Copy a Figurine using a Rubber Mould
Mould-making is the most common way to translate a model design into another material, and lets you make multiple identical copies of the model. One type of mould used to copy figurines is the rubber mould, which is a flexible mould that does not ruin the original object. The best method for making a rubber mould of a figurine is the two-part process, which creates a mould that separates evenly down the middle.
You Will Need:
Legos or cardboard
1 quart silicone RTV rubber
Wooden craft balls
Make the First Rubber Mould Impression
1 Create a mould-making box with an open top and bottom that is large enough to enclose your figurine. You can make the box out of Legos if the figurine is small, or out of pieces of cardboard taped together. Make sure that the box is at least 1/4 inch larger than the figurine in all dimensions.
2 Flatten a piece of modeling clay on a work surface, so that you have a half-inch-thick rectangle that is slightly larger than the bottom opening of your box. Place the box onto the modeling clay, creating a bottom. The box does not need to be rectangular or square, but it must be larger than your figurine in all dimensions.
3 Mix together no more than half of your silicone rubber with its catalyst, using a plastic cup and a stirring tool, such as a wooden dowel or Popsicle stick. Make sure that there are no air bubbles in the mixture.
4 Pour the mixture into the box until it is half filled.
5 Press the figurine into the rubber, making sure that it is half covered. Do the same to several wooden craft balls or marbles, making impressions around the figurine; These impressions will help you fit the mould together later.
6 Let the mould sit for at least 12 hours so that the rubber hardens.
Finish the Rubber Mould
1 Remove the craft impression balls from the first half of the mould. Mix the rest of the silicone rubber and catalyst.
2 Pour the silicone rubber mixture into the box, over the figurine, until the box is filled and the figurine is completely covered.
3 Let the mould harden for 12 hours. Remove the mould halves from the box and pull them apart gently, then take out the figurine. The mold should separate with little trouble, as silicone rubber does not easily stick to itself.
4 Put the mould together, making sure that the edges and impressions line up on each half. Bind the mould halves with rubber bands.
5 Carve a small hole in the bottom of the mould, using a razor blade. Make sure to carve the hole deep enough to reach the figurine impression cavity on the inside.
To determine exactly how much rubber you will need, you should know the liquid capacity of your moulding box. One quart of rubber should be sufficient for a small figurine;If you are working on a large figurine, the rubber also comes in half- and full-gallon jugs.
You can purchase silicone RTV mouldmaking rubber online through most art stores, as well as moulding and casting suppliers.
When the mould is finished, you can pour your casting material directly into the hole you carved. Take the mould apart again once the casting material has dried.
This method will work only for figurines that do not have holes or openings in them. If you need to make a mould for a hollow object, you should create a 3-part mould instead.