Clean edges against the wall
Screws in shoe so there will be a hole in the mold for the tie-down
Sculpt: The original sculpture (That I spent 14+ fucking hours working on)
Mold: framework or shape used to make an object of complementary shape from a pliable material: http://en.wikipedia.org/wiki/Mold_(manufacturing)
Molding Material: The material the mold is made out of, in this case it will be Hydrocal (more to come on that)
Cast: The final product; what I will have after the mold is created and I’ve poured the casting material into the mold as a liquid and allow to solidify (more on this later), it will have the exact shape of the sculpt.
Casting Material: What the final puppet (at least the portion that comes from the mold; you’ll notice the head is not being molded) is going to be made out of.
Releasing agent: Something put on to the sculpt (or anything) with the purpose of making the de-molding process easier, so that when the molding material has hardened it will be easier to take the sculpt out.
MOTL: More On That Later
Key: Part of the mold made to register the two sides of a two part mold.
Ball kickin fun! There are a lot of things that need to be decided early. The first is what is my casting material?
I have decided to cast my puppet in L-200 Casting Latex. I'm using latex because it's a good rubbery flesh like material, but most importantly because it's free to me through NYU. (The L-200 part is not essential, I've just decided to put it in so people can look it up and so I'll remember myself. You're welcome happy people!)
The latex will be mixed with acrylic paint in a 60% Latex, 40% acrylic paint ratio. (More latex than paint because I'm tinting the latex; and if you put too much acrylic in the skin starts to crack with too much stress and movement.)
Because I'm casting in Latex and need a molding material that will allow the latex to set and dry. I've made a ton of silicone molds, they're beautiful. However, latex will not set up in a silicone mold. It needs a porous material to dry, otherwise it's like it's in an air-tight container and will never dry. This is why I've decided to use Hydrocal, a plaster like material. Hydrocal is better than plaster for molds however, it's harder and heavier. There are many disadvantages for hydrocal (versus silicone) and I will probably never use it again. I used it because it's cheap and because I needed it for latex (which I used because it's free to me.)
Okay, I had to make walls for the mold. First, I cut the green klean clay with a removed OFLA blade. They need to be straight, hard edges. The walls were made with foamcore (I was also informed that lego's would work, and I really wanna try that some time.) I used the flat factory edge of the foamcore for the bottom, then I just measured the lengths of the edges and cut one side of the foamcore, so that one side is preserved and the other side is cut (obviously the preserved side is the side facing the clay.) This way I have a clean piece of foamcore paper all along the edge, making an open box. I used glue gun glue to secure the edges of the wall, both to each other and the bottom foamcore. The hot glue is really good for sealing the walls.
You'll notice that the green clay is right up to the edges, I had to add more clay at those edges to make it a clean, straight, level edge.
At this point I sprayed everything, including the green clay, again with crystal clear, so all of the clay would release easily from the mold when done.
I also put the screws so that there would be an open hole so that when I'm ready to pour the latex there's room available for the screw needed for the tie down.