[Stoves] Vegetable oil or biodiesel?

[Crispin Pemberton-Pigott]

Dear Richard

I think if you want to make a fuel you will have to avoid saponification and
I had not given it any thought, but if you add the lye directly to the oil
it will turn some of it into soap immediately so they must have a method of
keeping it pretty thin to avoid that.

I don't think soap burns, certainly not easily. Too much water in it. 

I know that heating veg oil an simply keeping it hot for a while causes a
shortening of the chains. I think that is the poor man's treatment. Used
cooking oil has a much lower viscosity than fresh oil, especially compared
with cold pressed oil. There is no reason it could not be used as a stove
fuel after 'desiccation by heat'.

Regards
Crispin



Thanks for that Crispin,

Re used veggie oil for the slow running single lung 5 to 8hp diesels, you
are right on:  In thinking abit about it, indeed soap is otherwise made from
lye/ caustic soda/ and tallow.
Wonder how it would do in the faster running diesels eh ?

Will revert from Lushoto (TZ) next week. 

Richard