Theatres, motion pictures, television, theme and amusement parks and similar entertainment enterprises all build and paint scenery and make props for their presentations. In many cases, these are made in-house. There are also commercial scenic shops that specialize in making large scenery which is then transported to the site. The major difference between making scenery backstage in a small theatre and building huge sets or even houses for a motion picture, for example, is the scale of the work and who does the work. In small theatres, there is little division of tasks, whereas in larger facilities, there would be a division of labour among carpenters, scenic painters, welders, prop makers and so on.
The scenery for a theatre play, motion picture set or television studio might look realistic, but is often an illusion. The walls of a room are usually not solid but are composed of lightweight flats (panels of painted canvas stretched on wooden frames). Background scenery often consists of backdrops (huge curtains painted to represent the background) which can be lowered and raised for different scenes. Other solid-looking props, such as trees, rocks, vases, mouldings, sculptures and so forth, might be made out of papier mâché, plaster, polyurethane foam or other materials. Today, a wide variety of materials are used to make scenery, including wood, metal, plastics, synthetic fabrics, paper and other modern industrial products. For scenery which performers will walk or climb on, the structures must be solid and meet proper safety standards.
The basic processes and chemicals used for making sets and props tend to be similar for the various types of entertainment facilities. Outdoor sets, however, can often use heavy construction materials such as cement on a large scale, which would be impractical inside due to smaller load-bearing capacities. The degree of hazard depends on the types and amounts of chemicals used, and the precautions taken. A theatre might use quarts of polyurethane foam resin for making small props, while the inside of a tunnel in a theme park set might use hundreds of gallons of the resin. Small in-house shops tend to have less awareness of the hazards, and overcrowding often creates additional hazards due to the proximity of incompatible processes such as welding and use of flammable solvents.
Wood, plywood, particle board and Plexiglas are commonly used in constructing sets. Hazards include: accidents with woodworking machinery, power tools and hand tools; electrical shock; fire from combustible wood dust; and toxic effects from inhalation of wood dust, formaldehyde and methyl methacrylate decomposition products from machining plywood, particle board and Plexiglas, and solvents used with contact adhesives.
Precautions include machine guards, proper electrical safety, housekeeping and adequate storage to reduce fire hazards, dust collectors, adequate ventilation and eye protection.
Welding, Cutting and Brazing
Steel and aluminium frameworks are commonly used for the construction of sets. These are often welded using oxyacetylene torches and arc welders of various types. Injury hazards include fire from flying sparks, fire and explosion from compressed gases, and electrical shock from arc welders; health hazards include metal fumes, fluxes, welding gases (ozone, nitrogen oxides, carbon monoxide) and ultraviolet radiation.
Precautions include removal or protection of combustible materials, proper storage and handling of compressed gas cylinders, electrical safety, adequate ventilation and personal protective equipment.
Paints, lacquers, varnishes, dye solutions and other coatings are used for painting scenery flats and fabric drops. The paints and dye solutions can be either solvent based or water based. Powdered pigments and dyes are usually mixed in the shop, with the use of lead chromate pigments still being common. Large flats and drops are often sprayed. Solvents are used for dissolving dyes and resins, thinning, removing paint and other coatings and for cleaning tools, brushes and even hands. Hazards include skin contact with solvents and inhalation of solvent vapours, spray mists and powdered dyes and pigments. Solvents are also fire hazards, particularly when sprayed.
Precautions include elimination of lead pigments, using water-based paints and dyes, adequate ventilation for use of solvents, respiratory protection for spraying, proper storage and handling of flammable liquids and proper disposal of waste solvents and paints.
Polyurethane foam resins, epoxy resins, polyester resins and other resins are commonly used to make large sets and props. Spraying of polyurethane foam resins containing diphenylmethane diisocyanate (MDI) is particularly dangerous, with hazards of chemical pneumonia and asthma. Epoxy resins, polyester resins and solvents have skin, eye and inhalation hazards, and are fire hazards.
Precautions include substitution of safer materials (such as cement or celastic instead of spray polyurethane foams, or water-based materials to replace solvent-based types), local exhaust ventilation, proper storage and handling, proper disposal of waste materials and adequate personal protective equipment.
Props and Models
Plastic resins are also used to make body armour, face masks, breakaway glass and other props and models, as are wood, plaster, metal, plastics and so on. A variety of water-based and solvent-based adhesives are also used. Solvents are used in cleanup. Precautions are similar to those already discussed.