how do i reshape plexiglass into a dome shape? its the front screen for an old diving helmet costume.?

im trying to make a clear dome for an old diving helmet. just has to appear, not actually work.

The way is to slump it. Get some plywood, make two sheets with a hole about the right diameter for the job, place the sheet of plexiglass between the ply sheets and clamp it in place with spring clamps. Place the sandwich in an oven at about 150-160 C, and in a few minutes the plastic should start to slump through the hole. When its right (and you only get one chance), remove from the oven QUICKLY. Steve
orksecurity8 years ago
Heat would probably work -- but maintaining a smooth surface and even thickness could be difficult. I'd worry that you'd have to re-polish the surface, and that the view through it would be somewhat distorted. Suggestion: Buy a large plastic salad bowl and cut out an appropriate section from the side? (Actually, I believe the old hard-helmet suits didn't use curved glass -- just smallish windows of thick glass.) One caution, with any head covering: Make sure it's well enough ventilated to be safe to wear!