Hi all,

I was reasonably happy with my process. My biodiesel was passing the 3/27 test comfortably. sometimes i make a little more soap than ideal suggesting perhaps that i need to dry my raw oil a bit better but I wash thoroughly and the final rinse water is clear.

Anyway i thought I'd try to polish my bio using a magnesium silicate powder for ultimate peace of mind, using about half the quantity needed for dry washing of unwashed bio. When I filter the final product I wasn't surprised to finish with the same clear, bright diesel that passes the 3/27 before the drywash process. However when I left the 1 um filter bag that i used to remove the drywash powder there is a strong smell of methanol from it. This suggests that despite thorough water washing there is still some methanol bound up in the bio.

I suppose my question is how much methanol is needed to create this smell. Are minute ammounts enough to cause a strong smell or could there be a bigger problem with my water wash? I tend to use tap water for convenience and I live in a fairly hard water area but I could use rainwater which would be softer and more 'absorbant' of contaminants?