Plastic and Foam

Plastic comes in an infinite array of formulations and shapes. The kinds that we use most in theatre are often plastics that are used in the construction industry and are very cheap. On the whole, plastics can be cut easily, reshaped with a little heat, and are light weight.

Foam• Polystyrene, expanded,

extruded

• cutting, shaping , hot wire

• painting, coating

• adhering, liquid nails

Polystyrene foam (Styrofoam) comes in

two basic types: Expanded- this is made as small beads of polystyrene that are

expanded using steam. This type is usually white and comes as sheets from the lumber yard or as packing material.

Extruded- this is formed as a smooth foam without beads. It is usually blue or pink. This stuff is used to carve detailed shapes that the beaded foam can’t do.

Cutting foam is easy. Any saw can do it. It can be

routed or carved using almost any tool. To make some of the more detailed shapes, or to mass produce pieces, polystyrene can be cut with a hot wire. This method is used by shops that have the facilities to deal with the fumes. Burning or cutting with a hot wire releases some very toxic gases and should only be done while wearing a respirator.

Most glues don’t work on foam. They either

don’t stick to the foam or they dissolve the foam chemically. The glue we almost always use is called Liquid Nails. Make sure you use the kind formulated for sticking to foam.

Painting foam is also a problem. The uncovered foam does not take paint correctly and looks funny. For most uses we need to first coat the foam with any number of specialty products or home made mixes (Joint compound, water, and glue + saw dust or sand or cat food….)

Uses of foamWith all these difficulties why do we use foam? It is cheap, it is very light weight and

it can be shaped into anything we want. There are many sets that can’t be made without foam.

Additional Foam materials

Ethafoam- This is what pool noodles are made of. We use the noodles or insulation tubes or backer rod for a variety of props and detail.

Great Stuff- This comes in a can and is sprayed out. When it hits the air it expands and hardens. After a day it can

be carved and shaped into whatever we want.

foam rubber- Upholstery foam. You and your bottom are very familiar with this kind of foam.

It has its uses, but for large scale applications its expensive. To paint we have to use spray paint to

allow for the foam to move and compress.

latex and prosthetic foam- Special effects makeup.

Most Used types of Plastic• Plexi glass

• vinyl, filon, corrogated roof

• PVC, pipe

• recycled bottle lumber

• tubing

• fibre glass

• vacuformed plastic, thermo plastic

Plexiglas is a brand name. A better term would be sheet

acrylic. This material is clear like glass but flexible to a point. It does break but not like glass. As a plastic it is lighter than glass but its much better in its ability to be worked. We can cut it with the same saws we use for wood and when heated it can be bend and will retain its new shape when it cools.

It comes in 1/8 inch and 1/4 inch standard thicknesses but thicker material can be ordered. The price is by volume so thicker stuff is proportionally more expensive

Vinyl is a common material. Most often seen as corrugated roofing

material. (one brand name is Filon) This stuff comes in many colors and styles and can be painted opaque or left translucent. What we use it for is up to our imagination.

Everyone thinks of Fibre Glass as the pink panther foam in

the attic. But in another form fibre glass becomes an almost perfect building material. The fibre glass comes in woven sheets and is applied with a two part resin in overlapping coats. This is how boats are made, and how a lot of scenery for outdoor use is made. Most specialty pieces at the theme parks and along 192 are made of fibre glass. This material is weather proof and paintable, light weight and very strong. But there is a fume issue when working with the resin.

PVC stands for poly vinyl chloride. This plastic can be formed

into a wide variety of forms, including clothing. The way we usually find it is as plastic pipe.

We can use this as pipe, or cut into half rounds or quarter rounds. It also can be heated and shaped.

We in America drink a lot of soda. We also recycle most of the bottles. This plastic is not very useful to make more bottles but it is turned into

lumber. This recycled plastic lumber is weather proof and is very useful in building outdoor structures in Florida.

Tubing- lots of sizes and colors and materials. What can we do with it? Just use your imagination and it can become - a wrought iron gate, the antenna on bugs, the set dressing in a alien sci fi movie, etc…..

One kind of plastic that has a specialized use in theatre is

Vacu Form Plastic or Thermo Plastic. This material comes as sheets that become moldable at a very low temperature. The sheets are heated to become soft then they are laid over the objects that we are trying to copy and the air is sucked out. After a minute the sheet cools and its ready to be cut or painted. The picture to the right is a

link that takes you to a manufacturer of large sheets of architectural detail. If you want to cover your set with brick or stone or fancy doors and panels this is your source. This stuff is a trade of money for time- you can make the set quickly but it will cost. Link to manufacturer

In your life you will see many new kinds of plastic and foam come into theatrical use. You may be the one to introduce some material from the civilian world into the entertainment

industry.