Polystyrene is a lightweight extruded foam with many uses, from thick sheets used as signage and theatrical sets, to thin sheets used in the creation of architectural models. Though solid in appearance, traditional cutting methods using saws will leave jagged edges and small foam debris, as the cutting process tends to break through the foam rather than glide through in an even cut. The cleanup process using traditional methods can take as long as the cutting itself. A hot wire cutter provides a faster method without the mess. The hot wire cutter created for foam use slices through the polystyrene sheets smoothly, melting through without jagged edges or crumbling foam.
Mark the cutting line across the sheet using a pencil.
Turn on the hot wire foam cutter. Wait for the wire to heat to a dull red colour, indicating that the wire is hot enough to cut through the foam.
Align the hot wire with the marked line on the sheet. Press the wire against the sheet, allowing the heat to cut smoothly through the polystyrene along the line.
Turn off the wire cutter and wait five minutes for the foam to cool completely. Clean up the cut line to remove any loose foam by rubbing the cut edge against the flat surface of a second polystyrene board.
Cutting through polystyrene sheets using hot wires creates an unpleasant odour. Make the cuts either outdoors or in a well-ventilated area.