I can probably help ya with this. I need the particulars - size of
cylinder, what it's made of, how the joint is constructed and the type
of solder. You have a real email address for me.

al

 I don't have your answer, but having been involved with soldering,
and brazing of ductile metals, just the thought of a lead soldered seam
would scare me!!! Brazing the copper sheet would have been a step up,
and the so called 'phos-copper' rods like are used on air conditioning
systems today would have been my choice. Those brazing rods are a blend
of silver/brass/copper which when applied with the correct technique,
and proper temperature, form an almost indestinguishable copper to copper
bond. I just can't imagine how many early divers were jet propelled
to their death with a foot long burst slit in their tank. YIKES!!!!!
I would guess that with the ductile metals, the tanks would not fly
apart like todays aluminum tanks, but would simply tear along a slit
and remain pretty much in one piece.

Has anyone ever really thought about how inefficient it is from an
energy standpoint pumping todays pressures into our cylinders? You
can grasp the idea just looking at the horsepower rating of the compressor
motor at your local dive shop.