How to Sculpt With Concrete

Casting the Concrete

Select a cast. Before you mix your concrete, you must first secure a cast. A cast can be homemade cast made from plastic or styrofoam or purchased at a hardware store. You can also find a wide array of concrete casts to purchase online.

Combine the concrete mix and water. Empty a bag of concrete mix into a large bucket or wheelbarrow. Carefully measure out the recommended amount of water. For example, an 80 pound (36 kg) bag of concrete typically requires about three quarts (2.8 liters) of water. Add approximately two-thirds of the water to the concrete mixture. Set aside two cups (0.5 liters) of concrete mix. This mix can be added to the concrete if the consistency is too runny. Read the mixing instructions on the bag of concrete to ensure that you have the correct ratio of water to concrete mix.

Mix the concrete. Use a concrete mixing tool, hoe, or drill bit to mix the concrete together. Continue to add the water that you have set aside until you reach a thick, oatmeal-like consistency. The wet concrete should hold its form if you squeeze a fistful. Concrete that is too runny is easier to pour but less durable and more likely to break over time. Add more water to your concrete mixture if the mixture is solid and crumbly.

Pour the concrete into the cast. Slowly pour the concrete mix into the cast until it is completely full. Use a metal trowel to smooth the top of the concrete. You can apply a small amount of engine oil to the cast before pouring the concrete to ensure that the concrete is removed from the cast easily without damaging the sculpture.

Remove the cast. Once the concrete is completely dry, remove the cast. Most casts are removed after one day. Sometimes, the sculpture is removed from the cast and the cast remains intact. Sometimes, the cast is cut away to reveal the sculpture. Allow the cement to cure for at least one week before use. Read the instructions that come with the cast. These instructions will give you specific information about when and how to remove the cast. Each project will be different.

Carving Concrete

Locate carving tools. Carving tools, such as knives, scrapers, and hammers, that are typically used for ceramic sculpting work best to carve concrete. You can find these tools at most craft or art shops.

Lay out your design. Freehand or stencil your desired design onto the concrete with a pencil or chalk. This will give you a guide to work off of.

Mix and pour the concrete. Using the directions on the bag of concrete, mix the concrete in a large bucket or wheelbarrow. Most 80 pound (36 kg) bags of concrete require three quarts (2.8 liters) of water. Pour the concrete into the desired concrete mold and allow it to partially dry before beginning the carving. Pour the concrete in small, workable sections to prevent the concrete from drying before you finish the sculpting. Concrete that is too runny is easier to pour but less durable and more likely to break over time. Add more water to your concrete mixture if the mixture is solid and crumbly. The amount of time that you need to wait will depend on the thickness of the concrete mold. The concrete is ready to carve when it is still malleable and holds it’s shape.

Carve the design. Before the concrete is completely dry, begin to carve out your design using the sculpting tools. Begin at the top of the sculpture and work your way down. You will have to work quickly in order to finish the carving before the concrete dries. Try to finish a section of concrete within one hour of pouring. Coat your hands in petroleum jelly to prevent the concrete from damaging your skin. Avoid touching the surface of the sculpture until it is completely dry to prevent any smudging. The concrete should be dry within 24 hours but should be left to cure for seven days.

Using Mesh

Cut the mesh. Cut the metal mesh into the desired shape using wire cutters. This mesh will serve as the framework for your sculpture. It will hold the wet concrete in place until it dries. Use a metal mesh that is heavy enough to hold its own shape.

Wrap the mesh around something hard. If you are unable to manipulate the mesh into your desired shape, try wrapping the mesh around something hard, like cardboard or styrofoam, to form the desired shape of the sculpture.

Mix the concrete. Mix the concrete mix and water in a large bucket or wheelbarrow. Use a concrete stirrer, hoe, or drill bit to stir the concrete until it is thoroughly mixed. Most 80 pound (36 kg) bags of concrete require three quarts (2.8 liters) of water. The mixture should be a thick, oatmeal-like consistency. Read the instructions on the bag of concrete before mixing the concrete and water. The instructions will provide clear ratios of water to concrete. Concrete that is too runny is easier to pour but less durable and more likely to break over time. Add more water to your concrete mixture if the mixture is solid and crumbly.

Apply the concrete to the mesh. Using a metal trowel, or another hand tool, apply the concrete to the wire mesh. Apply the concrete in thin layers. Add more layers until you achieve your desired shape.

Let the concrete dry. The concrete will be dry to the touch within 24 hours. However, you should allow the concrete to cure for seven days. Avoid touching or moving the sculpture during this time.