5-Minute Foam Factory

By Bob Knetzger
Category: Tools, Home, Workshop
Time Required: 1 hour
Difficulty: Easy

What keeps your coffee warm but also rides the cold Pacific surf? What’s in the Rock and Roll Hall of Fame but makes an annoying, squeaky sound? Even though it’s banned in over 100 cities, you can find it just about everywhere. What is it? It’s expanded polystyrene (EPS) foam.

Styrofoam is a great insulator (for hot drink cups and wall insulation), lightweight and stiff, and impervious to water (great for surfboards). Unfortunately, it’s also impractical to recycle and can be an unsightly part of the waste stream. Our landfills and waterways are filling up with discarded coffee cups, store meat trays, and take-out packaging.

With this easy hot-wire foam cutter, you can reuse this leftover EPS foam to create treasures from trash!

Once you’ve mastered the basic foam cutting techniques, you can create a double-cut, 3D teddy bear shape, spin a compound-curve cone, and cut a stack of foam sheets to make a blizzard of snowflakes.

Steps

Step #1: Gather your materials.

Scrounge your workshop for scrap materials to build the cutter. None of the dimensions are critical, so feel free to adapt the sizes shown here to use what you’ve got.
When heated, EPS can produce benzene, and when burned, it gives off other noxious fumes. So always use your hot- wire cutter in a very well-ventilated area!
Use the train transformer’s speed control to set the wire temperature: just warm enough to cut the foam. Never cut with a red-hot, smoking wire!
Foam made by Woodland Scenics is specially manufactured so that it doesn’t give off harmful fumes when cut with a hot wire. Get it where model train supplies are sold or at woodlandscenics.com.

Conclusion

For more super cool techniques for cutting hyperbolic, toroidal, and conic shapes, as well as how to use templates, go to http://makezine.com/16/styrocutter.

This project first appeared in MAKE Volume 16, page 114.