I'm gradually approaching a tricky job. I need to make an accurate set of Perspex "windows" for my FN5 turrets. I know I need to procure and use 0.5mm thick acrylic, and then heat it in a frame before drawing it down over a plug. My intention is to then cut it into smaller panels, painting some to create the curved opaque surfaces and doors at the rear of the turrets. The various panels will then be screwed through brass straps onto the supporting internal structure.
The bit that I'm unsure as to how to proceed, is making the plug. I have a CNC router, so with luck should be able to shape a plug in (say) 50mm layers which can then build up the required shape. I figure some sort of "blue foam" will be a suitable material (I've not used this stuff before). Has anyone hear made canopies using this method, and if so, can you give me any guidance as to particular materials, and how best to smoothly surface a bare polystyrene plug so it doesn't fuse to the hot acrylic being drawn down over it. I figure urethane might do the job if I can stop it attacking the polystyrene.
If anyone has experience in this area, I'd be most grateful for any guidance, as experience had taught me experimentation is expensive!