In a wilderness survival situation, clay can be used to construct bowels, cups, ovenware, and other utensils. It is especially useful when the need for a waterproof container arises. Clay can be found in most environments – near lakes, ponds, river ways, or anywhere the ground has been cleared to reveal the clay base below.
The properties of clay
The main ingredients in primary clay, clay which is found in its original location, are alumina, silica, and water. In secondary clay, clay that has moved and picked up additional minerals, you may also find quartz, mica, and iron.
The properties of clay allow it to harden when heated to at least 1,200 F. This hardening, called firing, makes clay impermeable to water and thus, and excellent material for cookware and storage containers.
The process of collecting, forming, and firing clay is the same for all utensil and tool construction. In the example below, we’ll explain how to construct a bowel from clay.
Remember, when clay is dry, it looks just like ordinary rock. To determine if the material is clay or rock, scrape with a knife. If the material is clay it will flake off easily. When wetted, the flakes should form a dough-like substance rather than dissolve.
When clay is wet, it is hard, slippery, and stays together when scooped up. You should be able to bend a piece of clay without it breaking apart.
When a piece of clay is squished between the thumb and forefinger, it forms a ribbon. Good quality clay will form long ribbons before breaking apart. Scientists use this “ribbon test” to determine the amount of clay content in soil.
Dry the clay
To begin, first dry the clay. Pinch off pieces of clay about the size of a marble and place in the sun for drying. The smaller the pieces, the quicker the clay will dry.
Crush into powder
Once dry, crush the clay into powder. Use a large, flat stone as a base and a smaller stone to crush the clay.
Remove any impurities such as small rocks, sticks, and grass from the powder. The more impurities removed, the higher quality the clay product will be. You can also thoroughly mix the clay powder with a large volume of water and poured through a screen to remove debris. You can alternate between wetting, drying, and powdering the clay several times to filter out impurities.
Create clay “ropes” and stack to create wall
Gradually wet the clay powder by adding a small amount of water while kneading the clay.
Once the clay is wet, ball up a wad and then roll into a “rope” or “pottery coil”.
To create the bottom of the bowel, curl the rope into a tight spiral. Smooth the clay between the spirals to form a smooth, solid, surface.
Make a ring from the rope with a diameter equal to the desired diameter of your container and the same size as the bottom piece. Place the ring on the spiral bottom section. Continue creating and stacking rings on top of each other to form the sides of the bowel. After you place a ring on another, smooth them together to form a smooth, solid side. Add water as needed to allow the clay to be worked.
Fire harden the final product
Once the bowel has been formed, you’ll need to fire harden the final product to make it impervious to water. Build a fire around the pot such that flames run up the sides of the bowel. With a fire ring built around the bowel, push the coals as close to the bowel as possible without touching it.
Allow the fire to burn out and cool on its own. The more gradual the reduction in temperature, the more stable the hardened clay will be. If the fire cools too quickly, the clay will become brittle and will crack and chip easily.
The fire can also be built in a pit. A Dakota Fire Hole works well for retaining heat and the extra airflow allows for much higher temperatures. Alternatively, a teepee fire, with sticks stacked on end around the bowel and meeting above the bowel (a cone shape) also work well. A homemade forge would also work but takes extra time to build.
Clean the final product
Finally, wash the bowel with boiling water.
Potential problems and solutions
If the clay cracks, you can add sand or crushed mussel shells to the mixture to temper it.
Remember too that the clay can be reused. Simply break it back down to powder, add water, and begin again.
Storage of clay
Clay can be stored for later use. Starting with wet clay, spread it onto a canvas or sturdy cloth. Roll the cloth into a roll and wrap with plastic or place in a waterproof bag for long-term storage.