Editing Set Construction at MCHS

This article describes set construction basics at MCHS.  The scene shop was originally equipped with a dozen or so cordless drills/screwdrivers.  At the time, it seemed like an extravagance, since one could buy a dozen hammers for the cost of just one cordless drill.  The benefits became soon became obvious:
* Set construction is less tiring, and since less upper body strength is needed (vs. hammer and nails), more people can participate
* Strike is much faster and easier, and there is less damage to the wood, enhancing reuse
* Screws are stronger than nails, so less of them are needed for equivalent strength.

Although there is certainly is a wide variety of structural materials used in MCHS sets, the majority fall into a handful of categories.

==Structural wood==
Three sizes of "stick' lumber are in common use

===2 x 4===
A "2x4" is really 1 1/2" x 3 1/2" and is made of either spruce, pine, or fir, with pine being the most common.  MCHS typically buys them in twelve foot lengths, although frequently eight foot (96") or 93" sizes are on sale and we'll do a buy of those.  Typical uses of 2x4's are for platform legs, heavy duty framing, bracing, and other application requiring a strong and fairly stiff structural member.

===2 x 6===
A "2x6" is really 1 1/2" x 5 1/2" and is made of either spruce, pine, or fir, with pine being the most common.  2x6's are almost exclusively used in MCHS for outside edge of stage platforms.  A properly build 4' x 8' platform built with 2x6's only requires legs at the corners, while a corresponding platform build with 2x4's should have additional legs at the midpoints. 

===1 x 3===
A "1x3" is 3/4" x 2 1/2" and is almost always pine.  Occasionally, we'll get a good buy on "1x4" so be sure and measure first if the exact width of the board make a difference in what is being built.  1x3's are used for the framing members in flats and other light duty applications.  

==Sheet goods==
Two types of sheet lumber are in common use for MCHS construction.  They are both supplied in 4' x 8' sheets.

===Luan===
Luan is a thin (1/4") wood used for facing, mostly for flats or as skirting around legged platforms. Luan's advantages are that it is smooth and relatively cheap.  It takes paint well without surface prep.  On the minus side, it splinters very easily, warps if wet, and does not take point loads well.  A properly built luan flat is very durable and can be used again and again.

===Decking===
Decking refers primarily to 3/4" inch plywood used to provide the walking surface for platforms.  3/4" ply is very strong and makes a very rigid and sturdy platform.  

==Other materials==
Smaller sizes of stick lumber are sometimes used for decorative items like fence pickets, props, etc. Occasionally, platforms will be covered with Masonite or MDF if an extra smooth surface is needed. Foam used to insulate homes makes a lightweight material for facades.  EMT (thinwall steel tubing) is used to support lightweight materials such as signs or banners, while heavier 2" steel pipe is used for structural support.  Fabrics such as muslin are used for backdrops, while thin sheets of Lexan have been used for on stage windows.  

==Properties of materials used in MCHS stagecraft==
The choice of materials for each part of a set is the result of careful consideration of its characteristics, its advantages and drawbacks.  For example, materials used in stagecraft must be relatively cheap, easy to cut and drill with conventional tools, and light enough for students to handle.  They must not be extremely flammable or hazardous for untrained people to handle.

==Wood==
Wood is great material for stagecraft because it is light, strong, and can be easily cut and drilled with a wide variety of hand and power tools.  Wood is substantially stronger along the "grain" than across.  Wood, particularly pine, is easy to split along grain lines.  Avoiding splits often requires that screw holes be predrilled.  Select a drill that is roughly the same size as the shank of the screw. You should be able to hold the drill in front of the screw and see all of the threads showing behind the drill. 

Plywood is made of many thin sheets of wood glued together with the grain in opposite directions.  This makes plywood equally strong in both directions and less resistant to splitting.  However, plywood does not hold screws as well as an equivalent thickness of solid wood.

Both Masonite and MDF are manufactured from wood fibers and do not have wood grain like plywood or luan.  They also have a high content of a binder (glue) which dulls saw blades quickly. These manufactured materials are not very rigid or strong and require appropriate bracing.

==Steel==
Occasionally, MCHS crew will encounter steel in the form of thin plates used for bracing or pipes. Steel is strong, although it can be heavy in the larger sizes.  Steel is tough to drill, requiring sharp drills designed for drilling metal and often lubricating oil to keep the drill bit cool.  Cutting steel tubing or pipe often requires special tools and always requires patience.

==Plastic Sheets==
Plastic sheeting has been used to create the illusion of a glass window, or create places to shine lights through otherwise solid structural members.  Both Lexan (polycarbonate) and acryclic plastic have been used.  Acrylic is somewhat more likely to shatter when cut in a power saw, but both materials must be cut or drilled slowly and with caution.