How to Make a Sphere Mold

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Things You'll Need

  • Silicone Plastique Part A

  • Silicone Plastique Part B

  • Mold release

  • Sphere model

  • 4 wooden craft balls

  • Rubber band

  • X-acto knife

A sphere you can create in a mold.

Molds, which are template forms for casting multiple identical copies of the mold design, can be created in many different ways. Some popular methods of mold making are creating one-part molds, two-part molds and three part molds. Most molds are made from a liquid material, which must be poured into a mold box or painted onto the model you would like to copy, but you can also shape a flexible solid material directly on your model. To use this type of mold on a sphere, you will be making a two-part mold.

Step 1

Open your containers of Silicone Plastique Parts A and B. Mix each part together in equal amounts, kneading the material like clay. Continue mixing until the colors blend into each other evenly.

Step 2

Coat your sphere model with mold release, so that the silicone material does not stick permanently to the model.

Step 3

Apply the material to the bottom half of the sphere model, forming it around the bottom of the sphere. You can cover the model with a thin layer of silicone, so that the outside of the mold is spherical, or you can make a thicker, sturdier mold by packing on more silicone, so that the outside of the mold is square. A square mold will be able to stand up on its own.

Step 4

Push any of the excess material up to the middle of the sphere and form a "ledge" there that sticks out away from the sphere, if you have not made a square-shaped mold. Press wooden craft balls into the top of the ledge, so that you will create keying impressions in your mold.

Step 5

Strap the mold half to the model sphere, using a rubber band. Let the mold sit for one hour to cure.

Step 6

Remove the rubber band and wooden craft balls. Coat the top of the mold half with mold release.

Step 7

Make another mixture of Silicone Plastique. Form the mixture over the top of the sphere model, matching the bottom half. Let the mold sit for one hour.

Step 8

Pull the mold halves apart and remove the sphere model. Place the mold halves back together, matching the keying impressions. Wrap a rubber band around the mold to hold it together.

Step 9

Take an X-acto knife or craft knife and cut a small hole in the top of the mold, through which you can pour your casting material.

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