Week 11

Molding and Casting

This week we got to try out making a mold, out of an object that we brin, using silicon, and then casting it using plastic. I’ve decided to bring a gear from a project of week 4. It was made on a 3D printer and it had a lot of small details and it was ineresting to see how well the silicon would transfer them into casted plastic.

At first I made a cardboard box, using sculpting plasticine, to fit the gear and make a casting mold. Then we’ve prepared a 1:1 solution of Dragon Skin 10 silicon and it’s activator. and poured into the box with the gear inside.

Creating a silicon mold for a gear using Dragon Skin 10

After waiting for about 25 minutes, the silicon hardened and I pulled the form out. Then, in the same procedure as for molding, we made a batch of casting hard plastic called Smooth-Cast 305 with a bit of a pink pigment. Poured it into the mold, and after about 30 minutes the gear was completely rigid and could be taken out.

Original gear, silicon mold, cast plastic gear

In the end, the cast actually kept an insane level of detail of the side on which the gear laied on, which I didn’t expect. Otherwise, I can say that this could be further improved by using a more solid molding silicon, that would keep more precision of the shape of the gear, using a harder plastic because the resulting gear could bend a little bit after applying hard pressure. And preparing a mold that would have both sides of the gear covered, because my gear had the side that was pointing upwards, basically have a textured of a solidifed liquid.