Thursday, October 6, 2011

Making a Stop Motion Puppet (Part 2): De-molding and Casting

This is a follow-up post to THIS POST.

After rubbing a little Vaseline onto the finished half of the mold as a release agent, I built another clay wall and repeated the process.

In the morning, I peeled off the clay around the outside and put it back in the back in the bag to use it again later. (Recycle, Reduce, Reuse!)
Using a couple screwdrivers and some elbow grease, I pryed two halves apart. The back half came of all nice and clean, but the sculpt stuck really hard into the front half. I ended up having to go at the orginal sculpt with a hammer and chisel to get it out of the front. Here is what it looked like after like 10 minutes of chiseling:
I ended up not being careful enough in my chiseling and made a few pretty gnarly scratches on the mold. There were also a couple bubble spots. But otherwise it came out pretty nice for a first try:
I'm using Smooth-On's Dragon Skin silicone as a casting material, with an armature wire skeleton. Because the Dragon skin is pretty pricey, I wanted to do a quick test to try it out. So I filled just the hand with silicone and used the armature from the original sculpt that had been chiseled clean.

I was lazy and added the color once it was already in the hand, so I didn't mix it very well and it ended up looking like this:
But that was fine to do a little test animation with some Helping Hand parts using my webcam. It's pretty quick, so you might have to watch it a couple times:

Excited that it was so easy and fun to use, I went on to doing the whole puppet. First I applied a thin layer of colored silicone to the entire mold:

Then added another few layers...
Then made a new armature based on how the silicone fit in there. I went with thicker armature wire and used some coper tubing around the leg bones because I was worried he would be too heavy to stand on his own. Then I used some plumbers epoxy to stick it all in place:
Also, because I knew that his fat old stomach would be incredibly heavy if it was solid, I cut up some kitchen sponges and painted them with a layer of silicone to use as flexible filling:
I then put the armature in one half and did a quick pass of silicone over it to make sure it really stuck in there with no slipping.
Then I put the stomach sponges on, poured in way too much silicone and put the halves together. What came out was this:
And after a quick trim of the extra stuff, I had a little guy!
There are some pretty obvious problems with the quality of the mold. Mostly I was too rough getting the original sculpt out of the front half, but I also didn't put enough silicone into the feet, and one of the hands. I also need to work on minimizing the size of the seams, which a cleaner mold would probably help with. Overall, if I was using this guy for a short film, I'd want to start from scratch from all I learned on this first go. But for a first try, I'm pretty stoked. Now I'm going to give him some eyes, a moustache, and a little costume, and then I'll make some test animations. I'll post them as I've got 'em....


  1. What a rad little puppet! I love his little spongey belly! Can't wait to see his costume :D

  2. Hey, great work. As you mentioned, Dragon Skin is not cheap. I'm gonna buy this silicone for my puppet, but I wanted to ask you what hardness did you use? Shore A 10, 20, 30 or Dragon Skin FX (but it's veeery soft, only 2A)? What hardness is best if you want puppet's fingers to move easily but also don't want it's head to became a gummy bear-like?