http://www.smooth-on.com/crystalclear to see more clear resin casting demonstrations.
http://www.smooth-on.com/moldstar to learn more about the silicone rubber used in this demonstration.
http://www.smooth-on.com/aquarium for more custom aquarium design ideas using Smooth-On’s aquarium-safe rubbers, plastics and foams.
Making Your Own Conch Shells Using Crystal Clear Plastic
A two-part mold will be made using Mold Star silicone. Hot-melt glue is used to assemble a mold box out of acrylic sheets. A marker is used to trace the inside perimeter of the mold box. A clay base is then formed inside this perimeter using RAM Sculptex clay (available at http://www.reynoldsam.com/Tools,-Supplies-an/c1_1334/index.html). This clay base will divide the model into halves. Additional clay is placed inside the conch shell opening. The shell is then pressed firmly into the clay base. Clay is applied to the the parting line. Small acorn nuts are imbedded in the clay to form registration keys. The assembled mold box placed around the clay bed and affixed to the working surface.
Mold Star 15 SLOW is mixed 1A:1B by volume. The two parts are mixed thoroughly until a uniform color is achieved (no white or green streaks present). Mold Star 15 is poured into the mold box slowly and is allowed to seek its own level over the model. The silicone is then allowed to cure for 4 hours at room temperature. After this, the box is separated from the base and turned over. Clay is carefully removed and cleaned from the mold, the acorn nuts are removed, but the model remains in the mold. A pour spout is created with clay and attached to the model at the highest point. Ease Release 200 release agent is applied to the freshly cured silicone. A second batch of Mold Star 15 is measured, mixed, poured, and allowed to cure. Once cured, the two halves of the mold are separated and the model is removed.
For casting, the mold halves are reassembled using the keys for proper registration. Crystal Clear 200 urethane casting resin is mixed 100A:90B by weight. Parts A & B are mixed thoroughly then poured into the mold using a funnel to prevent spillage. The rubber mold is placed into a pressure pot and allowed to cure for 16 hours at 60 PSI (important: make sure the pressure pot lid is fully secured). This eliminates any bubbles in the liquid plastic as it cures. For a variety of casting effects, color can be added to Crystal Clear resin. For example, Ignite pigments will create fluorescent castings that glow under actinic light.
Make It Now! with Smooth-On
Post time: 04-27-2017