How to Make Pottery From Natural Clay

Hand building with natural clay is fun

Natural clay comes from stream beds, lake shores and even from your own backyard, depending on where you live. When wet, it is a gushy, but pliable, form of dirt; when dry, it is rock hard, but crumbly.

Processing natural clay will take more than one day and will require table and floor space. You will probably want to do this somewhere like the garage or basement instead of the kitchen, as this is a messy and long term project. However the end result is worth the wait.

Things You'll Need

• Clay dug from the ground
• Newspaper or kraft paper
• A rubber hammer
• A piece of heavy canvas
• A wire sieve or window screen
• A siphon tube, cup or ladle
• Appropriately sized containers to put the clay into
• A large putty knife
• A wire rack (optional)
• A large amount of surface space (table or counters).
• Clean sand or commercial ball clay, powdered or processed.
• A wedging board (or a board to wedge on)
• A cutting wire.

Instructions

Cleaning the Clay

1. Spread the clay out on a clean sheet of paper covering a counter, table or a supported window screen, to allow air flow from all sides. Let the clay dry out completely.

2. Wrap it in a piece of heavy canvas and pound on the canvas to break it up. Pound the clay until it is powdered. Remove rocks, sticks and other debris.

3. Sift the powdered clay through a sieve, or window screen, into a container double the size you would need to hold the current amount of powdered clay. Remove any extra unwanted debris, such as pebbles or small bits of extraneous matter.

4. Pour water into the clay. Make sure there is enough water to cover the clay entirely. Let the clay sit for a couple of days without stirring or disturbing it. If the clay has soaked up all the water, add enough to cover the top of the clay by about 1 inch. This will allow all of the clay to become soft and mushy, breaking up any hard chunks.

   Leave it alone until the clay has settled entirely to the bottom and is thoroughly "slaked."

5. Stir the clay so that it becomes about the consistency of whole milk or cream. This is referred to as "slip."

6. Strain the slip through a sieve or window screen into another large container. This is the final "cleaning" of the clay, ensuring that there is no unwanted debris in the clay.

7. Allow the clay to settle to the bottom of the container so that there is clear water on top of the clay and the clay is a chunk of mush below the water's surface.

8. Siphon or dip the water off of the top of the clay.

Processing the Clay

1. Take the clay out of the container and spread it out on the piece of canvas so that the clay is 2 or 3 inches thick. The clay will be very mushy, about the consistency of frosting. Smooth the top of the clay so that it dries evenly.

2. Allow the clay to dry out to the point where it holds together when you try to pick it up. You can assist the clay's drying by putting the clay on the canvas onto a wire rack or using a fan set on low. The clay will be ready when its consistency is a little wetter than regular clay.

3. Take the edge of the canvas that the clay is on and flop it over onto the clay, so that the clay has folded onto itself. Pull the canvas away from the clay. A good test of clay readiness is if the canvas pulls away easily.

4. Roll the clay up into a big tube to get it off of the canvas. Alternatively, if the clay is not coming up easily, use a large putty knife to scrape the clay off of the canvas.

5. Put the clay onto the wedging board. A wedging board is commonly a metal table top, a slab of rock or a wooden board covered in canvas.

6. Take the cutting wire and cut the clay into smaller chunks. A cutting wire is usually a length of wire with a small piece of wooden dowel on either end, but can be as simple as a long piece of fishing line.

7. Take the smaller chunks of clay and throw them onto the wedging board. This helps to eliminate air bubbles and helps the clay to dry out to a more elastic consistency.

   Cut the clay and then throw it onto the board several times until the clay feels pliable.

8. Wedge the clay. This is similar to kneading bread dough -- pushing the lump of clay forward and pulling it back. However the ideal is to get a spiral pattern going, making the lump of wedged clay look a bit like a seashell.

9. Once the clay is wedged and feels pliable, it is ready to be made into pots, using any method of hand building or throwing you choose.

Tips & Warnings

• To make the clay more elastic, during the wedging process you can spread a little bit of clean sand onto the wedging board and it will get mixed in as you wedge the clay. Add very small amounts of sand at a time, allowing it to mix in thoroughly. Too much sand will dry out the clay and make it crumbly and unusable.

• This mixing process can also be done with powdered ball clay, the standard clay powder that gets mixed up for commercial clays.

• Alternatively, you can take regular, prepared commercial clay and add it to the cutting and slapping process. All of these additives help make the clay more elastic. Choose only one additive for your clay mixture.

• Processing and working with clay should be done in a fairly well ventilated and easy to clean area. This is a dusty and a messy process.

• Breathing in large amounts of clay dust is unhealthy.

• Make sure that you completely cleaned the clay to remove any foreign objects from it, including rocks, plant material and sticks. Any remaining debris could leave an air bubble when it burns away in the firing process, causing the pot to break.

References

• Goshen College Art Department: Rework Clay, Dig Your Own Clay & Fire Without A Kiln
• Fire How: How to Prepare Natural Clay for Pottery
• Atomic Shrimp: Making Pots From Natural Clay