This is risky but I do from time to time form plexiglas. It's
thermoplastic - I hope that's the correct term, in any event it's
the kind of plastic which softens with heat, can be bent to shape
when hot, and retains the shape after it's cooled down again.
I use a blowtorch with a bushy broad flame, gently, from a distance,
to heat as evenly as possible the area I want to get soft, then bend
the soft hot plastic over a mandrel of the appropriate shape, then
when it's taken the shape spray it with water to cool it & freeze
the shape before it sags or some awkward motion of my own messes it
up. An assistant can be helpful.
As I said it's risky. Too much heat will bubble the plastic, a bit
more will set it on fire. Been there done that. You might want to
experiment with a few pieces of scrap to get a feel for how it