"Custom" Bain-marie--Am I over my head?

[Temple Distilling]

Hello! My wife and I are just getting the wheels moving for our dream, and have concocted our "perfect still", however I am seeking wise council in this from anyone with more experience.

Our issue: We can't afford a boiler, but we do not want the risk/liability of open flame, and I worry about coming restrictions on this anyway for the future..

We want a nice looking still and love the alembic copper design versus a utilitarian type of still, and will be making gin (final run, no reflux needed). We have our eye set on a Portuguese alembic, and as I have been researching bain-marie systems, most use open flame anyway. My thought is to "set" the still in a larger diameter stainless tank, weld a top around it to the edge of the boiler (basically a sealed jacket at this point), and run electric elements to heat water and create steam around the base and sides of the boiler.

See my diagram, I figured the efficiency might be acceptable since the copper will conduct well, we can divert some steam during warm up into the charge, and play around with water levels to get optimum output without losing steam. We have connections to some great welders and some fabrication equipment, just not enough to concoct our own still from scratch. Thoughts?

[HedgeBird]

Seems like a reasonable way to go.

Welding stainless to copper is a massive pain in the ass even for great welders. You might be better off welding a copper flange to the still, and a stainless flange to the stainless tank and connecting these with a gasket.

Also look at filling the "jacket" you create with heat transfer fluid instead of water/steam. See this previous thread for lots of good info:

http://adiforums.com/index.php?showtopic=1786&hl=%2Bheat+%2Btransfer+%2Bfluid

[Pajo]

Check out southwestern distillery in Cornwall UK, Tarquin uses a Portuguese alembic fired by a gas burner he told me that as long as there is plenty of ventilation it works just fine - his gin is damn fine too. Also don't forget all cognac is distiller over an open flame.

[Silk City Distillers]

Suspect that the fabrication of a stainless jacket, associated flanging and modification of the still, supporting legs, plumbing, heating elements, and so on will cost at least as much as the still did, potentially more. Consider the risk that something goes horribly wrong. Nobody is going to be happy when the welder blows a big hole right through that still when trying to attach the flange. Not only do you need someone skilled in stainless fabrication, but copper fabrication as well. And let's face it, it would be a shame to see an alembic turned into some kind of frankenstein by a shade tree welder. Don't forget about the freight costs associated with shipping the still to and from the fabricator, this work will need to be done in a machine shop (this still is not precision, nor is it perfectly round).

Not trying to rain on your parade, but I suspect from a TCO perspective, ordering the still with steam coils installed and finding a good used boiler will probably save you money and sleepless nights.

At least ask the manufacturer if they can build what you are looking for, if anyone can do it, they probably can. At least if they screw up, it's on their dime, not yours.

What size still are you talking about here?

[Temple Distilling]

We are only looking at about 150 gallons, and the welding will be free but of course we will need to buy supplies. I greatly appreciate the input, that is why I decided to post this. What I had in mind I actually found a very similar setup in Scotland at Pickering's Gin

[HedgeBird]

If you just did heat transfer fluid, and not steam, would you even need an air-tight seal between the outside pot and inside kettle? My understanding is that oil and glycol type bain maries are not sealed and vent to the atmosphere. The only air/liquid seal you would need would be for the still drain that would have to pass through the jacket.

[Dehner Distillery]

I have transfer oil if you need some.