How to Use Air-Dry Clay in Molds
I love to use air-dry clay in molds to create jewelry pieces and beautiful accents and embellishments for my mixed media projects. Using a mold with the air-dry clay removes some of the stress when trying to sculpt that perfect flower or bird with clay carving tools. The tools are wonderful to add details and dimension to the air-dry clay. But you can create many clay pieces at the same time using silicone molds.
You need a few tools when you use air-dry clay in molds. Most of the tools you probably already have in your craft area.
- Silicone gloves – This keeps the air-dry clay from sticking to your hands while you condition it and put it in the molds.
- Water – You smooth the edges of your creations with a bit of water on your hands to give the air-dry clay a flat back while it is in the mold.
- Palette knife or flat edge – Scrape a palette knife or flat edge ruler across the clay while it is in the mold to remove excess clay from the edges of the clay piece.
- Talcum Powder – Dust the molds with a brush dipped in talcum powder to help the air-dry clay release from the mold.
- PVA Glue (wood glue) – Provides a permanent bond when gluing air-dry clay pieces together or to other surfaces.
- Acrylic paint (optional) – Use as a colorant to add color to your air-dry clay pieces either before molding or after the clay is dry.
Silicone versus Plastic
I prefer to use air-dry clay in silicone molds because they are flexible enough that the molded clay releases easily. The plastic molds are more rigid, and I often must leave the air-dry clay in the plastic mold until the clay is almost completely dry before I can remove it. Often by that time, the air-dry clay is too hard for me to shape it around a curved surface.
Size and Thickness Matter
When you use air-dry clay in molds, consider how thick the molded piece is going to be. A good thickness for air-dry clay is about ¼ inch. The clay dries uniformly and is less prone to cracking, in my experience. Also, the thinner pieces seem to release better with less damage to the details. You can see in this picture that the Eeyore was damaged because he was too thick to release smoothly.
Remember that the thicker your air-dry clay, the longer it will take to dry. You must also continuously flip the clay piece so that it dries evenly. I find with a ¼ inch thickness, I only need to flip it once during the drying time.
Treat the Mold
You must start with clean molds when you work with air-dry clay. Wash the molds in warm soapy water. Allow them to dry completely before using the air-dry clay in the molds. Moisture in the molds will result in air bubbles forming in the clay surface. The surface will not be smooth and could ruin your finished piece.
If the mold you use for the air-dry clay is ornate or complex, use a soft brush to dust the mold with corn starch or talcum powder. The surface of the air-dry clay will absorb the powder and create a minute barrier so the piece releases easily from the mold.
Conditioning the Air-Dry Clay
This is a particularly important step when you use air-dry clay in molds. Your clay must be pliable, so it gets into all the creases and crevices of the mold to create the perfect finished piece. Simply knead the piece of air-dry clay in your gloved hands until it is soft and pliable. Depending on the brand of air-dry clay you use, this can take a few minutes. But it is well worth the effort if you want your finished pieces to pick up all the details in the mold.
Adding the Air-Dry Clay
Look at the basic shape of the mold you are using. Is it circular, square, long and thin, or curved? Make the piece of air-dry clay you want to use in the mold close to the same shape. For small leaves or jewelry pieces, I roll a small piece of the air-dry clay into a ball and place the ball into the middle of the mold. I then press in the middle and work the air-dry clay outwards to the edges of the mold.
For a long, thin piece, I will create a coil the length of the mold. I place the coil from one end to the other of the air-dry clay mold. Starting at one end, I push the clay into the crevices of the mold until I know that the entire surface of the air-dry clay is in total contact with the mold.
Once I have the air-dry clay in the mold, I use the edge of a palette knife to remove the excess clay. The motion I use is similar to skimming the edge of a knife across the top of a cake to make the frosting smooth. I do this in one smooth motion for small pieces. I do the larger pieces one part at a time. I want the excess clay removed from the edges and I want a flat back for my pieces. This results in less time sanding or cleaning up when the air-dry clay pieces are removed from the molds. This is especially important if you have to let the clay dry in the mold before removing the piece.
Use your finger or sponge dipped in a bit of water to smooth the exposed surface of the air-dry clay once it is in the mold. This will give you a smooth, flat surface on the back of your piece once it is dry.
Removing the Clay Pieces
The easiest way to remove air-dry clay from molds is what I call the rolling method. Allow the air-dry clay to sit in the mold for a few minutes so it has time to firm up slightly. Flip the mold over so the clay is laying on your work surface. Slowly bend back a section of the mold and watch for the clay piece to start lifting from the mold. With your other hand, gently (very gently) help release the air-dry clay from the mold. Turn the clay piece over so it lays flat on the work surface, and allow it to dry completely. Remember to flip the piece if it is thick.
Air-dry clay shrinks as it dries. If your piece does not readily release from the mold, let it dry in the mold, so you reduce the risk of damaging the piece. This step neither damages the air-dry clay or the mold.
Inserts and Holes
You may want to add an eyelet or hole into your air-dry clay piece. In the mold, you cannot do this. Instead, release the air-dry clay from the mold while it is moist. Lay the piece on a flat surface and create a hole where you want with the open end of a straw. To add an eyelet, slowly insert it into the top of your air-dry clay piece. A quick thrust into the clay could damage the shape of your piece so take your time. If your eyelet is the screw type, screw it in as you would in other applications.
You can make a hanger for your air-dry clay piece with a small section of thin wire. Make a loop of wire and embed it into the back of the air-dry clay piece when you put it in the mold. When the piece is dry, the wire becomes part of the clay. I will say that this is not my preferred method. I find that after some time, the section where the wire is embedded can deteriorate and break off. I prefer using an eyelet if I want my air-dry clay pieces to hang.
When I use air-dry clay in molds, I find that dry times vary by the type of clay and the type of mold I use. Small, thin pieces dry faster than pieces that are thicker, of course. I also noticed that more moisture in the air-dry clay causes the clay to dry much slower. However, if I condition the air-dry clay properly before putting it in the molds, it cuts down on the drying time. I assume this is because I have evenly distributed the water in the clay and reduced some of the moisture while during conditioning.
You can see that the ones on the left were damaged when I removed them from the molds because there was too much moisture still in the clay when I removed them. The ones on the right were thin enough and I conditioned the clay longer.
Colors and Coatings
You can buy air-dry clay in a variety of colors. I prefer to use the natural air-dry clay in the molds and paint or guild my pieces once they are dry. If you want to color your clay, you can use powdered pigments or water-based paints. If you use paint, remember to add just a little at a time and work the paint into the clay thoroughly. Any added moisture in air-dry clay can give varying results in the finished piece.
And one final thing you must know when you use air-dry clay in molds is how to seal your piece. You can use a clear spray varnish to seal the entire piece, so it is water-resistant. You may prefer to use a brush to apply a sealant. I prefer the spray because it seems to dry faster. But that is my personal preference. You may want to do something completely different. Some artists dip their finished air-dry clay pieces in a polyurethane coating. The choice is yours. As long as you create, that is all that counts!