Sculpture class just had an quick Critique to review which of their three maquettes would be used to create a two-part rubber mold. One student was very enthusiastic about her three designs (notice the sketches too)! The finished result is ready for resin, look for the “Parting line” post that discuses the creation of a two-part mother mold.
After our critique, students chose one of the three maquettes to make into a mold. Pictured, this student has created a parting line that is exposing only half of the modeled object, key-ways & a sprew (proper spelling/pouring spout) are added and a side wall of clay so the rubber doesn’t run off the mold. This student is almost done (after finishing the clay wall) and will add a sealant to the clay for clean release from the rubber. Plaster is the last step after the rubber, but they will be repeating the process on the other side; hence a two-part rubber/mother mold.
Students started mixing rubber today (2-part/Smooth-On) and applied two coats to the one side of their mold. After that they will be adding a final back-up layer of plaster before they flip the mold over and repeat the process on the other side. We also explored different material options for casting into their molds. Plaster, wax, and Smooth-On products were discussed while other materials such as chocolate and crayons were also noted alternative options.
Mold Making demo consisted of understanding the different types of rubber (silicon vs. urethane) and what material cast in the mold determines which rubber is used. This is a two-part mother mold, titled because it utilizes plaster as a support structure for the rubber. Finally, I pointed out to my class that a master key way (3rd image, bottom left) helps orientate the mold properly.