I'm looking to build a form from which to make GRP shapes. I think the way
I'll go is to build a male from sheets of foam, between which will be glued
sheets of thin ply cut to the contour at that point. I'll hot-wire cut the
foam from edge to edge of the ply sheets, fill/smooth/paint the form, make
a female, then make the final items.

So if there was a simple freeware cad program that would let me make a 3-d
image and then "cut" it at 2" slices, giving me the plan view of each
slice, that'd be perfect. Is there?