How To Make Plaster of Paris Molds

The name ‘Plaster of Paris’ is derived from the term “gypsum” which is a mineral found in a district in Paris named Montmartre. It is a powdered substance, which only needs water for its mixture. You just need a few minutes to let it harden and you’re all set to use it for molding. It is commonly used in making furniture, figurines and even mannequins.

In the past, people created pots and figurines from mud clays and wood. With plaster molds, you can create a perfect replica of an item with less time and effort. This material can be used over and over again. Just fill the mold with this material, bake it, and you’re done!

In order to create more replicas, here are a few guidelines on how to make plaster of Paris molds.

  • Prepare the materials to be used. You need to prepare a small bottle about 4” tall, modeling clay, a wooden box larger than the object to be used or about 6” x 6”, plaster of Paris, sand paper, and separating agent (ex. Petroleum jelly or Vaseline).
  • Make the mold. Prepare the object to be molded. Cover the bottle with any thin piece of paper or cardboard of the same size. This is done to prevent the plaster from pouring into the bottle. Add a little of the separating agent all over the bottle for easy removal. Lay it inside the wooden box on top of the clay. Using your clay, cover up the side of the bottle until it is half buried. Since you are making two molds, you need to smoothen out the clay surface thoroughly. Mix the plaster of Paris with water and stir until it becomes a thick liquid substance. For best results, refer to the instructions on the label. You can now pour in the plaster in the wooden box immediately after mixing it. For about 15-20 minutes, the mixture will harden. To know if the mixture is ready, you can gently touch the surface of the mold. Turn the wooden box upside down and gently remove the clay. Now what you need to do is remove the bottle from the hardened plaster. You need to do it really slowly and surely so you won’t have to re-do the whole process. Use a sand paper to smoothen out the surface of the two molds. You can also lay the molds side by side on a flat surface to see whether they are of the same size and shape.
  • Tips. One tip to share is to do a trial run before making the actual mold. Get a piece of clay larger than that of the printed shape and press it thoroughly. Join both molds together. Put an extra amount of clay (or as needed) to ensure that you get the right shape. Press both molds down on each other. Make sure that the replica must look exactly the same as that of the original piece. Cut or scrape the excess clay as necessary.

Quite easy isn’t it?  Remember to practice making the mold first before making the actual one, and you’ll eventually get the hang of it.


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