As my character is a pianist his hands are very important and I wanted to be sure that I could animate them in a way that would look great and hold it’s shape better than plasticine hands. I immediately knew that casting silicone hands would be amazing and if I could pull them off, they would be a brilliant addition to my character. I’ve never used silicone in anything before, so was initially unsure of how it worked but with the help of the internet, books and friends I was able to get a pair of (dodgy) hands.
The first stage was to model the hands themself. Plastaline is a material similar to plastacine but has been developed especially for the casting process. Grey plastaline gets harder depending on it’s temperature – malleable when warm, solid when cold – white plastaline is soft and extremely easy to mould. I used grey plastaline around the armature fingers/palm to make a hand that could be cast. As plastaline is an oil based substance, to smooth it out I used a tiny paintbrush and some linseed oil. The final stage was the add in the tiny details, finger nails, finger and palm creases (modelled in with a pin) and to make sure that they were as hard as possible I put them in the freezer overnight.
To create a box suitable to cast them in I used legos for the walls. This seemed like a better idea rather than using a tub or foam board because I would be able to slowly take the walls down without worrying about it all falling apart once the plaster had dried. As I mentioned above, I used white plastaline to fill up half of the mould at the bottom. After pressing the frozen hands into the plastaline as much as I could, I built the plastaline up a bit more so that it reached half way up the sides of each hand. This way when the plaster is poured in I would have an exact half casting of the hands.
A very important part of casting using plaster is to create what is called keys to make sure your two moulds fit together perfectly. These keys can be anything from a marble pushed into the plastaline to create a crater or they can be build up from plastaline. However you choose to create your keys doesn’t matter really, as long as they’re there and there is a few of them. I chose to just do four simple plastaline keys in each corner, to make 100% sure that my moulds would fit perfectly together. Another extremely important factor or casting is to make sure there is some sort of grease in-between the sections every time you cast. This is simple enough and I just made sure to cover everything in a good layer of vaseline before each stage.
Once the plaster is dry you have one half of your mould complete! I just repeated this process using the first mould as a base instead of the plastaline and after another over night drying session both halves were complete and ready for casting.
Finally the only step left is casting the silicone. Silicone is generally white, so to make it the same colour as my characters face I added the same coloured acrylic paint into the mix along with the curing agent. You can buy special silicone coloured dye but the silicone dye I was given by a friend was unfortunately completely different to my characters face. I poured it into my moulds along with the armature hands (I’d removed all of the grey plastaline off them as it was no longer needed once the mould was done) and left it to dry. I actually hadn’t added enough curing agent so when I checked on it in the morning nothing had changed – I scooped it out, added more and left it again to dry.
The results were not has good as I had hoped, in fact they were far from my expectations but for my first casting I guess they have come out okay. You can see that parts of the wire armature hand have not been completely surrounded by silicone. If I had more time I would have ‘skinned’ the mould which is when you paint a thin layer in first, let it dry and then fill it in completely – this helps to prevent the wire poking through anywhere. I will definitely cast them again to help the puppet look more complete but I need to stick to my project plan and the next stage is filming!