I'm hankering for the better flow (which will permit better valves) of a bottling tank, but can't justify dropping the $1000+ for one. I have several legitimately acquired stainless beer kegs of different sizes, and access to a local skilled welder who can do SS no problem (I know it's not elementary welding). I'm picturing one keg inside the other on a small riser. Is a bottling tank anything more than one vessel sitting inside a larger vessel with:
  1. A fill and a drain fitting in the outer vessel,
  2. an immersion heater element in the gap between the floors of the inner and outer vessels, and
  3. a welded fitting through the outer shell allowing you to drain the inner vessel through a threaded fitting for the gate/valve?

And a lid. I know some will have paddles for agitating the honey or other fancy geegaws, but I don't need that.