Err is that "without success" as in couldn't solder the joint, or
"without success" as in never got hot enough to allow the solder to
flow?

The solder not flowing. It was hot enough to get the flux fizzing away
merrily, though.

That would also indicate trying to work "wet" to me.

It was definitely totally drained down. I only soldered new sections of
pipe. The fact that the proper torch soldered it in seconds tends to support
this. The joint to the preexisting pipework was done with a compression ball
valve as there was no way to drain between the rising main and the
connection point.

I suspect the main difference is that the sort of torch I'm talking about is
even smaller than you imagine or had a wider nozzle. Or maybe it had started
to run out of gas without me noticing. It worked fine for 15mm, though. The
main problem I think was the width of the flame, making it difficult to
concentrate the heat in one area. I think, perhaps, the wide nozzle was the
feature most preventing me soldering it. Also, I was using a ceramic tile as
a heat mat. Maybe a proper reflective heat mat would have given that last
push to the temperature. It was obviously very close, but no cigar.

Christian.