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Silicone
*Responsible for all mold-fabrication
Dog Head Molds
The Dog head is comprised of four parts: head, nose, and ears (2), each part was molded in GI-1000 silicone, as two part molds set up for foam casting. Each mold features various registration keys for clean casting and to support the puppet head core for animation. Trenches are planned for before molding, to ensure there is enough room for them, but these are cut last from the mold once cured.
1/2: First Half
The Sculpts are first sprayed in Krylon Crystal Clear, and then oil based clay, Jolly King, is used to build up the clay up around the sculpt. Since each part would need to key into the main head, each mold was prepared with the necessary registration to support the core/armature when casting.
Plastic cast sphere keys, and sculpted keys were added to ensure both halves locked securely together. and foam core walls were placed around the perimeter of each mold. Silicone is activated, degassed and slowly poured into each mold ensuring a thin stream. Since these are for foam casting, I used silicone chunks to help fill these molds slowly adding them into the corners of the molds, before stopping to make sure each one levels out smoothly with the silicone pour.
2/2: Second Half
Once the silicone had set for the first half, each half was flipped and the Jolly King was carefully removed from the models and cleaned. Before resetting the walls, each mold was brushed in vaseline to prevent silicone from bonding in the event of any leaks. Jolly King clay was used to fill the seams of the mold to the foamcore walls and the surface was once again brushed in vaseline and buffed right before pouring the second half.
Final Head Molds
Dog Head Mold
Preparing for Registration
A simple one part mold was made of the Dog head and nose in order to drill the head and the nose to ensure that they would align accurately with each other. This also allowed a more precise imprint of the Dog nose into the head so it would key in. A total of 4 jigs were made for the head, at the necessary angles that needed to be drilled so that the registration could be added.
After jigs were made, the head could be drilled. I ended up drilling all the way through the dog head using a 28 size drill bit on the drill press, and into the nose with a 36 size drill bit from the back of the head with a hand drill. I drilled just enough to 6-32 tap into the nose for a few threads to add my screw for registration. And then I taped the front of the dog head for 10-24 screw registration after closing the back of his head with propoxy.
After the second half cured trenches were cut out of one half of the second half of the mold, these trenches will allow the excess foam while casting to flow out and prevent over-compression of the material as it expands. Careful to avoid cutting the registration keys or model by leaving roughly 3/8th of an inch of space from them.
Frog Head Mold
Frog Head Mold
The Frog head mold is a two part silicone, molded in GI-1000. It sports a combination of sculpted keys and delrin balls to ensure clean cast foam models, and brass tubes to center the core of the puppet head during registration. Trenches were planned for before molding to ensure space, but cut into the second half of the mold after curing.
Beginning Clay up
First half poured
Second half prepped with foam core corral
Second half poured, drawn trenches
Trenches cut
Clay-Up:
Pouring Both Halves:
The Sculpt is first sprayed in Krylon Crystal Clear, and then oil based clay, Jolly King, is used to build up the clay up around the sculpt. Because the puppet would be covered in needle felt, I decided to add multiple animation ports which worked well as registration for the head core later when casting. Plastic cast sphere keys, and sculpted keys were added to ensure both halves locked securely together.
Foam core walls were placed around the perimeter of each mold. Silicone is activated, degassed and slowly poured into each mold ensuring a thin stream. Since this is for foam casting, I used silicone chunks to help fill these molds slowly adding them into the corners of the molds, before stopping to make sure the surface levels out smoothly with the silicone pour.
Final Head Mold
Gregory Head Mold
Gregory's head mold is one part, with careful orientation and planning, I planned my cut line down along the crown of the head as the widest part of the head and away from the delicate facial details. Once cured, a jewelry cut is used to open the mold as little as possible while being able to remove the model. While the jewelry cut will provide registration keys for aligning and closing the mold, it is important to straighten the cut closer to the model to minimize the visibility of the seam in the event of any thick flashing.
Gregory Head Mold
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Corral Assembly & Silicone Pour
Head has been sprayed with Krylon Krystal Clear after removing the eyebrows and pupils which will be fabricated separately with the plastic cast. The neck has also been filled in with the center position marked for head drilling. The foam core corral is then hot glued into place based on mechanical.
The corral is placed at an angle while pouring to avoid trapped air bubbles and the silicone is poured at a thin stream after degassing. Once the model is completely covered in silicone the mold is leveled and finished pouring until the marked fill line.
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