Cast Acrilic has better scratch and chemical resistance, and far better UV resistance, Polycarbonate wins for absolute strength, but acrylic is a far better material for most boats. Polycarbonate gets its impact resistance from slight flexibility; large, unsupported polycarbonate hatches can sag where acrylic hatches will not. Unless the boat operates in an environment
where impacts are likely, you will get far better performance from an acrylic hatch
. As an added benefit, acrylic is much less expensive than polycarbonate.
use cast acrilic the only hatch manufatture that I know that uses polycarbinate is Bomar
Why use CAST Acrylic verses EXTRUDED Acrylic ?
Temp: 180 F (Cast) vs. 160 F (Extruded)
Cast acrylic has a higher molecular weight, therefore it will cut, drill and rout cleaner. As you machine cast acrylic, the shavings will flake off whereas the extruded acrylic shavings can gum up on the tool.