Sounds like good advice; perhaps I need a better glove too - the leather is reasonably thick, which is good because I've tried to burn it several times but also bad as I'm struggling for dexterity.
The last episode was 'challenging'. I welded on a bottom-draining nipple, but after later moving the heavy tank (using the nipple as a handle...) I noticed a big crack had formed; my weld was far too thin and not strong enough mechanically, though it had been leak free before then. In the ensuing 'repair' I then burnt a big hole in the base of my tank to one side of the nipple

- certainly got a lot of practice feeding the rods to build that up again; the underside looks like a bumpy mountain now
I got there in the end but needed to do a lot of grinding inside and then re-weld bits to fill in some inclusions - inside at the bottom of the tank which I can barely reach, let alone get gloved hands torch and rod into. I managed it eventually, though a 90min boil on Sunday has revealed a couple of small pits that I will need to re-do so the gymnastics aren't over yet
On a related note: I'm probably not going to bother grinding the huge uneven, bumpy weld under the pot - potentially revealing more inclusions/weaknesses. But in the absesnce of pickling paste is there any household (or brewshed) acid or other potion that will remove the blueing - or in my case almost browning in parts?
Cheers
Kev