Help with Condenser Design for 100mm/4" Boka Column

[Shyysiryxius]

Hi All,

This is my first still build and a mate and I are building one each. He for reasons i am not sure about has opted to just go ahead and build a 4" column. We have obtained 6m of 4" copper pipe from a wholesaler in his family so we are set to begin construction.

We will be using standard SS beer kegs as a boiler with a 4" flange ferrule welded to the top.

My question is what diameter tube should I use for the condenser. I really want to try as much as possible to just follow the original Boka still design here:

viewtopic.php?t=36050

which states 1/4" is ideal. Once I have some experience under my belt I can look at other designs. My mate keeps thinking up wild ideas of a condenser and such and tbh I think he's just going to waste his time and his $$$ until he knows what actually works and how it works.

Anyway, since he was set on 100mm im stuck with this size column. I will be using a water pump to get water re-circulated and it works great on my current Alcoengine Reflux still.

Im left wondering if 1/4 is still the way to go as the amount of rings ill need to do around the original coil will be significant if I am to fill up the entire 100mm diameter. I read the 2x helix is a good starting point (for 50mm column) but for my 100mm column this would leave a lot of empty space for vapor to escape. Thus I reckon i'll end up with a 12x-14x helix to fill the void if I go that route.

That many wraps x say 6" depth will be a significant amount of copper. What is everyones thoughts about the best way for me to tackle this? is 3/8" a better approach and do some 6-8 coil wraps?

Cheers!