I tested a double boiler one time with straight water and had a couple of issues with it. The setup was a 55 gallon drum (cut down to about 40 gallons) with a 15 gallon keg inside, propane burner underneath. It worked, but all the steam became a nuisance inside the garage. It also seemed to lack decent heat transfer and I had a slow time stripping once the alcohol content in the mash started dropping (so it seemed). I ended up switching to oil bath in the same setup. I fashioned a stirrer for the oil which helps to keep the oil evenly heated, and I also have fashioned an agitator for the mash inside the keg. This setup does a good job stripping but the heat up time is still about three hours. The still starts refluxing when the oil gets to about 235 degrees. The oil tops out at about 245 at the end of the run. I'm not suggesting anyone do it this way, just offer it as an example. I have worked out a safety routine, learnt from a couple of interesting events. When handled properly, it's a pretty sturdy setup and is working well. If I had a magic wand though I'd go with steam. I did some shopping on Ebay for used natural gas heated kettles, used in food service, seems like they could be converted nicely into a stripping still, a few bucks though.
--- In Distillers@yahoogroups.com, "stillyaakman" <stillyaakman@...> wrote:
> Does any one have experience with water jacketed boilers? I, specieficly, am thinking about using propelene glycol to raise the boiling point to get a good temterture differential between the substrate and the heat source without scorching issues. Haven't done any searches yet but if anyone has experience along this line I'd appreciate some sharing. I'm wondering about boiling point/concentration relationship. If I need to think about condensing proplene glycol vapors. If the water jacket should be open to atmosphere or a low pressure (maybe 5 psi.) system.
> Thanks for any input. Dan