Why Is Air Dry Clay Bad?

Air dry clay, also known as claycraft or no-bake clay, is an arts and crafts medium made of a malleable material that hardens and holds its shape when air dried at room temperature. Unlike ceramic clay that needs to be fired in a kiln, air dry clay can be hardened without an oven or heat source.

Air dry clay has some advantages, like being kid-friendly and not requiring additional tools or equipment to harden. However, it also has some downsides compared to ceramic modeling clay that limit its applications and durability. This article will examine the main reasons why air dry clay may be considered “bad” for certain clay projects and art mediums.

Lower Quality Finish

One of the biggest drawbacks of air dry clay is that it produces a lower quality, more brittle finish compared to ceramic clays that are fired in a kiln. When air dry clay dries, it hardens but still retains a significant amount of water content. This results in a finish that is prone to cracking and creates an uneven, porous surface. Pieces made from air dry clay lack the smooth, durable finish that can be achieved with kiln-fired clays. The firing process vitrifies the clay, sealing the surface and creating a glass-like hardness. Air dry clays do not undergo this process, so they retain a more chalky, brittle texture. Even when sealed with varnish or paint, air dry clay projects have a noticeable fragility and porousness. The unrefined finish also shows fingerprints, smudges, and imperfections much more than fired ceramic clays. For miniaturists, crafters, and hobbyists requiring a high quality, durable finish, air dry clays fall short.

Limited Durability

One of the main drawbacks of air dry clay is its limited durability compared to polymer clay, earthen clays, or pottery clay. Pieces made from air dry clay tend to be more fragile and delicate. They don’t hold up as well to regular handling or long-term display. Air dry clay is prone to chipping, cracking, or crumbling more easily, especially around thinner parts or finer details. The lightweight, porous material can break down faster just from exposure to air over time. Pieces may start to deteriorate within weeks or months rather than lasting for years. This can be frustrating if you put a lot of time and effort into a detailed sculpture or model. Air dry clay’s durability issues make it a poor choice for toys, decorative items meant to last, or keepsakes. While air dry clay works well for short-term crafts or temporary projects, the finished pieces lack longevity compared to clays that can be fired in a kiln. For more permanent sculptures, durable finishes, or professional-quality models, air dry clay may simply not withstand the test of time.

Can’t be Fired

One of the biggest downsides of air dry clay is that it can’t be fired in a kiln like ceramic clay can. Firing is the process of baking clay at extremely high temperatures in order to harden, strengthen, and waterproof it. When ceramic clay is fired, the clay particles fuse together through vitrification and become a solid piece of pottery or sculpture.

Air dry clay, on the other hand, simply dries and hardens at room temperature. The clay particles remain separate rather than fusing together when dried. Because air dry clay never goes through the firing process, it remains porous and fragile. Any pieces made with air dry clay won’t be able to withstand much use or frequent handling. Air dry clay is best for decorative objects rather than functional pottery or ceramic dinnerware.

Prone to Breakage

One of the biggest drawbacks of air dry clay is that it is prone to chipping, cracking, and breaking apart. Even when handled with care, air dry clay pieces can easily break or crack when they are being sculpted, shaped, transported, or displayed. This is because air dry clay contains no binders or firing agents to strengthen it like polymer or ceramic clays do. The drying process that cures air dry clay is fragile and can leave air pockets or structural weaknesses in the clay that lead to breakage. Pieces made from air dry clay need to be handled very gingerly to avoid cracks or chips, especially at thinner areas and joints. Even tapping or bumping an air dry clay sculpture can cause parts of it to break or fall off. Air dry clay pieces are also vulnerable to cracking or crumbling if they are dropped. All of these factors make air dry clay an impractical choice for sculptures or projects that require durability or frequent handling. The fragile nature of air dry clay limits its usefulness for anything other than decorative objects that will be gently handled and displayed.

Difficult to Seal

Air dry clay is very porous and permeable to moisture. This makes it challenging to properly seal and protect air dry clay creations. Without an effective sealant, air dry clay will absorb moisture from the air and begin to break down over time. Pieces made from air dry clay are prone to showing signs of wear much faster than polymer clay or ceramic pieces.

Applying varnish, polyurethane, or other sealants can help protect air dry clay creations. However, many sealants do not adequately penetrate and seal the porous clay. This leaves the interior matrix still vulnerable to moisture damage. Finding the right sealant and properly prepping and sealing the clay is crucial, but not always successful.

Unsealed air dry clay is best suited for short-term decorative or non-functional pieces. Any creations meant to last or withstand use will require extensive sealing to try and protect the clay over time. Even with the best efforts, it can be difficult to fully seal air dry clay in a way that prevents long-term moisture damage.

Limited Size

One of the drawbacks of air dry clay is its limited size for pieces and structures. Unlike ceramic clays that can be used to create large sculptures, air dry clay has restrictions on how big it can be formed and still dry and harden effectively.

Air dry clay pieces are generally limited to smaller crafts, miniature items, jewelry, figurines, etc. Trying to create anything too large with it can lead to cracking or collapse as the interior clay remains wet and fails to properly cure. Pieces over a couple inches thick tend to develop drying issues.

This size limitation occurs because air dry clay relies on evaporation to harden. The greater the volume and thickness of clay, the more moisture has to come out for it to fully cure. But moisture can’t easily escape from the innermost clay in a large mass.

Using an air dry clay armature for sculpture is unwise for similar reasons – the structural integrity will be lacking for supporting a heavy outer layer of clay that would be needed for a full-size sculpture. Air dry clay simply dries too soft and shrinks too much as it dries to be effective for large-scale works.

So crafters and artists have to stay relatively small in scale when working on air dry clay pieces. For anything bigger, a more durable oven-fired clay is a better choice to allow for ample strength and internal drying.

Fewer Creative Options

Air dry clay offers fewer creative possibilities compared to ceramic clays that can be fired in a kiln. With ceramic clays, artists can create sturdier sculptures in bolder shapes and larger sizes. The firing process allows the clay to be shaped while wet, then hardened into a permanent finish. This enables more intricate detailing, flowing curves, and thin extensions that would not be possible with fragile air dry clay.

In contrast, air dry clay is limited to items that can be formed and fully supported while the clay is drying. Intricate shapes risk slumping or sagging as the moisture evaporates. Items must also be small enough to dry thoroughly without cracking. The finished pieces remain relatively soft and brittle after drying. This restricts the creativity of what can be built, decorated, and used. While air dry clay works for simple hobby projects, ceramic clays offer far more versatility for truly artistic, durable clay creations.

Can’t be Reused

One of the biggest downsides of air dry clay is that once it has dried out, it cannot be reconstituted or reused. Unlike polymer clay which can be conditioned and reused indefinitely, air dry clay is made of materials like cellulose or calcium carbonate that lose their plasticity once all the water evaporates.

Even if you try to rehydrate dried out air dry clay, it will never go back to its original smooth and malleable state. At best, it may turn into a crumbly or mushy mess that is not suitable for sculpting or modeling. Any hardened pieces that have fully cured cannot be salvaged at all.

This means that any unused clay that is left out to dry is wasted, and you can’t remix old unused pieces back into a reusable lump. It also means that if a sculpture made from air dry clay breaks or cracks after drying, it is very difficult if not impossible to fix it by adding more clay. The irreversible drying process makes air dry clay inherently non-reusable.

Conclusion

In summary, air dry clay has several key disadvantages that limit its usefulness for many clay modeling projects. Its lower quality finish and durability issues make it unsuitable for pieces meant to last more than a few years. The inability to fire air dry clay means it can never achieve the hardness and permanence of real fired clay. Air dry clay’s tendency to breakage and difficulty sealing it also hamper the creative process. The small size of commercially available air dry clay packs restricts the size of projects. And because air dry clay can’t be reused, artists have fewer options to rework their pieces. For all these reasons, air dry clay lacks the creative flexibility and archival stability of genuine clay fired in a kiln. Artists requiring professional-grade results for their modeling and ceramic art are better served by working in real clay.