mhorowit wrote:
Somewhere I read about a welding exercise where the student built a
tube frame of some sort, pressurized it, checked for leaks, then
smashed it flat and rechecked for leaks.
I've looked thru my books but can't find it. Anyone recall where I can
find a description of the exercise? - Mike

Take a 6 inch pipe. Fishmouth one end with 45 degree bevels, then keep
cutting all the way through the pipe along those same angles. Do it
again. Weld a shrader valve into one of the pieces, then weld the
whole thing (4 pieces) together. Does it hold air? Good. Now squash
it flat. If it still holds air, you can weld pressure vessels for
nuclear applications.

I could have the details a little off on the fabrication, but that's
the general scheme of it.