MOLD MAKING - Silicon rubber mold
- silicon rubber
- modeling tools
- ice cream cup
- basahan (cloth rag)
- modeling clay
- blade cutter
- small basin
- petroleum jelly
- plaster of paris
- nylon brush
A. Preparation of one-sided silicon rubber mold
- Prepare original model (preferably intricate designs such as animal figures, birds, fruits, etc.) and apply petroleum jelly to the surface of the model.
- Put clay barricade around the prepare model with ½ of an inch allowance in every side. Set aside.
- Prepare enough mixture of silicon. (Ratio: 100 grams of silicon + 5 ml of catalyst)
- Using a stick, apply first coating of silicon mixture evenly to the surface of the model. Use only half portion of the silicon mixture.
- When the first coating is almost dried up, apply the other half portion of the silicon mixture on the first coating of silicon.
- Set aside and wait until the silicon mixture hardens like a rubber band. This will take about 1 to 2 hours.
B. Preparation of plaster backing - using Plaster of Paris
- Do not remove the clay barricade and model inside the silicon mold.
- Prepare enough mixture of Plaster of Paris. (Ratio: 1 cup of water + 1½ cups of Plaster of Paris powder)
- Sprinkle the Plaster of Paris into the container with water and let it stand for one to two minutes.
- Stir until the mixture reach the consistency similar to that condensed milk or cream.
- Pour and apply evenly the plaster mixture on top of silicon mold.
- Wait for 6 minutes or until the plaster hardens.
- Remove the clay barricade, then the plaster backing.
- Invert the mold upside down and remove the model inside the silicon mold.
- Trim with scissors the side of silicon rubber mold. Set aside for casting.
Moulding of decorative wax
- Melt 4 kilos of paraffin, 200 grams of polyethylene wax and 200 grams of crystal wax.
- Prepare the silicon rubber mold. Remove all the impurities.
- Put the silicon rubber inside the backing.
- Pour the melted wax mixture into rubber mold.
- Wait for 15 minutes or until the wax mixture thoroughly dries and becomes hardened.
- Remove the formed wax from the rubber mold and trim with knife.
- Paint with oil color, and then spray with acrylic gloss lacquer to make the object shiny.
source: mis.dost.gov.ph, picture from www.bandrdesigns.com