Internal water pressure expansion of metal

[archimedes]

hi Ian,

good thoughts on the mold process, but referring back to the motorcycle
article for the mufflers, the gentleman duplicated the very same process
as described in one of the earlier posts regarding 2 stroke expansion
chambers. he created his shapes in sheet steel, bent the perimeter,
applied an entry & stop loss point; welding the 2 halves together
& then applying the necessary water apparatus to pressurized the
vessel. as the vessel's water content expanded the circumference
he initiated some deft hammer blows to begin removing the dimples
& to even out the surfaces. some great photography details
delineated quite well, each step of his process. i almost want to
dig the article out of storage just to reread the abstract.

would also like to add a thumbs up to your unequivocal dissertation to
the thermodynamic characteristics of heat, pressure & metal when involved
in such a process as described. i enjoyed reading your essays & got
a lot from them. you wrote clearly & i was able to follow with just
as much success. glad you stuck thru the mess & didn't give up.

hope to see more of your contributions in the future.