Set Construction at MCHS
From Mchs Theater
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==Structural wood== | ==Structural wood== | ||
| - | + | Four sizes of "stick" lumber are in common use | |
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| + | ===2 x 2=== | ||
| + | A "2x2" is really 1 1/2" x 1 1/2" and is made of either spruce, pine, or fir, with pine being the most common. MCHS doesn't typically buy 2x2's, but creates them from ripping 2x4s lengthwise. Note that simply ripping a 2x4 yields a stick that is approximately 1 1/2" x 1 5/8". We typically make the extra cut to square them up to avoid errors caused by careless assembly of not quite square lumber. 2x2s are used for smaller projects where the strength of a 2x4 is not needed and the weight would be a disadvantage. | ||
===2 x 4=== | ===2 x 4=== | ||
Revision as of 19:43, 26 June 2009
This article describes set construction basics at MCHS. The scene shop has a few wood working power tools (table saw, band saw, and chop saw), but no metal working capability to speak of. Wood and its variants are the major structural elements of MCHS sets. The scene shop was originally equipped with a dozen or so commercial quality 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.
Contents |
Structural wood
Four sizes of "stick" lumber are in common use
2 x 2
A "2x2" is really 1 1/2" x 1 1/2" and is made of either spruce, pine, or fir, with pine being the most common. MCHS doesn't typically buy 2x2's, but creates them from ripping 2x4s lengthwise. Note that simply ripping a 2x4 yields a stick that is approximately 1 1/2" x 1 5/8". We typically make the extra cut to square them up to avoid errors caused by careless assembly of not quite square lumber. 2x2s are used for smaller projects where the strength of a 2x4 is not needed and the weight would be a disadvantage.
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 there will be 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 built 4' x 8' platform with 2x6's only requires legs at the corners, while a corresponding platform built with 2x4's should have additional legs at the midpoints. This makes for a more rigid and versatile platform.
1 x 3
A "1x3" is 3/4" x 2 1/2" and is almost always pine, although spruce is used as well. Occasionally, MCHS get a good buy on the "1x4" size 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, bracing, 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 finished smooth, has tight grain, and is 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 faced 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 rigid and sturdy platform. A 4' x 8' sheet of decking is heavy and awkward and must be handled carefully to avoid injury.
Other materials
Smaller sizes of stick lumber are sometimes used for decorative items like fence pickets, props, etc. Occasionally, platforms will be covered with an additional layer of 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 at this level must be relatively cheap, easy to shape with conventional tools, and light enough for students to handle safely. They must not be require special handling, storage, or assembly procedures.
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.
Foam Insulation
Foam insulation typically comes in 4' x 8' sheets of 1/2" thickness. Insulation can easily be cut with a utility knife and if supported properly, on any of the power saws. As a structural material, foam insulation is weak and almost always must be braced or supported in some way. It is very useful in adding dimensionality without weight and can be directly hot glued (on low) to vertical surfaces. If screws or nails or used to hold insulation on a curved surface, washers may be needed to keep the fasteners from pulling through the foam. If the plastic sheet is peeled off, insulation takes paint fairly well.
