Foam Carving
Rigid foam insulation board is the most versatile material in home haunting. It's cheap, lightweight, easy to carve, and can be shaped into tombstones, architectural details, rock walls, creature parts, and scenic elements. This guide covers the tools and techniques for working with it.
Foam Types
- Extruded polystyrene (XPS) — The pink or blue board from hardware stores (Owens Corning or Dow). Dense, smooth, carves cleanly. This is what you want for most haunt work.
- Expanded polystyrene (EPS) — The white beaded stuff (like packing material). Cheap but crumbly and messy. Avoid for detailed work. Okay for rough filler.
- Polyisocyanurate (polyiso) — Yellow foam with foil facing. Works for flat panels but doesn't carve as well as XPS.
Cutting Tools
- Utility knife — For straight cuts through thin board. Use a long blade and make multiple passes rather than trying to cut through in one stroke.
- Hot wire cutter — A heated wire that melts through foam cleanly. Makes smooth, precise cuts. Commercial versions are available, or DIY from nichrome wire and a power supply. Work outdoors — cutting foam produces fumes.
- Soldering iron / wood burner — For detail carving: lettering on tombstones, texture, crack lines. Different tips create different textures.
- Rasp / surform tool — For shaping edges and rounding corners.
- Dremel rotary tool — For fine detail work with carving bits.
Sealing Foam
Raw foam is fragile and absorbs paint unevenly. Seal it before painting:
- Latex paint — Several coats of cheap latex paint fills the surface and provides a paintable base. The simplest sealer.
- Drylok — Masonry waterproofer. Creates a hard, durable shell over foam. Excellent for outdoor props.
- Mod Podge / white glue wash — A coat of diluted white glue hardens the surface.
Warning: Never use solvent-based spray paint or contact cement directly on polystyrene foam — it melts. Always seal with latex paint or Drylok first. After the seal coat dries, spray paint over it is fine.
After sealing, proceed to painting and weathering for the finish coat.