Learn how to make a mold and support for the nativity set. For this, you will use a 2-piece mold.
MOLDING OF THE NATIVITY SET
Materials and Tools:
- about 4 1/2″ model of nativity set
- modeling clay molded to a width of 1 1/2″
- 500g silicone rubber or RTV
- 25g catalyst for silicone rubber
- about 2kg plaster of Paris*
- about 600g water*
- masking tape
- 3g mold release agent or petroleum jelly
- 2 rubber bands (about 1/2″ x 24″)
- mixing bowl
- small knife
- modeling tools
*Add amount if model is larger
- Coat the sides of the model with modeling clay. Make sure the front and back of the model are divided equally. Apply clay to the holes between the back and front of the model. Pack well to ensure that the details of the figurine are properly reproduced on the clay.
- Smoothen the clay by means of a knife or any appropriate modeling tool. Scrape off excess clay.
- Using a round-tipped object like the handle of a paint brush, gently prick the sides of the clay to make shallow holes. These holes are intended for the locks of the rubber mold.
Now that one half of the model is covered with clay, make the other half of the silicone rubber mold.
B. Making the First Half (front) of the Model:
- Apply thinly the mold release agent or petroleum jelly to the exposed part of the model including the clay base. Wipe the surface with a dry cloth to ensure that the release agent is evenly spread.
- Pour 250g silicone rubber or RTV into the mixing bowl.
- Add 12.5g catalyst to the silicone rubber. Mix well.
- Apply thinly the mixture to the front portion of the model until the model is fully covered. Apply the remaining mixture. Let the silicone rubber mixture dry for 30 minutes.
C. Making the Support:
- Put a cardboard walling around the model making sure that the height of the cardboard is higher than the highest point of the model. Fasten with masking tape.
- Pour sufficient amount of water or about 300g into the mixing bowl. Add 1kg plaster of Paris to make a mixture with the consistency or viscosity of condensed milk. Mix well with the spatula.
- Apply the creamy mixture to the surface of the dried silicone rubber mold. Apply to all parts until the support is formed.
- Let dry for 25 minutes.