As a once time Palmer Johnson ship fitter in the 'Hull' department working off of a traveling scissors jack platform [called an Ape], I imposed my will on unwilling 4 or 6 mm aluminum shell plate, bending the flat plate to conform to the compound curves of frames and stringers. [some times the shell plates are 12 foot long and 4 foot wide and are scribed with butt lines, water lines, frame lines that need to be matched up to the already welded in companion shell plates.]
It's easy, tack a new sheet on in one place and find an edge to set this plate on. Then weld on a dog to an already welded plate [the dog hangs over the edge of the new shell plate] and use a five pound mall to drive an aluminum wedge between the dog and the new sheet plate, thus forcing the new sheet into a firm contact with the frame or stringer behind the new shell plate. Once 'home' tac weld the new shell plate in. The welders will come in behind you later that night and cut/grind a VEE cut grove between the old plate and the new plate and fill that groove with weld plus weld the plate to the frames and stringers. You should be able to hang 3 to 4 plates in a 10 hour day with a 20 minute lunch and 2-10 minute breaks. Since the boat shrinks with welding, a few months later the weld is cut open, jacked apart, and re welded. The boats are welded over again about 3 to 4 times...or until the mm's match what's on the drawing.
These Boats Are Beyond Perfection.
You can do that...skip.