Originally Posted by dracothered
I think the hardest part would be knowing what shape to cut the peaces of metal before shaping them.
ok heres a technique I use a sheet of paper reacts much like steel if you try an bend it , it will show you were it wants to stretch an also where it needs shrunk , cut your proposed shape in paper first seal with tape an use air pressure to gently inflate it it will show you almost exactly what will happen when you try to use steel or aluminum , doing things this way will keep costs down so you dont have to scrap all the failed attempts an keep buying metal as well as you will learn what shape the metal will have to have to get your desiered shape. that being said , if I were to form a tank , I prefer to use slightly lighter gauge steel than say 16 gauge do a test run with air pressure as you can hook up an control the pressure from a distance that would be how ever long your air hose is , once you get a decent one that way move up to the hydroform . the key to this is slow an methodical but worth it in the end . I have tried it didnt like it much .
personally I prefer to hand form on a english wheel then use different hot an cold techniques , as well as hammer an dolly to get the final result . ya just have more control over the metal my way .if anyone would like to see some pics I built the tanks on threads mock up kinda rough , build no.2 wifes beach trike , an , felt guilty been holding out on one build . all done with hand forming techniques.