Concrete Plant Pot Casting Mold

This project is a 3D-printable mold system designed to create silicone molds, which can then be used to cast decorative concrete plant pots.

After printing all parts, you can choose one of the available 3D-printed plant pot designs (more variations may follow in the future) and integrate it into the mold setup.

These small plant pots make great gifts for friends and family, especially when paired with little plants.

Have fun creating!

Assembly

1. Start by mounting your selected plant pot onto the baseplate.
   I used an M4 screw and nut to securely fix it in place.
2. Next, place the outer shell (“mold”) around the baseplate.
   Fasten it using two additional M4 screws and nuts.
3. Then attach the “bridge” with the “negative-pothole” element.
   For this step, I used a standard 4 mm wood screw.

Casting the Silicone Mold

• Make sure to place the setup on a protective surface, as some silicone may leak during the relatively long curing time. Once cured, any excess silicone can easily be peeled off.
• Be careful while pouring to avoid silicone flowing into the negative-pothole section.

After the silicone has fully cured, disassemble the mold in the following order for easiest removal:

1. Remove the outer shell (“mold”)
2. Remove the baseplate
3. Finally, remove the negative-pothole component

Casting the Concrete Pot

You can now use the silicone mold to cast your plant pot.

• Before pouring the concrete, lightly coat the inside of the silicone mold with a bit of vegetable oil. This helps with demolding later.
• I used craft concrete for this step.
• Fill the mold up to the top edge and smooth the surface to ensure the base of the pot is even and stable.

Waterproofing the Pot

Since cast concrete is not waterproof, the finished pot should be sealed:

• You can use a sealing product such as plaster sealant, or
• Alternatively, I personally use the 3D-printed insert (“plant-pot-inside”) to prevent water from soaking through the concrete.

Materials I used

• Silicone
• Concrete
• Sealant