Yeah, extruded polystyrene. Stuff seems easy to work with. I've been using a steak knife for most of my cuts!
2" screws, thrown in by hand with a bit, since it doesn't take much.
I was planning on plywood on the hatch body and the hatch itself to insure strength, as well as a good seal.
I started on the sides today... I now realize that will be the greatest challenge and will require a lot of careful shaping! What have I gotten myself into?!
