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1945 Theatre Catalog, 4th Edition, Page 168 (146)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 168
Page 168

1945 Theatre Catalog, 4th Edition, Page 168

When all magnesium was allocated to the war effort, the manufacturers of warp beams had to substitute fabricated steel beams which were twice as heavy. They report that even though the magnesium beam: at present are more expensive, their customers are anxious to replace the wartime steel beams with magnesium. Their lightness, rigidity, strength and durability make them highly superior.


General Considerations

Although most of the equipment mentioned is not of direct interest to theatre designers and owners, it has been described simply to illustrate the properties of the metal and the variety of ways in which it can serve. In addition to properties, available forms, and serviceability, the theatre industry will be vitally interested in the surface quality and types of finishes applicable to magnesium.

For exterior exposures, magnesium is highly resistant to corrosion in ordinary atmosphere, and in salt water atmosphere is better than iron or ordinary steel, though not as resistant as stainless steel. For the latter type of service, suitable paint systems provide adequate protection. The metal is first given a chemical treatment, such as chromepickle, and zinc chromate primers are recommended before application of suitable weather resistant paint.

For interior use almost all types of decorative paints may be used, such as the baked enamel finishes, crackle paints, and pigmented lacquers. Decorative chemical finishes have also been developed. One of the best is an anodic coating which provides good protection and abrasion resistance as well as pleasing appearance. This coating may also be dyed to many different colors.

The cost of magnesium to the pound is slightly higher than for the other common metals. When making a cost analysis of magnesium, however, users should

DIE CASTINGS OF DDWMETAL indicate the great variety of forms (left) to which the Dow Chemical Company's metal can be put. At the right are film magazines for sub-standard motion picture cameras, where the properties of magnesium


keep in mind that, although metals are purchased, on a pound basis, they are most often used on a volume basis. Because of magnesiumis lightness, fewer pounds are required than with other metals, savings may be realized on machining, shipping, and handling costs, and the resultant weight reduction may be worth cost savings to the consumer. These factors should be taken into consideration in analyzing the economies of using magnesium. In some products a manufacturer may actually realize cost savings through using magnesium. The cost of other products may be higher, but the use of the lighter product may result in savings to the ultimate consumer.

Specific Suggestions

There are dozens of ways in which theatre designers and theatre equipment suppliers can probably utilize magnesium to advantage. These might be classified into four different groupsearchitectural or structural members, projection equipment, maintenance equipment, and miscellaneous equipment.

Architectural applications for magnesium include spandrels, marquees, gates, doors, lighting fixtures and hardware. Marquees should particularly benefit by using magnesium structural members. Here is a part of a theatre in which weight has no useful function, and each additional pound necessitates additional structural supports. Consideration has already been given to lightweight spandrels in large buildings. A variety of decorative finishes could be uced to obtain artistic effects. Portable stage platforms and orchestra platforms which must be raised and lowered could be made both lighter and more durable by using magnesium.

Some manufacturers of projection equipment are already using magnesium to advantage. Projector parts (usually die cast), film magazines, and other items have been made. In such equipment not only lightness is an advantage, but the thermal conductivity of the metal is important.


Maintenance of any building constantly used by the public is a considerable cost item. Care of the beautiful rugs and carpets in theatres, for example, is a constant problem. Cast magnesium

, parts are already being used in vacuum

cleaners. The lightness of these units saves wear on rugs in cleaning, and enables the maintenance worker to do more work with the same amount of effort. Magnesium ladders are now being made which are safer and more durable than wooden ladders, and considerably lighter than those of steel construction. Lightweight scenery handling equipment, hand trucks, and other items could be truly labor-saving devices.

Air conditioning is used in every good theatre. Large magnesium fans have been used for a number of years, in which this lightweight metal reduces the effect of centrifugal forces and lowers power requirements because of reduced inertia. Theatre owners might well consider the use of magnesium in cooling fans as a means of cutting operating costs. Letters and numerals, signs, and display racks and cases which must be constantly changed and handled manually, auditorium seats and miscellaneous furniture are other types of equipment in which magnesium could be used to advantage. Magnesium furniture has already proven highly serviceable. For example, one hundred magnesium ballroom chairs have been in service in a certain country club for over ten years. They are lighter than comparable chairs of wood construction, have never had to be repaired, yet are still in excellent condition with respect to both rigidity and finish.

* * at

New structural metals do not come into being every day or every year. Here is an opportunity for all concerned with theatres to take advantage of a metal which went into a war comparatively unknown and has come out a youthful but full-fiedged member of our group of structural materials. The door has been opened on a whole new field for the designerls imagination.

stand in good stead. In the text are noted other uses for the metal in theatres, where strength and durability can be combined with lasting beauty. Some possible uses of magnesium in the theatre of the future are outlined in the text.

1945 Theatre Catalog, 4th Edition, Page 168