Scenery Building: Caves out of foam

My middle son and I are working on enough cavern scenery to cover a 4X4 table (hopefully by November). And if anyone else is interested in making some for themselves, or working on their own projects and hanging out, I'll be at Mythos most Tuesday evenings between now and then.

I have a variety of types and sizes of foam, cutting tools (both hot wire and mechanical), as well as paints, flocks and other stuff.

Some weeks, my Tuesday visits may devolve into actual role playing (I'll be delivering my youngest son to the teen Savage Worlds group that meets there Tuesdays), but I'll post here when there will for-sure be terrain building going on.