In this article, we will show you how to make a simple silicone mold, a plaster tub, and then cast a plaster or concrete sculpture. The production of silicone molds varies greatly according to the project, for this case of a simple bust shape, the so-called multilayer stripping silicone mold will suffice.

3D tisk

First, we will print a model of the sculpture using 3D printing . You can find many models, for example, on the Myminifactory website, for example, we chose a scan of an existing statue of an unknown Greek philosopher.

The bust is printed on a larger printer and reaches a height of about 40 cm.

3D tisk busty

3D tisk busty

Silicone form

Then we paint the bust with silicone (we used Rebound 25). Apply another layer in 24 hours. We put a total of 4 layers for a sufficiently thick mold wall.

Silicone form

Silicone form

Gypsum hull

Now we will make a plaster tub (a two-piece is enough for a simple shape). We will make a dividing line according to the shape of the statue in two halves. First, make one half by applying soaked gypsum bandages (or gypsum + glass fibers for greater strength) and make one half of the mold shell.

After drying, apply the other half of the hull. Always remember before each work to add some separation medium (it can be oil or a special spray release) for easier separation of molds.

Gypsum hull

Gypsum hull

As soon as the hull dries, we separate it from the silicone mold and then remove the 3D printed model from the silicone. The silicone is very flexible and pliable, so with a simple shape we can roll it up from the model. For more complex shapes, cut silicone and remove the model.

Concrete casting

Once we have the necessary equipment ready, we will put the empty mold back together and pull it off using cable ties, rope or wire. We spray the mold with a separating jig and fix the mold in a horizontal position.

Now we can prepare the concrete mix and cast the casting . You can use a mixing device to mix the concrete. You can knock out the resulting bubbles or use a vacuum pump and a vacuum vessel.

In our case, unfortunately, the mold is larger than our vacuum vessel, so we try to get the bubbles away by tapping the mold.

Concrete bust

Concrete bust

We can mix concrete with various materials , colors and create, for example, an imitation of marble.

Once the concrete is stiff enough (at least 24 hours), remove the hull and remove the silicone mold. The concrete gains full strength only after a few days and reaches its maximum stiffness only after a month, at the same time it is necessary to sprinkle the concrete with water for some time, which the concrete absorbs into itself.

After sufficient hardening, we can still repair minor defects and grind the concrete, or repair the bubbles.

Then we use penetration and various stone varnishes to achieve a shiny stone appearance.

The result is a nice stone statue that will stand out nicely both in the study and in the garden as a decoration. You can use the mold repeatedly and try different materials and colors.

Are you interested in making a mold, but don't have the time or desire to make a mold yourself? We will be happy to help you. Order the production of a silicone mold or our entire casting to order from us.

Alternatively, for those interested, we also offer an individual course in creating a silicone mold.

Just write to us at info@futlab.cc