How to Bend and Shape Styrofoam

Styrofoam, which is also known as polystyrene, is a hard foam material often used in building props and models. The foam is used as a "core," or inside piece, for a fiberglass or other plastic coating. In order to use Styrofoam as an effective core piece, you must first form a block or sheet of the material into the shape you need for your project. This may require cutting and/or bending before the Styrofoam is properly shaped for your purposes.

Things You'll Need

  • Paper pattern

  • Styrofoam blocks or sheets

  • Craft knife

  • Wax

  • Wire brush

  • Ice scraper

  • Cheese grater

  • Wooden dowels

  • Clamps

  • Plastic tub

  • Hot water

Step 1

Lay the paper pattern for the object you want to make over a Styrofoam sheet or block. This should be a simple drawing of the overall shape you need the Styrofoam to have. You can tape the paper pattern in place, if necessary.

Step 2

Apply a small amount of wax to a craft knife so that the knife will cut smoothly. Cut the Styrofoam along your paper pattern lines until you have a rough overall shape.

Step 3

Remove the paper pattern from your Styrofoam piece. Refine the shape by carving around your cut edges again. If you would like a smoother line, you can use an electric, hot-wire Styrofoam cutter.

Step 4

Add the texture you would like your Styrofoam piece to have. If you are making a prop, you may be looking for a rough or rock-like texture. Flake pieces of Styrofoam off the overall piece using tools like a wire brush, an ice scraper and a cheese grater.

Step 5

Bend your Styrofoam piece if you require a curved shape for your project. Take a few wooden dowels or pieces of wood in the size curve you need, and fit the Styrofoam piece around them. Clamp the dowels together, sandwiching the Styrofoam between them.

Step 6

Fill a plastic tub with water that is heated to 90 degrees Celsius. Immerse the clamped Styrofoam in the water. Do not touch the hot water with your hands.

Step 7

Remove the Styrofoam from the water once it has cooled enough to touch. Remove the wooden dowels. Your Styrofoam piece will have formed to the shape of the dowels.

References & Resources