How to Mold Styrofoam
Many people think that Styrofoam is difficult to work with, but you can actually mold or cut it to any shape very easily. This material comes in many different densities, so part of the trick is to purchase Styrofoam that has a very high density so it will hold up against your knife or hot wire cutting or sandpapering. If you purchase very thick Styrofoam, you should have no problem shaping it and molding it to your desired shape.
Things You'll Need
- Styrofoam (high density/thick)
- Knife (any kind, as long as it is sharp)
- Hot wire cutter (optional)
Draw the basic idea of what you want to cut out with a pencil. If you're building a model with many pieces, it is important to draw a picture of it fully assembled from several angles as well as pictures of the individual pieces you wish to cut on the Styrofoam. Be sure to include dimensions on your draft.
Cut out the pattern or shapes you want to make with a very sharp knife (any will do, as long as it is sharp). You can also use a hot wire cutter (available at most hardware stores) for this task; that is, a wire held over an open flame. Make sure to leave a little bit of space around the shapes, maybe 5/8 of an inch, to allow you room for sanding and room for error.
Get out your sandpaper. Use a rougher sandpaper to shape larger areas and finer sandpaper to shape smaller areas.
Sand until your Styrofoam achieves its desired look. Paint if desired.
- Knives used to cut Styrofoam must be very sharp and hot wire cutters must be very hot. Exercise caution and keep children out of the way when working with these items.