How to Make Moist Clay

Clay is extracted from soil that is located near a water source.

Moist clay is available in art stores and many potters or amateur artists opt to buy the material for their convenience. However, you can make your own clay and prepare it so it is most suitable for your hand-building, throwing or slip-casting projects. Clay is basically made up of minerals such as alumina, silica and iron oxide, which are mixed with water. These minerals are found in soils that are close to a water source. Prepare your clay with soil and water and dry your clay to the desired plasticity on plaster blocks.

Things You'll Need

• Soil rich in clay
• Buckets
• Wooden stick
• Sand
• Mesh screen or sieve
• Blocks of plaster or plaster molds

Instructions

1. Dig for clay in soil that is close to a water source such as a river, ocean or stream. Clay is found in many colors such as red, which contains a high amount of iron oxide, gray or white, which is also known as kaolin.

2. Gather a large bag of clay and avoid pebbles or rock particles, because these can't be used in making clay.

3. Fill a quarter of a bucket with water and add the clay. You need one part water and two parts clay, so you can measure the amount of clay you have in another bucket. Mix with a wooden stick or a kitchen utensil for 15 to 20 minutes.

4. Allow the clay to sink to the bottom of the bucket overnight.

5. Apply a mesh screen on an empty bucket and pour the clay through the screen. This eliminates debris and small rocks from your clay. Small rock particles may cause your pottery pieces to explode while in a kiln.

6. Allow the clay to sit in the bucket for another 12 hours. The clay is heavier, so the water remains on the surface. Get rid of the water from the clay and you obtain a liquid clay, which may be suitable for slip-casting projects. Store this liquid clay in airtight container. If you want clay for hand-building or wheel-throwing projects, you need to dry the clay.

7. Pour the liquid clay on plaster molds or blocks and allow the clay to dry until it can be shaped into slabs or coils. Plaster quickly absorbs the water. Dry the blocks of plaster before using them for pressing or making clay.

Tips & Warnings

• Look for several sources of clay in your area. Gather only small amounts of clay at a time and test the quality of clay to decide on the best source.

• The type of clay you obtain (e.g., stoneware, earthenware) depends on the composition of the soil you collect. Add silica or iron oxide to your clay and use a mixer to obtain a homogeneous paste.

• Prepare your own plaster blocks using cardboard boxes and make the blocks at least 3 inches in thickness.

References

• The Encyclopedia of Earth; Clay; 2008
• Pottery the Art: Mining Indigenous Clay