Time Duration: 1 class period

Unit Title: Sculpture

Lesson Title: Modeling, Carving, Casting, and Assembling

Objectives of Lesson

Upon completion of this lesson, students should be able to:

1. Describe the processes of modeling, carving, casting, and assembling.

2. Identify tools and techniques used in executing these processes.

3. Define kinetic art.

Materials Needed

1. Student Sketchbook, drawing pencil, and eraser.

2. Examples of sculptures.

Instructional Procedure with Approximate Time Line

1. Anticipatory Set (2 minutes)

Artists use a variety of different processes or techniques to create sculptures from the

materials they choose. These processes include modeling, carving, casting, and

assembling.

2. Modeling (10 minutes)

Modeling is a process in which a soft, pliable material is built up and shaped. The artist

uses a material such as clay, wax, or plaster. Because the sculptor gradually adds more

and more material to build a three-dimensional form, modeling is referred to as an additive

process.

With most modeled sculpture the artist finds it necessary to begin by constructing an

armature or support system of some kind. Usually made of metal, the armature provides

the support needed as the artist builds the sculpture around it.

3. Carving (10 minutes)

Carving is cutting or chipping a form from a given mass of material to create a sculpture.

Unlike modeling, which is an additive technique, carving is subtractive. Material is

removed until the sculpture is completely exposed.

Stone carving is a process that has changed little over the centuries. In fact, even the tools

remain essentially the same today as in ancient times. First, a pointed instrument, much

like a large, heavy pencil, is used to cut the general outline of the sculpture to about an inch

from the desired surface. A variety of flat-toothed chisels are then selected to cut away

more stone, gradually revealing the finished form. Finally, flat chisels are used to cut to

the final surface of the work. If a highly polished surface is desired, the sculptor will rub

several abrasive stones over its surface. These stones become finer and finer, smoothing

the surface giving it a warm luster.

Modern stone carvers follow this same process but make use of power tools to cut away

excess material and to polish finished works. This makes the carving process faster, but in

no way minimizes its challenges. Despite its hardness, stone can be broken, leaving the

artist with little more than the shattered pieces of a dream to show for hours of hard work.

Every stone has its own unique character, and the artist must take this into consideration

when deciding upon the right one for his sculpture. Marble is often selected because it

offers a variety of colors and interesting patterns. It can also be polished to a glasslike

surface, or left rough and heavily textured. An example is Michelangelo’s David.

David, Michelangelo

Different textured surfaces can also be realized in another favorite material of sculptors -

wood. For thousands of years woodcarvers have turned to this medium for its warmth,

color, and grain (show examples of Hawaiian sculptures).

4. Casting (10 minutes)

In casting, a melted-down metal or other liquid substance is poured into a mold to harden.

This method allows the artist to duplicate an original sculpture done in wax, clay, plaster,

or some other material. The technique is practiced today much as it has been for hundreds

of years. Basically the process goes:

• Artist completes a clay model.
• Plaster (or gelatine) is applied to the model in sections. This makes it easy to remove each section once it has hardened.
• A layer of melted wax is brushed onto the inside surface of each plaster section. The thickness of this wax layer determined the thickness of the bronze walls of the finished, hollow sculpture. The size of a sculpture usually determines the thickness of its walls. A large work requires thicker walls than a small one.
• The wax-lined plaster sections were then reassembled and filled with a solid core of fireproof material. This is usually a mixture of plaster and silica, or silica and brick.
• Once the core was dry, the plaster sections were removed, leaving the wax surface exposed. Several long metal pins were pushed through the wax into the core, holding it in place.
• Wax rods were attached to the wax layer around the core. These served later as air vents and conduits, or channels, for the molten metal.
• The wax model, along with rods and core, was placed upside down in a container and a mix of plaster and silica was poured around it. This was allowed to harden into a fireproof mold called an investment.
• The investment was heated in a kiln and the melted wax was allowed to run out. It is for this reason that the process is called lost wax. The metal pins inserted earlier maintain the gap between the core and the investment as the wax that previously separated them melted and ran out.
• Molten bronze was poured into the empty space between the inner core and the investment. In this way metal replaced areas that were previously filled with wax.
• The sculpture was taken from the kiln and the inner core and investment removed. The pins, air vents, and conduits were cut off and the surface of the sculpture cleaned and finished.

Casting offers several advantages to the sculptor, not the least of which is the opportunity

to work with a soft, pliable medium to create the original sculpture. By casting, an artist

also has the opportunity to make multiple versions of the original.

5. Assembly (10 minutes)

In the process of assembly, the artist gathers and joins together a variety of different

materials to construct a three-dimensional work of art. Unlike the other sculpture

processes, assembly is a modern technique (show example of Marisol).

Women and Dog, Marisol

Kinetic art is a sculptural form that actually moves in space. This movement continually

changes the shapes and forms that have been assembled to make up the sculpture.

Movement can be caused by such forces as wind, jets of water, electric motors, or the

actions of the viewer (show example of mobile).

Interior, East Wing of the National Gallery of Art, I.M. Pei

6. Closure (2 minutes)

Today’s sculptors, given the advantage of new materials and processes, are creating

artworks that go beyond the wildest dreams of artists just generations ago. No one can

predict what the sculptures of the future will look like. One thing we do know is that they

will continue to record the full range of human experience in ways that are sometimes

shocking, sometimes touching, but always exciting to see, to touch, and to experience.