Wednesday, March 9, 2011

Clay - Precious Pots

The children construct and paint miniature clay pots with lids. For ages 6 to 9. Plan 3 to 4 sessions.

  • Introduction to clay slabs
  • Making lids for clay pots
  • Painting clay
  • Working with three-dimensional form
slab, scratch and slip, leather-hard, bisque-fired, lip, underglaze, glaze

Click here for more information on working with clay. Click here to see how guide sticks are used to roll clay slabs.

  • 12- x 18-inch Masonite boards with one side unfinished (one for each child) or canvas to cover the work surface
  • Clayeach child will need two grapefruit-sized balls and one smaller ball. Plan to also have some extra clay available.
  • Clay needle tools
  • Containers with a small amount of slip or water
  • Rolling pins or stiff cardboard tubes
  • Guide sticks (optional, see note below)
  • Underglazesnon-toxic
  • Clear glazenon-toxic
  • Brushes for applying underglazes and glazes
  • Trays and plastic bags for storing and drying the clay
Note: Guide sticks are useful in controlling the thickness of the clay. They need to be the same thickness as the desired slab and can be made using strips of wood, flat rulers, or even strips of cardboard stacked and taped together.

First Session
  • Check the clay several days ahead to be sure it has a good workable consistency.
  • Cover the work area with Masonite boards with the unfinished side up or canvas.
  • Set out one grapefruit-sized ball and one smaller ball of clay for each child, plus a few extra.
  • Set out rolling pins, needle tools, containers of slip or water, and optional guide sticks.
How to Begin
  • Explain that, in the next several sessions, the children will be making miniature clay pots with lids. In this session, they will be rolling slabs, or flat pieces of clay, to construct the pots.
  • Demonstrate how to make a clay slab. If using guide sticks, place one on each side of a clay ball, positioning them so that, when the clay is flattened, the rolling pin will ride on both sticks. Starting from the center of the clay, roll away from yourself with enough pressure to begin flattening the clay. Roll only to the edge of the clay, lift the rolling pin, and return to the center. Roll towards yourself using the same pressure. Repeat these steps, gradually increasing the pressure until the rolling pin rides directly on the guide sticks. As you work, turn the slab over several times to avoid having it stick to the work surface. If working without guide sticks, follow the same procedure, being careful that all parts of the final slab have an even thickness. 
  • Be sure the children understand the scratch and slip method for attaching pieces of clay—scratch the surfaces to be joined, apply a small amount of slip or water, and press the two pieces together. 
  • To make a base for the pot, flatten a small ball of clay into a slab about ⅜ inch thick. Use a needle tool to cut out a shape, such as a circle, rectangle, diamond, square, or heart. To keep the pots miniature, the shapes should be no more than several inches in any direction.
  • For the sides of the pot, press a grapefruit-sized ball of clay into a very fat coil and then roll it into a ¼- to ⅜-inch thick slab, making it long enough to go continuously around the edges of the base. With a needle tool and the straight edge of a ruler or guide stick, trim both sides of the long slab making it no more than three inches wide.
  • Construct the pot by scratching around the top edge of the base, adding a small amount of water and then attaching the long slab along the scratched edges. When the slab meets itself, trim the extra clay and join the two ends by scratching and slipping them very carefully so they will not pull apart while drying. To form corners, as for a square or rectangle, gently pinch the sides into shape.
  • Have the children choose shapes for their pots, roll the slabs, and construct the pots.
Note: Allow the clay pots to harden until they are firm enough that they can be handled without changing their shapes, and then cover them with plastic wrap until the next session.

Second Session
  • Set out one grapefruit-size ball of clay for each child, plus a few extra.
  • Cover the work area with Masonite boards or canvas.
  • Set out needle tools, containers of slip or water, and the clay pots.
How to Begin
  • Explain that the pots are now leather-hard, meaning that they are dried to the point that their shapes cannot be changed without breaking them. In this session, the children will make lids for the pots.
  • Show the children how to make a lid by rolling a slab a bit thicker than the sides of the pot. Gently press the leather-hard pot upside down onto the slab, leaving a slight indentation. With a needle tool, cut along the outside edge of the indentation. Lay this slab aside keeping it face-up. Again press the upside-down pot into the remaining slab, this time cutting slightly inside the inner edge of the indentation. Scratch and slip both pieces and attach the smaller slab face-up to the center of the larger slab. This will make an insert that will keep the lid firmly on the pot. 
  • The remaining clay can be used to make optional handles or embellishments for the lids. Explain that in order for each lid to become an integral part of its pot, its design needs to coordinate with the pot; such as an octopus handle for a pot painted like an ocean, a heart handle for a heart-shaped pot, or ears for a pot painted like an animal.
  • Have the children make lids for their pots and attach any handles or embellishments.

Note: Put the lids on the pots and wrap them with plastic, drying them by slowly loosening the plastic. When completely dried, bisque-fire the lidded pots in a kiln.

Third Session
  • Set out the bisque-fired pots.
  • Set out brushes and underglazes
How to Begin
  • Explain to the children that the pots have been fired for the first time, or bisque-fired, in a kiln. They are fragile and must be handled very carefully. In this session, the children will be adding color to the pots using underglazes.
  • Demonstrate how to apply the underglazes. The clay is now very porous, so the underglazes will dry quickly. To avoid scrubbing and to cover all areas of the pots, dip the brushes in the underglaze often and dab into cracks or rough areas on the surface, brushing away any puddles that may occur.
  • The children should first paint the base colors of underglaze on the outsides of the pots, and then paint the insides of the pots. This will allow the outsides of the pots to dry enough to add designs.
  • Have the children paint their pots, reminding them to coordinate the designs on the lids with the designs on the pots.
Note: Low-fire the underglazed pots before applying clear glaze. Since glaze on the lips of the pots will cause the lids to stick to the pots in the glaze-firing, consider having an adult instead of the children apply the clear glaze, eliminating the need for a fourth session.

Fourth Session
  • Set out clear glaze and brushes.
  • Set out fired underglazed pots and lids.
How to Begin
  • Tell the children that they will be applying a clear glaze to their pots which will give the pots a hard protective surface. Explain that the 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.
  • Explain that when the glaze melts, it becomes sticky and attaches itself to the surface. Therefore, glaze should not be put on the bottom of the pots which will cause them to stick to the kiln shelf. Since the lids will be fired on the pots, no glaze should be put on the undersides of the lids or on the lips, or top edges, of the pots.
  • To avoid putting on too much clear glaze, which will cause the colors to become cloudy after firing, be sure the children understand that the glaze will look transparent when it is first applied. As it dries it becomes opaque. (The number of coats needed varies according to the glaze instructions, but usually one or two coats are sufficient.)
  • Have the children apply glaze to the insides and the outsides of the pots, avoiding the lips, and to the tops and sides of the lids, avoiding the undersides.
Note: When the pots are dry, glaze fire them in a kiln.

  • One of the challenges of working with clay slabs is joining them so they will not split during the drying process. This project has only one seam, making it a good introduction to building with slabs.
  • In most cases, water works as well as slip for joining pieces of clay and is less messy.
  • It's essential to emphasize and monitor the safe use of clay needle tools.
  • Remind the children how easily leather-hard and bisque-fired clay can be broken.
  • Uncomplicated shapes are easier to work with when making lids to fit the pots.
  • For even shrinkage, the pots should be dried and fired with the lids on them. If a lid sags when placed on the pot, put newspaper inside of the pot to support the lid until it becomes leather-hard.
  • Aamaco's Velvet underglazes do not need a clear glaze on top of them, so they work well for the insides of the pots and the undersides of the lids.
  • If time is limited, encourage the children to paint the insides of their pots with a single color so that they can concentrate on designing the outsides of the pots.
  • Discuss the process used to roll the clay slabs.
  • Are the walls of the pots evenly thick?
  • Do the designs on the lids coordinate with the designs on the pots?
What the children might say...
  • The clay keeps sticking to my rolling pin.
  • Part of my slab got very skinny.
  • I'm finished rolling my slab, but I can't lift it because it is stuck to the board.
  •  My lid is backwards and won't fit into my pot.
  • I'd like to make my pot in the shape of a star.
  • I want the inside of my pot to be shiny all over.
What you might say...
  • Start rolling your slab at the center of the clay. Lift the rolling pin and return to the center each time. If you roll back and forth, the clay will stick to the rolling pin.
  • If you rolled your slab too thin, fold it in half and try again.
  • Remember to turn your clay over several times while you are rolling your slab. This will keep it from sticking to the work surface. If you forgot, carefully peel up the edge and the rest of the slab should lift off easily.
  • When you cut out the slab for your lid, be sure to keep it face-up while you add the insert. This way it will fit your pot when you turn it upside down. If your lid is backwards, take the insert off and attach it to the other side of your lid.
  • A star shape is a nice idea, but you will have to be especially careful when cutting out the insert and fitting it on the slab for the lid.
  • If there is any glaze on the areas where the lid touches the pot, it will stick to the pot. Therefore, the glaze can only be applied to the areas where the lid does not touch the pot.
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