Wednesday, January 6, 2010

Clay – Coil Pots with a Twist

The children make clay pots using rolled coils of clay and experiment with the coils moving in different directions. For ages 6 to 13. Plan 3 to 4 sessions.

KEY IDEAS
  • Learning how to make and use clay coils
  • Working with three-dimensional form
  • Applying underglazes and glazes
LANGUAGE
coil, scratch and slip method, greenware, bisque ware, lip, underglaze, glaze

RESOURCES
Click here for more information on working with clay. The materials and processes used in this project are described in detail.

YOU WILL NEED
  • 12- by 18-inch Masonite boards (one for each child) or canvas to cover the work surface
  • Clay, two grapefruit-sized balls for each child
  • Clay needle tools or tenpenny nails
  • Containers with a small amount of slip or water (one for every two children)
  • Underglazes in a variety of colors (non-toxic)
  • Clear glaze (non-toxic)
  • Brushes for applying underglazes and glazes
  • Plastic bags and trays for drying the clay projects
THE PROJECT
First Session
Preparation
  • Check the clay several days ahead to be sure it is of good workable consistency.
  • Wedge the clay into grapefruit-sized balls, planning one for each child. (A second ball of clay will be needed in the next session.)
  • Cover work area with individual Masonite boards or canvas.
  • Set out clay balls and needle tools or ten-penny nails.
  • Set out containers with a small amount of slip or water. 
How to Begin
  • Explain to the children that they will be using the next two sessions to build clay pots. Warn them that this project will not be completed for several weeks, since the clay must be dried slowly and fired in the kiln several times.
  • The children should know that before clay projects are fired in the kiln, they are referred to as greenware. After the first firing, they are referred to as bisque ware. After painting the bisque ware, it is put in the kiln again for a final firing. 
Rolling the coils
  • Show the children how to make coils. Break off a large chunk of clay and roll it between your hands to form a thick snake-like shape. Put the “snake” on a flat surface. Starting with your fingertips, roll the clay using your whole hand down to the bottom of the palm and back to the fingertips. Repeat this motion moving up and down the coil, gradually increasing pressure until the coil is about a half-inch in diameter. If the thickness of the coil is uneven, place your hand over the thicker spots and roll with a little pressure.
  • Have the children practice rolling coils that have an even thickness and are approximately a half-inch in diameter.
Building the pot
  • Show the children how to make a base for their pots by flattening a piece of clay to a half-inch thickness with a diameter larger than the planned bottom of the pot.
  • The first coil added to the base must be attached using the scratch and slip method. With a needle tool, scratch the clay around the top of the base about half an inch inside the edge. Explain to the children that this half-inch of clay will prevent the pot from sagging while the clay is soft, and will be trimmed away after the clay begins to harden. Attach the first coil along the scratched area of the base with a small amount of slip or water. It is not necessary to scratch the coil if you gently blend a small amount of clay from the coil into the base.
  • Show the children how a coil placed directly on top of the coil below it will make a straight-sided pot. If the coil is placed slightly on the outside edge of the coil below it, the pot will gradually flare open. If the coil is placed on the inside edge of the coil below it, the pot will begin to close.
  • As each coil runs out, attach a new coil directly against the end of the previous coil and blend them together with your fingers. After the first coil is attached to the base, it is not necessary to use the scratch and slip method to attach the rest of the coils. Inside the pot, join the coils by gently pushing a small amount of clay from the top coil into the coil below it. Turn the pot while joining and smoothing the coils. Keep one hand cupped along the outside of the pot to support its shape.
  • After adding two or three layers of coils to their bases, the children should then begin making their coils move in different directions, such as in zigzags, circles, vertical lines, spirals, etc. Be sure the children understand that wherever a coil touches another coil, the two coils must be joined together or the pot will fall apart as it dries.
  • Have the children make the bases for their pots and begin to experiment with different ways to use their coils while building their pots. 
Note: Store the unfinished pots on trays and cover them with plastic to keep them moist. Before the next session, expose the pots to air long enough to let the clay harden slightly. This will prevent the pots from sagging under the weight of the fresh clay to be added. The amount of drying time will depend on the wetness of the clay and the humidity in the air. 

Second Session
Preparation
  • Wedge the clay into grapefruit-sized balls, planning one for each child.
  • Cover work area with individual Masonite boards or canvas.
  • Set out clay balls and needle tools or ten-penny nails.
  • Set out containers with a small amount of slip or water.
  • Set out slightly hardened pots.
How to Begin
  • Explain to the children that they will be trimming the extra clay from the base of their pots and then completing their forms with more coils. Be sure they understand that their pots must be handled very carefully.
  • Demonstrate how to trim the extra half-inch of clay from the base of the pot. With the needle tool slanted slightly inward, carefully cut the extra clay from around the base and smooth the rough edges with your finger.
  • The first new coil added must be attached to the drier clay using the scratch and slip method. The rest of the coils can be joined by pushing some of the clay into the coil below it.
  • Explain that the last coil on the top of the pot is called the lip, and it needs to be smoothed carefully to give the form a completed look.
  • Have the children trim the extra clay from the bases of their pots and begin building their forms with more coils. Remind the children to experiment with their coils moving in different directions.
Note: Cover the pots with plastic, gradually loosening it to dry the pots very slowly. Then bisque fire them in a kiln.

Third Session
Preparation
  • Set out bisque fired pots.
  • Set out brushes and a variety of underglazes.
How to Begin
  • Explain to the children that they will be adding color to their bisque ware with underglazes, which are paints for clay. Warn the children that bisque ware is fragile and must be handled very carefully.
  • Demonstrate how quickly underglazes dry when applied to bisque ware. Explain to the children that they should dip often into the underglaze and dab into any cracks or rough areas on the clay surface. Since two coats of underglaze are needed, the children should paint the inside of their pots first. While they paint the outside of the pots, the inside will dry enough to apply the second coat, followed by a second coat on the outside.
  • Explain that coils are hard to paint individually, so the children should choose a single color of underglaze. This will also keep the emphasis on the movement of the coils.
  • Have the children apply two coats of underglaze to their pots. Allow the pots to dry overnight.
Note: Although clear glaze can be applied directly over the dried underglaze, it is better to bisque fire the pots a second time. This will avoid rubbing off any of the underglaze and give the pots a stronger protective coating.

Final Session
Preparation
  • Set out clear glaze and brushes.
  • Set out dried or fired underglazed pots.
How to Begin
  • Explain to the children that they will be applying glaze to their pots which will make them shinier and stronger. Tell them that the clear glaze will cover up the underglaze colors temporarily. When the clay is fired in the kiln again, the glaze will melt and turn clear, allowing the colors to show through.
  • Show the children how the clear glaze looks transparent when it is first applied and still wet, but dries very quickly and becomes opaque. (The number of coats needed varies according to the glaze instructions, but usually one or two coats are sufficient.)
  • Warn the children to avoid getting glaze on the bottom of the bisque ware because it will stick to the kiln shelf during firing. If glaze does get on the bottom, wipe it off with a damp cloth before putting it in the kiln.
  • Have the children apply the glaze to the inside and the outside of their pots.
Note: Let the pieces dry and then glaze fire them.

NOTES
  • This project is better to do with children who already have some experience working with coils.
  • Children’s hands are small, so they need to use the whole length of their hands to roll their coils. 
  • To scratch and slip each added coil becomes too tedious and often the scratch marks show on the outside of the pot. Instead, carefully blend the coils on the inside of the pot.
  • It's important to emphasize and monitor the safe use of needle tools.
  • Don't build the pots too high in the first session. The base needs to harden a bit so it won't sag under the weight of the wet clay.
  • I give individual help to younger children as they trim the base of their pots. 
  • Warn the children to handle their bisque ware carefully.
  • To avoid putting on too much glaze, be sure the children understand that the clear glaze will look transparent until it dries.
LET’S TALK ABOUT OUR WORK
  • Discuss the various ways the coils have been used.
  • Are the coils joined and smoothed on the insides of the pots?
  • Are the lips of the pots carefully finished?
What the children might say...
  • My coils keep getting too skinny.
  • I’m going to see how long I can make my coil.
  • Uh oh! I tried to change the shape of my greenware and it cracked.
  • I want to use all the colors on my pot.
What you might say...
  • If your coils are too thin, put them aside and try again. While rolling your coils, check them often and stop rolling before they become too thin.
  • Coils are easy to join together on your pot, so it is more important to roll strong coils with even thickness rather than long coils.
  • Remember that once the clay starts to dry, you cannot change its shape. Let’s put a “band-aid” on the cracked area using slip and a piece of wet paper towel. This may help the clay join together again.
  • You as the artist can decide what color or colors to use, but remember that if the design becomes too busy, we won’t notice the wonderful movement of the coils in your pot. 
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