, the temperature of the fuel in the tank of a normal, return line fuel system, would have increased significantly .
Can you provide more information on the oil used to make the biodiesel? Is there a significant amount of solidified oil in it when cold?
Please chill a sample of your biodiesel in the fridge and advise us if there is white stuff in your sample when the biodiesel is cold.

Please let us know about your "long trips" - were they taken during cooler weather or at a cool time of day? Cooler weather and HMP biodiesel may cause this issue.

The answers to these questions may assist in correctly diagnosing this problem.


Tony From West Oz
8th March 2009, 01:21 AM
Were you able to determine what the flakes were?

8th March 2009, 08:29 PM
:rolleyes: I have done the experiments:
1. Sealed BD in fridge for 6hrs. When removed, BD temp is 5 degreesC, and has significant amount of white flakes, about 3mm diameter.

2. Heated the BD and white flakes dissappeared. Crystal clear again.

Note: the white flakes in filter after long run are probably 10 times as big, as the 3mm flakes in fridge sample.

Thanks all,

8th March 2009, 08:54 PM
Its prob the dodgy oil supply some bloke handed over to you....:D:D:D

9th March 2009, 08:49 PM
:pHaha Nick,
your just jealous your not living in sydney anymore. Wish I could get out of here!
No, I think my oil is ok. it is mostly pretty clear and no solids. Still no idea what the solution is here......


Tony From West Oz
9th March 2009, 11:35 PM
Can you collect samples of your filter blocking "white flakes" and perform sopme tests on it?
I would like to see whether it melts when heated & at what temperature this happens.
I would also like to see if it burns when placed on a piece of paper and the paper is ignited. If it burns, does it splatter, does flame change colour?

Perhaps we can identify the substance.


23rd March 2009, 12:16 PM
Gday Tony,
I have tested the white substance.
I placed some on tissue paper and lit the paper. The flame burned around the substance and the substance melted, with no splatter. Eventually the lot burned. The substance appears to behave like a wax.
I put some on the stove and it melted at around 40 deg. C. And when cooled, the substance did not re- solidify. So, the heat did change it's chemistry.

I have added 'fuel doctor' to 200 litres of my BD, and there has not been any blockage on two long runs,(2x 600km). The 'fuel doctor',(fueldoctors.com.au), label says, "formulated to dissolve, disperse and prevent the accumulation of gum, wax, varnish, condensation and fuel bugs....".
Even though there has been no blockage, when I removed the filter, it was caked with the wax, on the top and bottom of the filter, and had not clogged the filter paper, like before I had used 'fuel doctor'.

If we cant solve this problem I might contact fuel doctor and try to work out where this 'wax' comes from. In the mean time I will continue using the fuel doctor. I wonder what the 'fuel doctor' actually is??? I came across it at a truck supplies in Sydney. Others such as repco havent heard of it.

Thanks again, for your help.

24th March 2010, 12:45 PM
Happy new year all. Its been a bloody year and still have the blocked filters.
:eek:OK, so its WAX:cool:.
Does anyone recommend a heater before the filter to dissolve the wax???

24th March 2010, 01:41 PM
Hi Jedrock,

Just a quick question, when you checked your BD for flake formation in the fridge etc, did you use BD from your vehicle tank or from your storage containers?

The reason I ask is that one of them may have a contaminant in them.

Is it worth making a new batch of fuel and storing it in a completly different drum/s? to elimante all variables though you would need to flush your fuel system prior to using the newly stored fuel.

probably a massive stuff around, but I thought it worth comment.

27th March 2010, 02:35 PM
Jedrock hi

hows your fuel problem ? I used to have a similar problem in a metal storage tank after a cold snap. I use oil with alot of animal fats in it (chicken i think) what would happen was i would get white gung sticking to the metal container and with clear bio in the middle. From how you decribe is sound almost the same. This possibly it happening in your fuel tank and after a long trip the fuel gets hot enough to melt and then goes into your filter and when it cools turns into white gung again. I got around this problem by fitting a light bulb in the water trap as a heater and changing the way i process my bio. I now use a 2 stage process and never have a problem with fats in the oil.

29th March 2010, 09:11 AM
Gday all,
Firstly Captaincademan, I got sample from storage container, which are the 1000 litre pallet tanks. I wash out the tank with every so often with new BD, when empty.
Secondly, Smithw, I am sure I have wax problem, and am not sure if it same as yours. The wax build up happens same in summer and winter. The only variation I have had, is when I add 50mls of 'fuel doctor', it slows wax build up down, but still the filters end up blocked. Also, when I add 'fuel doctor', the wax seems to collect more at the metal top of the cartridge filter instead of around the paper filter. So it looks like the 'fuel doctor' does, (as promised), dissolve fuel wax, but not enough to go through filter. I have also added 100mls per 75 litre tank with similar results.
So, I think I need some heat or I might try another product called, 'star tron' which also promises to get BD through filters.


1st April 2010, 01:49 AM

long time no hear...
I strongly recommend a helton fuel heater i've been using one for ages and never have to worry about filter clogs since.

13th June 2011, 08:13 PM

long time no hear...
I strongly recommend a helton fuel heater i've been using one for ages and never have to worry about filter clogs since.
I was just going to say the same as Nick. A heat exchanger should melt your wax.

15th June 2011, 07:33 AM
:eek:Gday all,
I have had a helton heat exchanger fitted for about a year. Has reduced the wax build up, however, to completely solve the problem, I think another heat source needs to be in the filter itself.