An overview to explain how we mold and cast our mask bases.
PLEASE READ the whole description! It explains all the steps, lists materials used here, and links to smooth-on.com where I buy my rubbers and resins.
I WILL NOT answer any questions the answers to which are in the descriptions or can easily be answered with a visit to smooth-on's website (or even a quick google search). I will also not detail this process further.WEAR CHEMICAL RESISTANT GLOVES, A RESPIRATOR, AND PROTECTIVE CLOTHING!
I'll say it again:WEAR CHEMICAL RESISTANT GLOVES, A RESPIRATOR, AND PROTECTIVE CLOTHING!
DO NOT DO THIS NEAR FOOD SURFACES! DO NOT EAT OR DRINK NEAR YOUR WORK AREA! DO NOT HANDLE OR USE THESE CHEMICALS NEAR CHILDREN OR PETS!
If I see anyone else blatantly ignoring basic safety precautions, I absolutely will take this tutorial down.
Description of steps:
1.) I start with a model in wax based plasteline. This model is done over a full head cast, but it could also be done over a face cast or any other form.
2.) I build up a rim around the sculpture, to create a retaining ledge for the silicone.
3.) Bits of clay to add support to the ledge.
4.) The head cast is laid flat and leveled. I am using a tin-cure silicone* to make the mold. Both parts of the liquid rubber are measured into mixing cups, along with a thickening agent to make brush-on easier**.
5.) The two parts are thoroughly mixed together, and then brushed onto the model. After layer one has cured mostly, I add a second layer of rubber.
6.) I quickly cast two rectangular pieces in the same silicone, which I will cut up and use to make keys (keys hold the floppy rubber more securely in the mother mold)***
7.) I add a third layer of rubber, and stick the key pieces onto the curing surface. They will permanantly fuse to the rubber as it finishes curing.
8.) Once layer three has cured, I brush on a fourth and final layer. When that layer is cured, I draw a parting line down the middle, to use as a guideline for making the mothermold.
Part B - [link]
Part C - [link]
* This is not typically the rubber of choice for a brush-on mold, and this rubber in particular is formulated to be poured. Also, it has a short library life in relation to a platinum-cure silicone, and is prone to tearing. However, it's a somewhat cheaper sort of rubber than a platinum silicone, and I get the brush-on to work fine for me. Also, a high mold-turnover rate is almost ideal for me, since I tend to update these molds often, anyway. But in general I recommend platinum cure silicones - Rebound 25 from smooth-on is a favorite of many.
** Although this thickening agent, in the case of the particular silicone I am using, more accelerates the cure speed than actually thickens the rubber outright. It works for me.
*** This is totally my own freaky way of doing keys. I have never heard of anyone else keying like this, and that's because it's just silly. However, it's fast and cheap, so I'm doing it, so there.
Materials used here:
sulphur-free plasteline (Jolly King brand)
OOMOO 30 from smooth-on
Chemical-resistant nitrile gloves
Paper cups and popsicle sticks (for mixing)
To learn more about the materials I'm using, and to learn more about mold making and casting basics, visit Smooth-On.com: [link]