Can I Let Natural Clay Air Dry?

What is natural clay?

Natural clay is clay that is found in nature and has not been chemically treated or altered. It is composed mainly of minerals like silica, alumina, and iron along with trace amounts of other elements. The most common types of natural clay include kaolin, bentonite, illite, and smectite clays (1).

There are many different types of natural clays that can vary in color and mineral composition:

• Kaolin clay, also known as China clay, is very gentle and absorbs impurities. It comes in white, red, pink, and yellow shades (2).
• Bentonite clay contains high amounts of silica and absorbs oils. This clay has a grey/cream color (3).
• Illite clay contains silica, iron, and magnesium. It has a light grey/beige appearance.
• Smectite clay, including montmorillonite clay, has a high absorption capacity. The color varies from green to beige (4).

Natural clays are formed from the chemical weathering and erosion of rocks over time. They accumulate in soils and sedimentary deposits and can be mined from open-pit mines, underground mines, and quarries (5). The largest deposits of kaolin clay are found in tropical and subtropical regions, especially in Brazil and Indonesia. Bentonite deposits are located mainly in Wyoming and Montana in the US. Illite and smectite clays have widespread natural occurrence around the world.

References:

(1) https://www.ecco-verde.com/info/beauty-blog/clay-1

(2) https://www.researchgate.net/figure/Major-groups-of-clay-minerals_tbl1_306080559

(3) https://www.sciencedirect.com/science/article/pii/S1878535223007104

(4) https://www.sciencedirect.com/science/article/pii/S1878535223007104

(5) https://www.sciencedirect.com/science/article/pii/S1878535223007104

Benefits of natural clay

Natural clay has several benefits that make it a popular choice for crafters and artists. Some of the key benefits include:

Absorbent properties: Natural clay is very absorbent, meaning it can soak up water and oils easily. This makes it moldable and flexible to work with. The absorbency also allows clay to draw out impurities from skin when used topically.

Moldability: As mentioned above, the absorbent nature of natural clays like bentonite or kaolin clay allows them to become pliable and moldable when mixed with water. This allows easy shaping and sculpting of clay.

Non-toxic and natural: Natural clays are derived from the earth and do not contain synthetic chemicals, making them non-toxic. Many clays like bentonite clay are edible and safe to ingest. Topically, they are gentle enough for sensitive skin.

Sources:

https://www.euphoricherbals.com/blogs/blog/9-benefits-of-clay-for-skin-health-types

https://mundaybodycare.com/blogs/a-case-of-the-mundays/natural-clay-benefits

Challenges of air drying natural clay

Air drying natural clay presents some challenges compared to other drying methods. The main drawbacks are that air drying takes longer, the clay can crack as it dries, and it needs a dry environment.

Air drying clay relies solely on evaporation, so it takes much longer for the moisture to fully leave the clay compared to using an oven or heat source. Complete drying can take 24 hours or more depending on factors like clay thickness and humidity. The slower drying time means projects take longer from start to finish (Source).

As the clay slowly dries, it can start to crack or become misshapen. This is because the moisture leaves unevenly, causing stress fractures in the clay. Cracking is a common problem with air drying that requires care to prevent. Using certain techniques when sculpting and drying can help minimize cracking (Source).

Air drying also relies on having a dry environment. Humidity in the air counteracts the drying process. Damp, humid conditions will prevent the clay from properly hardening. It’s important to dry clay in a warm, dry indoor area for best results.

Tips for air drying clay

To help ensure air dried clay dries properly without cracking, here are some useful tips to follow:

Knead the clay thoroughly before shaping to remove any air bubbles that may cause cracking as it dries. Work the clay until it is soft and pliable with no visible air pockets. According to Gathering Beauty, kneading for 5-10 minutes helps prevent cracking and makes the clay easier to shape.

Shape pieces while the clay is still moist and workable. Allowing the clay to dry out too much before shaping can lead to cracking. For intricate shapes, keep unused clay wrapped in plastic to prevent premature drying.

Allow clay sculptures to dry slowly in a dry, room temperature environment out of direct sunlight. Drying too quickly can cause cracking. Placing pieces on a drying rack allows air circulation all around. According to Susie Benes, maintaining a consistent environment is key for minimizing cracking and warping.

Alternative Drying Methods

If you don’t want to wait for natural clay to air dry, there are a few alternative drying methods you can use to speed up the process:

Oven Drying

One of the fastest ways to dry natural clay is in the oven. To oven dry clay:

• Form your clay pieces and allow them to air dry slightly until they are damp but firm.
• Place the clay on a cookie sheet or baking dish lined with parchment paper.
• Bake at 200°F for 2-4 hours. Check frequently until completely dry.
• Allow the clay to cool completely before handling.

Oven drying works well for most types of natural clay. Just be careful not to over-bake the clay or it may scorch or crack.

Microwave Drying

Another fast option is microwave drying. To microwave dry clay:

• Shape clay pieces and allow to air dry until damp but firm.
• Place clay on a microwave-safe plate or dish.
• Microwave for 1-2 minutes at a time until dry, checking frequently.
• Allow clay to cool before handling.

Microwaving can speed drying time to just 10-15 minutes. But take care not to over-microwave or the clay can crack from uneven drying.

Freeze Drying

Freeze drying clay works by freezing the clay and then allowing the frozen water to sublimate off as it thaws. To freeze dry:

• Shape clay pieces and allow to air dry slightly until damp but firm.
• Place clay in freezer overnight until completely frozen.
• Take frozen clay out and allow to thaw and dry completely at room temperature.

Freeze drying can take 1-2 days, but causes less cracking than fast oven or microwave drying methods.

Preventing cracking

Cracking is a common issue when working with air dry clay because it shrinks and contracts as the water evaporates. However, there are some techniques you can use to help prevent cracks from forming:

Control the drying speed. Letting clay dry too quickly can cause cracking. Air dry clay dries from the outside in, so the outer layers contract faster than the inner moisture can evaporate. To slow down drying, store projects in an airtight container or plastic bag. You can also wrap them in a damp cloth. Just be sure not to trap moisture against the surface.

Reinforce clay with other materials. Adding items like wire, foil, or fabric mesh creates a support structure inside the clay as it dries. This helps maintain structural integrity and prevents cracking. You can also cut or score lines partway through thicker pieces before drying.

Seal finished pieces with oil, glaze, or varnish. This creates a moisture barrier and controls the evaporation rate from the surface. Acrylic mediums work well for sealing air dry clay. Just brush or spray it on according to manufacturer directions. Let the sealer fully cure before exposing clay projects to air.

For minor cracks, moisten the surface and massage clay back together. Use slip (liquid clay) on joints to “glue” pieces together. Repairs blend easily since the clay remains workable until it fully dries.

With careful drying and a few strengthening techniques, you can create durable air dry clay projects with minimal cracking issues.

Uses for Air Dried Clay

Air dried clay is highly versatile and can be used for a variety of applications and crafts. Some of the most common uses for air dried clay include:

Sculptures

Air dried clay is an excellent medium for creating sculptures, figurines, and 3D artwork. The clay maintains its shape as it dries, allowing artists to create detailed sculptures with crisp edges and intricate textures. Many hobbyists enjoy sculpting animals, characters, abstract shapes, and more out of air dried clay (Source). Sculptures make great gifts, collectibles, or home decor items.

Pottery

Simple pottery items like cups, bowls, vases, and pots can be shaped from air dried clay. The finished pieces will be lightweight yet sturdy. Air dried clay pottery is often decorated with paints, glazes, stamps, or carvings after drying. Creating pottery is an engaging hands-on activity for both adults and kids (Source).

Jewelry

Jewelry makers can craft custom pendants, beads, buttons, and embellishments from air dried clay. The clay can be shaped into intricate designs and painted or sealed for a glossy finish. Air dried clay jewelry components add unique, handmade flair to necklaces, bracelets, earrings, and more (Source).

Storing air dried clay

Properly storing your finished air dried clay pieces is important to prevent cracking, drying out, or becoming moldy. The key things to do are:

• Store in a cool, dry place away from direct sunlight or heat sources. Temperature fluctuations can cause cracking. [1]
• Seal air dried clay in an airtight plastic container or bag. This prevents moisture loss. [2]
• Use a desiccant like silica gel packets inside the sealed container to absorb any excess moisture and prevent mold growth. [1]

With proper storage techniques, air dried clay sculptures and projects can last for years. Just be sure to check periodically for any signs of cracks or mold.

[1] https://www.susiebenes.com/blogs/airdryclayart/storing-air-dry-clay

[2] https://www.gatheringbeauty.com/blog/how-to-store-air-dry-clay

Safety considerations

When working with air dry clay, there are some safety precautions to keep in mind. The main concern is the dust produced when sanding dried pieces. Air dry clay contains silica dust which can be harmful if inhaled (Source). When sanding air dried clay, be sure to work in a well-ventilated area and wear a protective mask to avoid breathing in dust particles. It’s also important to thoroughly clean your work area after finishing sanding using a wet cloth or vacuum with a HEPA filter.

In addition to sanding dust, general cleanliness when working with clay is advised. Wash your hands after handling clay and avoid touching your eyes or mouth before washing up. Clean spills right away to prevent stains or slipping hazards. Keeping your studio tidy can help minimize exposure to clay dust.

While air dry clay is non-toxic, it’s not food-safe so avoid any direct contact with food or drinks (Source). With some basic safety practices, air dry clay can be used safely by artists of all ages.

FAQs

Here are some common questions and misconceptions about air drying clay:

How long does air dry clay take to dry?

Air dry clay dries through evaporation, so drying times can vary greatly based on factors like temperature, humidity, clay thickness, and air circulation. In general, expect air dry clay sculptures to dry in 24-72 hours.

Can you speed up the drying process?

There are a few tricks to dry air dry clay faster: work in a warm, dry area with plenty of airflow, use a fan directed on the clay, keep clay sculptures hollow to allow airflow inside, use thin layers of clay, and avoid damp conditions that slow evaporation.

Does air dry clay shrink when drying?

Yes, air dry clay shrinks slightly during the drying process, similarly to polymer clay. Expect up to 10% shrinkage. Allow for this in your original sculpture size and proportions.

Can you revive dried out clay?

Once fully dried, air dry clay cannot be reconstituted. However, if your clay starts to dry out while working, you may be able to revive it by kneading in a small amount of water. Work quickly before the clay fully dries.

Is air dry clay waterproof?

Air dry clay is porous when dry, so water can cause damage over time. Seal finished sculptures with acrylic sealer, polyurethane, or varnish for water resistance and durability.

Can you bake air dry clay?

No, air dry clay should never be baked as high heat can cause melting, burning, or damage. Let air dry clay fully dry at room temperature only.