How to Make an Urchin Bowl From Clay

The sea urchin's spines are re-created as the texture on an urchin bowl.

Urchin bowls take their inspiration from sea urchins, displaying a spiny outer texture on a traditional bowl shape. These vessels can add a dramatic and ocean-themed accent to your living space. You can craft your own urchin bowl using ceramic clay if you have access to a pottery kiln to fire your project once you are finished. A fired clay is more durable than clay that does not undergo this baking process. The clay also can sealed with glaze before you fire it if you want the bowl to be able to hold water.

Things You'll Need

• Canvas
• Fork
• Pint jar with lid
• Spray bottle
• Plastic bag
• Glaze
• Paintbrushes
• Square board

Instructions

Making Slip

1. Remove a piece of clay about 3 inches in diameter from its storage container.

2. Tear the clay into dime-size pieces, and place the small pieces of clay into the pint jar.

3. Add water until the clay bits are covered by the water.

4. Let the jar of clay and water stand, periodically shaking it, or stirring it, until the clay dissolves in the water. The texture of the mixture should be similar to mud, although runnier.

5. Add more bits of clay or water to the mixture until you achieve the correct consistency. This clay and water mixture is called "slip" and is used in ceramics as a glue to bond two pieces of clay together while they are moist.

Making the Bowl

1. Remove a piece of clay from the storage container that is about 4 inches in diameter, and roll the clay around in your hands to form a ball.

2. Press your thumb into the ball of clay to form a dip in the middle of the ball, but do not press all the way through the ball.

3. Leave your thumb inside the dip in the ball while pressing the flats of your fingers along the outer sides of the clay, pressing and shaping the sides into a bowl shape. Continue this process around the outsides of the bowl until the thickness of the clay is between one-eighth inch and one-quarter inch.

4. Set the bowl on the piece of canvas to create a flat bottom to the bowl. Press the bottom of the bowl into an even thickness that is no thicker than one-quarter inch. Clay that is any thicker can potentially explode while the ceramic bowl is baked -- or "fired" -- in the kiln.

5. Mist the bowl thoroughly with water from your spray bottle, and cover it tightly with a plastic bag while you are not working on it. This keeps the clay from drying out, which can cause the clay to become less flexible or even crack.

Attaching the Spines

1. Remove a piece of clay from the storage container, and tear pieces from the clay that are about the size of a nickel.

2. Roll the nickel-size pieces of clay in your fingers to form elongated cones. The cones should not exceed 2 inches, otherwise they will be too brittle.

3. Flatten the ends of the cones with your finger, and scrape the bottoms with the fork. This is called "scoring" the clay, and is a method used in ceramics to attach one piece of clay to another.

4. Remove the bowl from its plastic wrapping, and score the entire outside of the bowl with the fork. Make crisscrossing scores in the clay.

5. Use a paintbrush to add a thick coat of slip to the scored bottom of each spine, and firmly press one of the spines onto the sides of the bowl. Blend the base of the cone-shaped spine onto the bowl's surface. Repeat this step until the bowl's exterior is completely covered with spines.

Glazing and Firing the Bowl

1. Place the urchin bowl on a square piece of board. This gives you a stable base on which to carry your bowl and allows you to turn the bowl without touching it.

2. Set the bowl aside to dry. Clay can take anywhere from a few days to a week to dry completely. Once the clay is thoroughly dry, it is called "greenware" in ceramics, and is very delicate.

3. Use a paintbrush to paint the inside and outside of the bowl with glaze. Glaze is a special kind of paint used in ceramics, and is made from ground metals and minerals. Try to evenly apply each coat of glaze.

4. Apply a second layer of glaze to the bowl with a paintbrush, allowing each coat of glaze to dry before adding the next coat. You will need to use between two and four coats of glaze to ensure that the inside is completely covered.

5. Take your bowl to a kiln to have it fired. Your bowl will be much stronger once it is fired, and will be able to hold liquids. Fired clay is called "stoneware" in ceramics once it reaches this stage.

Tips & Warnings

• A university or a local artist's cooperative will either be able to give you access to their kiln or be able to direct you to a place where you can have your urchin bowl fired. This may involve a fee, since the firing process consumes a significant amount of fossil fuel to reach the high temperatures necessary to harden clay.

• Use care when handling your dried "greenware" urchin bowl before it is fired, as the clay becomes highly brittle.

References

• Apartment Therapy: Urchin Bowl
• Supermarket: Large Urchin Bowl from Heather Knight
• Make a Clay Bowl
• Attaching Clay Parts

Resources

• Pottery Tips and Techniques Attaching Clay Parts