Here are a couple pictures of styrofoam sculpting. The "Life in Hell" Binky
is a sculpt in Styrofoam I did around 1987(?) with a high density Styrofoam Brand insulation foam.
The picture of foam with the cuts I did yesterday using a sharp knife and X-Acto blade. The foam will dull a blade pretty fast so you need to resharpen
the edge frequently with a sharpener. A small inexpensive V shaped sharpener works great. You can find them in outdoor and sporting good stores for less than ten bucks.
This particular foam comes in 4x8 foot sheets in a variety of thicknesses. If
I remember correctly you can get it up to a foot thick. Most cities have a building or insulation supply house that will carry it. Home Depot and Lowes sometimes carry a similar product that is pink in color and used for insulating
homes. You want the very dense material. The white cellular or puffed and compressed foam is too crumbly.
The dense stuff that I used is carveable and sandable. I word of warning. If you are doing a lot of sanding, wear a mask. Small foam particles get airborned and can be inhaled. Since they are not biodegradable, they will stay in you lungs pretty much forever.
I only carved and painted my stuff, so I don't know if a fiberglass type coating would work or melt it. Someone here probably can answer that.
I used to work for a company that used it for set pieces. We would melt Van Aken clay in a double boiler and brush it on to the foam. Then sculpt or texture additional details.
If you are making a large scale sculpture that you intend to mold and cast in
something else, this technique will let you build big items that don't weigh a ton.

