Can You Make Air Dry Clay Dry Faster?
Air dry clay, as the name suggests, is clay that dries or cures with air. It typically has a spongy, soft, and light composition which makes it easy to mold and shape. Air dry clay is popular for crafting and modeling because it does not require baking or firing in a kiln like traditional clays. However, one downside is that air dry clay takes longer to fully cure and harden compared to clays that require heat.[1]
Many crafters and artists want their air dry clay projects to dry faster so they can complete them more quickly. Air dry clay that dries faster allows pieces to be handled, worked on, painted, sealed, or displayed sooner. Speeding up the drying process also reduces the risk of pieces becoming dented, damaged, or deformed while the clay is still soft. Therefore, understanding techniques to accelerate the drying time of air dry clay is beneficial for efficiency and achieving desired results.
Temperature
Higher temperatures cause air dry clay to dry faster. When exposed to increased heat, the water molecules in the clay gain more energy and evaporate at a quicker rate 1. The ideal temperature range for fast drying air dry clay is between 200-250°F. According to Sculpey, baking air dry clay at 200°F significantly decreases drying time compared to room temperature 2. While higher temperatures speed up drying, too much heat can cause cracking or burning. Staying within 200-250°F allows the clay to dry fast without damage.
Air Circulation
Moving air speeds up the drying time of air dry clay. Using a fan or hairdryer on a low setting can help circulate air around the clay to remove excess moisture. However, avoid blowing air directly onto the clay as this can cause uneven drying and cracking (Source). The key is to gently move the air without over-drying any one section too quickly. Position a fan several feet away and have it circulate the air in the room. Or use a hairdryer on the lowest and coolest setting while moving it around the clay (Source). This will accelerate the overall drying time without putting too much concentrated heat or air on the clay itself.
Surface Area
Clay dries from the outside in, so increasing the surface area exposed to air will speed up drying time. Sculpting thin sheets or flattening the clay into pancake shapes maximizes surface area and allows moisture to evaporate more efficiently. According to Drying Shrinkage, clays shrink as inter-particle water evaporates during drying. For a quicker overall drying time, optimize the surface area to volume ratio by sculpting many thin protrusions rather than one bulky mass.
Clay Thickness
Thinner pieces of air dry clay dry faster than thicker pieces. This is because the water in the clay has less distance to travel from the interior to the surface as the clay dries out. According to the article “How To Dry Pottery Clay: Process, Tips and Techniques”, if your pottery is half an inch thick or greater, then it is recommended to leave it to dry for up to three weeks. However, thinner pieces like small ornaments or tiles that are 1/4 inch thick or less may only take 1-3 days to fully dry.
The thickness of the clay affects drying time because water can escape through the surface of the clay as it dries. The more interior clay that the water has to travel through to reach the surface, the longer it will take. Thinner pieces have less distance for the water to travel. Additionally, thicker pieces retain more water overall, meaning there is simply more water that needs to fully evaporate. So for fast drying, aim for thinner clay pieces, while being cautious of pieces drying too fast and cracking if they are very thin.
Clay Composition
Some clays naturally dry faster than others. Air-dry clays contain various ingredients and formulations that impact their drying time. For example, clays with higher amounts of cellulose ether tend to dry more quickly as the cellulose ether accelerates water absorption. Clays made with Celluclay or methylcellulose generally dry faster than clays containing polyvinyl acetate or PVA. Craftsmart Air-Dry Clay and ACTIVA Air-Dry Clay are examples of fast-drying cellulose ether-based clays. Clays with lower amounts of oil-based ingredients also tend to dry faster. Professional clays like Amaco Stonex Clay and Van Aken Plastalina Modeling Clay dry quickly thanks to their specialized formulas with minimal oils. Checking the clay ingredients can help determine which will dry the fastest.
According to finance.yahoo.com, “The Best Air-Dry Clays for Fast and Easy Crafting,” cellulose-based clays like DAS Air-Hardening Modeling Clay and Craftsmart Air-Dry Clay dry the fastest. Clays with higher oil content tend to take longer to fully cure.
Baking
Baking air dry clay in the oven for a short time before air drying can help speed up the drying process. According to this source, baking clay first helps remove moisture quickly so the remaining drying happens faster. Baking time depends on the size and thickness of the sculpture – small pieces may only need 10-15 minutes at low heat like 275°F. Be sure not to overbake or the clay can become brittle and prone to cracking when air drying after. Technically air dry clay can be baked according to this source, but take care not to exceed 275°F and closely monitor during baking to prevent cracking or damage.
Sealants
Sealants, such as varnish, acrylic sealer, or waterproof sealant, are commonly used on air dry clay projects to protect the surface and make it more durable. However, sealants can actually slow down the drying process of air dry clay significantly. This is because sealants create a protective barrier on the surface that blocks moisture from evaporating out of the clay.
According to Gathered, adding a sealant to air dry clay “is a particularly good idea if paint or any other colour has been added to the surface.” But they caution that sealants will extend the drying time.
Similarly, Gathering Beauty notes that sealants make the clay water-resistant but warns they do not allow moisture to evaporate quickly from the clay.
Therefore, if you are looking for ways to speed up the drying process of air dry clay, it’s best to avoid using any type of sealant. Allowing the clay to dry fully before adding a protective finish will result in the fastest drying time.
Humidity
Lower humidity speeds up the drying process for air dry clay. This is because moisture evaporates more quickly from the clay in dry air compared to humid air. According to a study published in the Journal of Materials Processing Technology, drying clay at lower relative humidity levels results in faster moisture loss and drying times (source).
To speed up drying, it helps to use air dry clay in a dehumidified environment. Using a dehumidifier or placing the clay in a naturally drier spot like an air conditioned room will significantly decrease drying time. Reddit users on r/polymerclay report much faster drying times when using a dehumidifier or drying clay in lower humidity environments (source). Maintaining relative humidity around 30-40% is optimal for fast clay drying.
Conclusion
There are several methods you can use to speed up the drying time of air dry clay. The most effective strategies involve exposing the clay to warmer temperatures, better air circulation, and dividing projects into thinner sections.
Increasing the temperature around the clay is one of the simplest and most effective ways to decrease drying time. Try placing clay projects near a heat source like a radiator or in a sunny window. You can also use a hair dryer on a low setting to gently warm the clay’s surface.
Improving air flow is another key tactic. Set up a fan nearby to keep air moving over the clay’s surface. Rotate pieces periodically so all sides are exposed to the airflow. Avoid enclosing clay in tight spaces that block ventilation.
Finally, minimizing the thickness of clay sections is important. Sculpt thinner layers that are 1/4” or less, and avoid large solid pieces. This gives moisture more exposed surface area to evaporate from. Letting clay fully dry between adding layers helps too.
With the right techniques, air dry clay can dry in under 24 hours. Monitor the clay closely and adjust temperature, airflow, and thickness as needed for optimal results.