MATERIAL Styrofoam sheets- a 4'x8'x2" sheet of foam is about $22 at Lowes or Home Depot. It comes 1/2", 1", 1 1/2", & 2" you can get some thicknesses in half sheets. Walmart & Michaels sell some smaller sheets but it is very low quality, brittle, and more expensive. Lowes and Home Depot also sell a pink or blue high density foam which is more expensive and slower to cut, but more durable.ADVANTAGES Cheap, lightweight, easy to work with.
GLUE White glue works but does not dry well on large projects. Gorilla Glue or Ultimate Glue (seem to be the same thing but Ultimate is cheaper) work well but need some moisture - dampen both pieces of foam with water first. Pin in place with toothpicks or bamboo skewers, leave the picks in for added strength. Allow to dry for at least 2 hours (patience!)
SCULPTING I bought a $10 soldering iron from Harbor Freight and replaced the soldering point with a loop of heavy wire. It can carve out a channel about 3 inches wide and 2
inched deep, it was used on the cactus and tiki below. I also use a wood-burning tool for more delicate operations like the tombstone lettering below
The idea is to make 3 cuts along the edge of the foam to round it off (Fig. 1). If you want, draw lines on the 2 edges of the foam to guide you (Fig.2) then cut with the Wonder Cutter (Fig. 3). Fig 4 shows after the first cut. Mark and cut the second cut (Fig.5), and the third cut (Fig. 6)
*Use latex house paint or acrylic craft paint, not spray paint or oil based paint as they will eat the foam. After a few good coats of latex you can use spray paint for shading, etc. If you really need to use spray paint for a special effect like metallic, use a base coat of something other than white so you can see if you have covered the styrofoam. Any pin-holes in the latex will allow the spray paint to dissolve the foam.
*Krylon H2O Spray Latex paint works great, especially on small items like letters. Krylon H2O has become hard to find, they may have discontinued it?
*Use spray adhesive to glue mylar film to the foam BEFORE you cut it. The heated wire will cut through the mylar film and the foam together, resulting in a perfect trim job.
*After painting, coat with white glue and glitter
*Use fabric or fake fur and white glue to cover the foam
*Use wrapping paper, texture scrapbooking paper, aluminum foil, etc.
*Paint and coat with glass beads for a refective surface. (You can probably get a cupful of the glass beads from your local Highways or Public Works Department)
*There is at least one commercial coating, "Steve's Coating for Foam", which can be used over styrofoam to make it more permanent. But it is rather expensive and I wasn't all that impressed with the results. I used Steve's Coating on the Moai at the bottom of the page, it took $45 to coat it and I'm not sure it protected any better than a couiple of good coats of latex paint.
You can coat foam with Monster Mud (1 part latex paint and 4-5 parts premixed wallboard joint compound). If it will be displayed outdoors, the Monster Mud needs to be painted with clear polyurethane or exterior latex paint
FOAM REPAIRS Sometimes your foam creations may need some repairs from accidents that happen during or after making them. If a piece breaks off, save it and glue it back on using Gorilla Glue and skewers. If a chunk is missing, it can often be repaired with GreatStuff expanding spray foam. In the pictures below, I had made a mistake and rounded off the wrong side of the cougar's face (Fig. 1). First, spray some GreatStuff in the gap (Fig. 2), allow it to expand and cure overnight (Fig. 3). Use a sharp serrated knife to trim off the excess. The GreatStuff often creates bubbles as it cures and the surface wont be as smooth as the original styrofoam. If it is in a critical area,
smooth it out with paintable caulking and paint it when the caulking is dry.
HANGING YOUR CREATION
If you are hanging a sign, you'll need 1 or 2 anchor points. Pick up some large plastic screws used for drywall and some eye-screws about the same size as the metal screws that come with the plastic screws. Screw the eye-screws into the plastic screws and screw the plastic screw into the styrofoam. Screw the plastic screw out and dip it in water, put a drop of Gorilla Glue in the hole and screw the plastic screw back into the into the hole.
A 13 ft tall giraffe made for Serengeti Trek VBS.
A year later, I re-worked the giraffe. It was originally made to go up on a stage where it would only be viewed in profile and it was only 10 inches thick, a rather skinny giraffe. I needed to use it again in an area where people whould be walking all around it so I bulked it up. I increased the neck, shoulders, and "hips" from 2 inches thick to 6 inches thick each then used a serrated knife to round them out. This brings it to 22 inches wide.
Signs for Serengeti Trek, Jerusalem Marketplace and Fiesta! VBS, the letters on the Serengeti Trek sign are covered in animal print fabric..
A pair of Gerenuk and an Ostrich with his head buried in the sand for Serengeti Trek VBS. The ostrich was painted grey then real ostrich feathers were added to the tail & wings
A Llama head made for the "Temple of Chili" booth. The styrofoam pieces were glued together and the edges rounded off with a Wonder Cutter, some detailing was done with a hot solder iron. The foam was painted then covered with faux fur, black pipe-cleaner eyelashes were added after this photo was taken.
A 7x3 foot waterfall panel for the "Temple of Chili" booth.
Decorations used at my daughter's wedding reception - an 8 ft champagne bottle, 4x8 ft interlocking rings & hearts. The rings and hearts were painted with latex paint, sprayed silver, and covered with glitter.
A tombstone used in an anti-smoking campaign, an example of spray paint over latex.
A 5 ft tall Dragon head for "Sir George's Dragon Chili". Sides of head and horns are made of styrofoam, these face sides were attached to a tapered wooden box that housed a fog machine. The neck is Monster Mud over burlap and chickenwire. The head and neck were mounted on a wooden framework to make a 13 foot tall dragon looking over an 8 foot wall.
An 8 foot cactus for Fiesta! VBS made from two 1x4 foot columns of styrofoam. The top was rounded with a serrated knife and a Surform rasp. The ridges were cut with a hot soldering iron. Goat with motorized head made for same VBS
A floating tiki pool decoration for a luau. Made from a column of 12 inch diameter foam carved with a soldering iron.
A roaster oven transformed into a roasted pig for the luau. Styrofoam carved with a handsaw and serrated knife, coated with tan Monster Mud, and "honey glazed" with oak PolyShades (polyurethane & stain combination)
How do you carve a foam hippo head? Take a block of foam and cut away everything that doesn't look like a hippo. 10x20x40 inches, carved with a handsaw and a serrated knife, spray painted with Krylon H2O latex.
A 2x3 foot book made with foam & foam-core posterboards, then covered with brown vinyl.
A faux stone fireplace to surround a plasma TV. The pillars and mantle were coated with monster mud and spray painted with Fleckstone paint
A Lion Dance mask. Simply a modified cardboard box with some styrofoam attached. Not a very traditional design, but it worked for me :)
A foam eagle with a 42 inch wingspan for Avalanch Ranch VBS
An 8 foot cougar made for Avalanche Ranch VBS
4x5 foot sign made for a class reunion using the same pattern as the cougar above. The letters are covered with red Mylar film.
Classroom decorations for a local biology teacher. The cell and beetle are 2x2 feet, the frog is 2x3
A 3 foot tall sunken Easter Island Moai carved from a block of foam using a saw and a SurForm shaper. It was coated with "Steve's Coating for Foam", a couple of coats of latex paint, a coat of spray Fleckstone, and a wash of blue and green acrylic craft paint.