How to Make Foam Pits

Glue foam boards together using white craft glue thinned with water until it can be brushed on the surface of the foam with a paintbrush. Brush the glue onto the entire surface of the foam being joined and press the boards together until you have a single foam block deep enough to hold your pit plus a quarter-inch in excess.

Mount the newly-created foam block to your baseboard. Baseboards can be of any material that̵7;s flat and stable, such as plywood or medium-density fibreboard. Mount the foam using unthinned glue, spreading the glue onto the bottom of the block and then pressing the block firmly to the mounting board. Take care not to apply so much pressure that you compress the foam. Allow the glue binding the boards to set completely, waiting overnight before creating your pit.

Mark the contours of your pit onto the foam block using a piece of chalk.

Mount a wire attachment onto your hot-wire foam cutter of a size that̵7;s smaller than the smallest diameter area of your foam pit.

Turn on the hot-wire foam cutter. The foam cutter operates by heating a wire to a temperature that̵7;s sufficient for cutting through the foam smoothly and cleanly. Wait three minutes for the wire to reach its cutting temperature.

Use the hot-wire cutter to cut into the foam at the center of your drawn pit. Move the wire steadily, carving a line through the foam. Remove the hot-wire cutter and pull away the cut foam piece. Continue to dig the pit, working from the center out towards the pit contours and downward towards the pit bottom, cutting away the foam in chunks. Remove the foam until you̵7;ve reached the depth and general shape of the pit. Turn off the hot-wire cutter.

Sand the sides and lip of the pit using the fine grain sandpaper to remove the lines left from the wire cutter.