The clay that is used to make terracotta objects or for other artistic projects can be easily obtained from the earth that is in your own garden; it is a long but simple process. All you need are some containers, earth, water and a cloth; in this way, you can separate the clay from the sediments and make it thicken.
Part 1 of 3: Mix the Mud
Step 1. Collect some soil
In theory, you should take the one that is under the surface layer; the latter is 5 to 20 cm thick and contains a high concentration of contaminants. By discarding topsoil you can get rid of organic residues, such as live plants, roots and insects. The more earth you take, the more clay you get.
Step 2. Transfer the soil to a container
The size of the container depends on how much soil you are using; fill it about two thirds of its capacity. Try to avoid those that have a narrow opening, similar to the bottleneck, otherwise you have a harder time emptying them of contents during the later stages.
To get rid of the residue, you can sift the earth before putting it in the bowl, although this is not a mandatory step
Step 3. Add the water
You can use plain tap water and mix it thoroughly with the mixture; you should get rid of all the lumps and get a uniform mush.
Part 2 of 3: Separating the Clay from the Sediments
Step 1. Let the mixture stabilize
The clay separates from the sediments and remains in suspension in the water floating above the residues to be discarded; be careful not to shake the container or mix the sediments at the bottom.
Step 2. Pour the clay water into another container
Proceed with caution so as not to transfer the debris as well; when the latter approach the edge of the container, stop pouring the water and get rid of the sediments.
Step 3. Repeat this process four or five times
Add the water, mix the mixture, let it rest and pour the clay water into a new container; with each step the clay becomes purer and purer. In theory, you should continue like this until you find no more sediment on the bottom.
Part 3 of 3: Thicken the Clay
Step 1. Let the clay separate from the water
Since the material is suspended in water and is not highly soluble, it settles on its own to the bottom when allowed to stand. The clayey water must remain undisturbed for at least 24 hours; the mixture splits into two distinct layers and you can realize this phenomenon because the water becomes transparent again.
If you still notice sediment under the clay layer, repeat the steps described above to remove it
Step 2. Pour the water
When the clay layer approaches the edge of the container, stop; the material is soft and waterlogged, if you throw it away you have to start over.
Step 3. Wait for the clay to settle
As it settles on the bottom, another layer of water forms on the top; get rid of the liquid again by stopping as soon as you see the material approaching the rim of the container.
You can repeat the procedure until the surface water layer no longer forms
Step 4. Filter the clay through a cloth
Stretch the fabric over a bowl and pour the flowable material over it. The cloth should be large enough to wrap all the clay in the container and act as a bag; then close the "bundle" with a piece of string, creating a sort of clay ball inside the fabric.
- Any type of cloth is fine. You can use an old shirt or sheet that you no longer use; But choose a fabric that you don't mind getting dirty.
- You can divide the clay into several cloths to speed up the hardening process.
Step 5. Hang the bundle
In this way, the water can drip off through the fabric; as the liquid escapes, the clay becomes harder and harder. It takes two or three days to complete the process.
- Hang the bundle in an area where dripping water cannot cause damage; you could tie it to a tree branch or porch.
- After a couple of days, check the consistency of the clay. You need a material of different density according to the various artistic projects you want to make; if you need harder material, just let it hang longer.