Just when you think you've got the hang of it :(

[thewormman]

 Ok so I am filtering my bio into cubies to store and I notice in the top of one I did yesterday there is a sort of scum???



Hmm that's strange not noticed that before so put it through my filter stack again

Double J cloth -> Ceramic Molecular Sieve -> 2 layers of 1 micron filter sock

When I look at it again it is still there, so it is less than 1 micron.

Now I thought maybe it is the Coldflow I have put in this batch, I got 10 litres off someone second hand so maybe its contaminated. This is the first time I have used it. So I had 40 litres from the last batch I made that I have been running in the cars with no coldflow, so I had a look at that

Same stuff floating on the top arrgh



Whats going on? I did a 50/50 on the latest batch with the Coldflow and it looks ok



The only thing that is common to both is Bio boost that I put in, also bought from the same man second hand.

Has anyone else seen this? Is it something Bio Boost does?

Before someone says it I know less than 1 micron should not be a problem in my engine but it bugs me and I want to know what it is, it shouldn't be there.
Is it temp related as we have had 10C this week at night but I thought that would be ok.
Feedstock is Soya and Rapeseed 95% liquid 5% fats.

Ideas???

[Tony]

I'm sure a layer like that can form with oxidisation over time if it's not disturbed, but filtering should take care of it.  How long was the previous one stood, and was it in an airtight container?

[julianf]

I sometimes get a layer / skin on the top of my settling drums (205ltr) - almost as if dust has settled on them.

Ive seen the same in glasses of water, left out for a while.

Ive never considered being concerned by it (the stuff on the settling drums).

[BANDIT2]

I get that as well and don't worry myself over it [rightly or wrongly]

[thewormman]

I'm sure a layer like that can form with oxidisation over time if it's not disturbed, but filtering should take care of it.  How long was the previous one stood, and was it in an airtight container?

Yes it was filtered a couple of times and still there.

Previous one was stood for a week in a cubie that was filled to the top and screwed down tight.

Jim on VOD was saying its HMPEs but I thought the Coldflow took care of that, doesn't it?

Also I water wash and I thought that stopped them?