Quote Originally Posted by tillyfromparadise View Post
You will need to ask the people who use ASM why they use ASM. I am sure they have a reason
Hi Tilly,

Firstly, you were correct in that the new oil I tested was rape-seed oil.

I use both sodium and potassium for processing. I buy the sodium from our local hardware chain (called Wilkos), who sell it packaged as drain cleaner, and it costs around 2 for 500g. I've always had difficulty getting the stuff to fully dissolve in methanol, and however long I leave it and however much I agitate it there always seems to be an amount that remains undisolved. I asked Dave about this the last time I saw him, and he suggested that it could be that the sodium packaged and sold as drain cleaner in the hardware stores contains some insoluble impurities, which seems a reasonable explanation. In any case, it still works when I add the resultant methoxide to my processor.

Turning to the question I asked you - (why do people use ASM) - I think that its easy disolvability is one of the main reasons. If you look at this link (http://www.biopowered.co.uk/wiki/Anh...dium_methylate) which is from the Biopowered Wiki page, the advantaged and disadvantages are listed as follows:

The pros and cons of using anhydrous sodium methylate
Mixing it with methanol is as easy as making orange squash
Being a liquid, there is no corrosive dust to worry about
Being around 70% methanol, using methylate requires less methanol in the batch
Methylate is considerably more expensive than solid catalysts although this can be offset against methanol savings
Availability is still an issue although this is improving

The "pros" do not list increased yield / conversion or decreased soap production as advantages, although I do seem to think that I have read users report that this is the case.

I have used ASM before, and I have recently bought some more because I did like it, if only for the ease of mixing. It certainly is more expensive, but it is convenient and a time saver. I'd reserve judgement on whether it results in a "better" process than methoxide made using the standard sodium crystals.

Best wishes,