Working With Foam

by Andy Slater

Have you ever flicked through the projects and plans section of the Hobby's catalogue and wished that you had the necessary woodworking skills to make all those wonderful toys and other items? Well here's an alternative: use foam instead.

The kind of foam that we're talking about here is rather like the white beaded stuff that's often used as packing materials for electrical and other household items. You can use that type but good craft suppliers such as Hobby's also stock denser types such as polystyrol and craftfoam. These denser foams are more robust than the white stuff and do not have the give-away bobbly texture.

Of course even the densest foam is softer than wood so if your child is likely to want to stand on or attempt to eat the toy garage, farm, airport, moonbase or whatever you were thinking of making, then you might be as well to postpone the project for a year or two. If however they've reached the stage where an average plastic toy will survive beyond Boxing Day then you can probably use foam to make any accessory or play environment their heart desires. And it's not just kids stuff either, clocks, trinket boxes, picture frames, you name it. I've even made a storage unit that's fixed to the wall above my work table.

Incidentally, those aren't my hands in the picture with the clock but it didn't take long seeing me use these tools before my wife wanted in on the act.

So how do you work with foam?

Well, you can cut foam with craft knives and even a saw will work on the denser stuff. However it blunts blades rather quickly and a dull blade will tend to drag rather than cut. It can also get quite messy. By far the best thing to use is a hot wire foam cutter.

As the name suggests, a hot wire foam cutter works by heating a wire, 'blade', or tip which then melts through the foam like a hot knife through butter. Straight cuts can be made using a strip of wood or cardboard as a guide while curves can be done freehand. You can also use a template, made from cardboard if you want more than one of the same item. That's how I did the gulls for the mobile shown in the accompanying pictures while the VW clock was done freehand; by simply sketching the design onto a sheet of polystyrol, cutting it out with the Sculpting Tool, and engraving lines with the Engraving Tool.

As you can see from the other images, you can also join pieces of foam together and paint them. To join foam use Foam-2-Foam glue from Deluxe Materials, PVA, epoxy, or hot glue. Hot glue has the advantage, when gluing small areas, of being fast. For large areas however, where the hot glue might begin to cool before you've covered the whole area to be joined, one of the other adhesives will be better. Modelling pins can then be used to hold the foam in position while the glue dries.

Spirit and cellulose-based paints eat into foam but most water-based paints can be used. Be warned that some acrylics contain substances that will eat into the foam so doing a test on a piece of scrap is a good move. The models shown in this article were painted with Miniature Stone Coating or Hobby's Poster Paint.

Note that there are a few precautions that you should take when using the tools. If you keep the wires/blades free from melted residue they won't create much of a smell however it's better to avoid inhaling any fumes that might be created so a well ventilated work area is a must. It's also true that while the tools can't cut you, and won't burn you so badly as something like a soldering iron, you should avoid touching the hot wire against anything other than foam. There's a handy switch on the Hot Wire Foam Factory tool handles so you can turn them off immediately that you're done cutting and you should get into the habit of doing this.

A final thing that I should warn you about is that these tools are seriously good fun. Not only will you find yourself making things that you couldn't make before but you'll also find yourself making things from foam that you would previously have made from plastic, cardboard, or other materials. Indeed you'll probably find yourself cutting wiggly shapes out of spare bits of foam just for the fun of it. I know I do.