I’ve been having trouble getting enough botanicals into my 2” pot still column for decent vapour infusion batches, so the 4” pot config is going to have a dedicated 8” basket. By putting a triclamp sight glass in it, I’ll also be able to use it as a fill port for running back to back runs without taking down the head – once I get my boiler drain, that is! It will also work as a boil ball for stripping foaming washes like malt or rum – the slower vapour speed in the ball should help bubbles collapse and fall back down the column, and the sight glass will let me see it happening.

I did all my brazing for it this weekend. There’s a bit of touching up of the soldering and I need to buy a lens for the sight glass, but the bulk of the work is done.

The starting point was an 8” copper sphere, 10cm of 4” copper pipe, a couple of triclamp flanges modified on the lathe to fit the pipe, and a 2.5” triclamp flange to use as the sight glass.

Firstly I sanded the 4” stainless flanges to rough them up a bit, fluxed them well, and then seated them on the pipe. you’ll note I didn’t clean the copper – I’m finding it easier to keep the Silfos 15 solder I’m using from running all over it this way.

After brazing with the oxy acetylene torch it was predictably ugly…

But it cleaned up nicely:

And then I split it on the bandsaw. I joined both ferrules on first to save doing the heat up of the workpiece twice.

Starting to take shape…

Sorry for the shoddy photo – it’s important to drill a hole in a sphere before heating it, otherwise it will be pressurised.

The heat I needed for my Silfos 15 rods was unfortunately such that the soft soldered seam in the centre of the ball melted and parted, Which actually worked out pretty well for me as I could use a hole saw to open the column ports while it was in half – much easier than trying to hold a sphere securely. these are tidied up with a half-round file later – couldn’t find the bloody die grinder!

I then filed and sanded off the original soft solder in the sphere seam, and rebrazed the sphere together with Silfos. I made a bit of a mistake here, I didn’t account for the thinner wall of the sphere relative to the pipe, and used way, way too big a torch tip. Too much heat meant a messy seam.

Right, sphere complete so time to put that sight glass on. After the seam experience I didn’t fancy brazing stainless straight to such thin walled copper, so I put a very short length of copper pipe on the ferrule first:

Then it was brazing time again:

After a bit of cleanup:

After a lot more cleanup:

Still some solder cleanup to do on the centre seam and around the sight glass port that I can’t reach with any tools, so I guess I’ll have to do it by hand… Sigh… No one will ever call my metalwork pretty, but I was glad to get it all done in a day! Also still to come is a stainless mesh screen in the bottom for the botanicals to rest on.