have tried sand, and dot 5 brake fluid. dot 5 works good for sfrole, but when i needed higher for the good stuff I had to go direct to the hotplate. kinda a bitch with a rb flask, just wrapped a bunch of AL foil around bottom and keep the flask about 1/4" form the plate. worked like a charm, left the hot plate on 10 the whole time, i think it might be a problem if plate was to cycle on and off at a lower setting. was able to distill real high bp oil under vac real quick. Dot 5 is real messy! I'm gonna try some silica sand and see what happens, last time i think I had it too thick. and was using regular sand, took 2 hours just to get hot and then never got hot enough to get sassy done. Any comments about sand.