Sharon Osborn at BLOC-WERX in South San Francisco CA posts a very lucid note 
about B/R stills (which several other people seem to be using also).

A number of laboratories I'm familiar with distill xylene and the aliphatic 
xylene substitutes (such as Clear-Rite 3) using the B/R spinning-band still. 
Only the cytotechnologists seem displeased with the quality of the product, 
and I frankly don't understand why. 

B/R has protocols for distilling the different aliphatic products, which are 
NOT interchangeable with each other. If your lab manager wants to change 
brands on you with every phase of the moon, then distillation isn't for you. 
As far as I know, you cannot distill limonene (Ameri-Clear etc.) and other 
terpenes.

I have not encountered a lab that distilled alcohol. The physical chemistry 
of the situation dictates that what you get back is 95% alcohol, so you still 
have to buy absolute alcohol, and the process is thus inherently less 
efficient.

I have no experience with the formaldehyde still, and that's what I'd like to 
know more about. In my experience, assaying the formaldehyde and mixing the 
buffer salts would be beyond the skills of most laboratories (I NEVER saw a 
lab prepare neutral buffered formalin correctly). The only way I can imagine 
this being practical is with kits of pre-mixed buffer phosphates, and I've 
been surprised that nobody ever made these available. Are they available now?

Bob Richmond
Samurai Pathologist
Knoxville TN