I made a sculpture out of non Harding wax based plastelina modeling clay. Yes I realize that that isn't what its intended for but I didn't know how long it would take me to finish. In fact it took me over a year. Now, I want to make a permanent statue of it so how can I make a mold? I was thinking oomoo or mold star but never done this before. The cheaper the better but it needs to work. I don't want to risk ruining the sculpture. Thanks.
First you have to know what material you want the duplicate to be. Clay? Plaster? Resin? what have you
I double checked the clay packaging and it says"compatible with silicone mold compounds. Contains no sulfer." So i'm thinking a low viscosity platinum silicone pour mold is my best bet. As for casting material, i'm not really sure. On one hand I'd love if it had a metallic feel to it, but for practical reasons its probably better to just use a plastic resin. I was thinking something like bondo (car body filler) might work as well since its a car i'm casting but I don't know if that will pick up the detail of the mold. I can always just give it a metallic finish when I paint it. the only requirement I have I guess is that I don't want it to be a solid block. Since its a car it should be Hollow. Maybe something I could brush on or something that cures fast that I could just spin around the mold and let it settle. I'm open to any suggestions. Something I can paint and make it look metallic. Something I can sand down and make very smooth. Something relatively inexpensive. Oh last thing, there are some parts of my sculpure that are only there for structural support that I don't want in the final product ,so whatever I do, i'm going to have to be able to cut off a part of it (or just not cast that part) and be able to redo it with clay the way I want it. Basically the underside. Imagine a crocodile all four legs on the ground but because its made of clay I couldn't work on the belly so the underside just goes straight down to the base. I'd like to cast the top, remove that base, sculpt its belly and then mold and cast that. Sorry I know that's complicated but its the best analogy I can make.
Sounds like you're going to have to make the mold twice. Once to get a model you can work on and a second time for the finished design. I'm partial to carving plaster, myself. Seems to me the best idea would be to make a rubber mold, cast plaster, use the plaster to perfect your model and then use that to make another rubber mold for pouring resin. You can always slosh resin around in a mold (if you provide it with a rubber plug) to get a hollow item.