How to Make a Mold for Cast Metal

By Kayla Lowe

Molds are helpful when casting duplicate forms of metal. They greatly reduce the amount of work required to cast metal and are ideal for creating numerous identical sculptures, figurines and pieces of jewelry. The process of making a mold can be difficult and time consuming. However, the mold will prove invaluable to the duplication process later on.

Roll the clay on the pallet board thick enough to press half of your metal figure, statue or other model into.

Press the metal model halfway into the clay so that half of the model is pressed within the clay and the other half is sticking up out of the clay. A mold for the other half of the model will be constructed later.

Use clay working tools to level off the clay around the model.

Create a funnel to pour metal into the mold. The funnel should lead directly to the model, as this is how the metal will be poured in the mold.

Cut the clay in straight lines approximately ¾ inch away from the model. Make sure you cut directly against the top of the funnel, as it must be on the edge of the mold so you can pour the metal.

Construct a foam board wall around the clay that is ½ inch higher than the highest point of your model. Hot glue the bottom of the wall to the pallet board.

Place a piece of plastic wrap over the top of the model, and pour water on top of the plastic wrap with a measuring cup. Take note how much water it takes to fill the model to the top of the foam board for this will let you know how much rubber to mix.

Remove the water and plastic wrap from the model, and coat the model and the clay with a release agent. This will keep the rubber from sticking to the model or the clay.

Mix and pour the rubber into the first half of your mold, filling it to the top of the foam board.

Mix and pour the rubber into the first half of your mold, filling it to the top of the foam board.

Allow the rubber to cure by allowing it to sit undisturbed for approximately 24 hours.

Remove the foam board wall and the clay from the rubber to reveal the first half your mold.

Repeat the above steps to create the second half of your mold using the opposite side of your model.

Things Needed

  • Clay
  • Pallet board
  • Metal model
  • Clay working tools
  • Foam board
  • Hot glue gun
  • Plastic wrap
  • Measuring cup
  • Release agent
  • Mold making rubber

Tip

Purchase a release agent and mold making rubber at hardware stores or online.

Warning

Pour the rubber into the molds slowly and let it slowly rise to prevent air bubbles from getting trapped in the rubber and deforming your mold.

References

About the Author

Kayla Lowe has been a freelance writer since 2008. She writes for various online publications and is also the author of the book "Maiden's Blush," a Christian-fiction romance novel. Lowe is pursuing a degree in elementary education.