Tuesday, January 29, 2013

How to Make a Mold for Silicone Casting

 So, many of you remember from last week that I did a pretty cool tongue sculpture out of oil clay.  Since it's a simple form and I am going to be casting it out of silicone,  I have elected to make a plaster mold.  Silicone doesn't really like to stick to much of anything but itself, so plaster is a good cheap molding option.  you can see here I started with a detail coat.
I quickly build a cardboard wall and seal the bottom and side with hot glue.  (Plaster sticks to lots of things, but it doesn't seem to like cardboard)

I fill it up the rest of the way with plaster.  You don't want to have too much time between layers because plaster expands and contracts at different rates.  If you wait too long you will get strata in your mold and the different layers won't chemically bond.  It would make the mold more delicate and prone to cracking.  If you have more than a few minutes between layers of plaster be sure to wet the mold with water before applying the next layer.
Now that it set up I flip the mold over

Because of the shape, the foam core of the sculpture pops out so easily.


The mold was still warm from curing, so the clay cam out without a hitch.

And here's the mold!

Next week: how to cast in silicone

Tuesday, January 22, 2013

SO You Want to Sculpt a SIlicone Tongue?

So, I took a month off from blogging for the holidays.  Apologies to the loyal readers who have been checking in.  I have, however, been working.  I am trying to work my body down to being only 50% Christmas cookie.  As you can see above, I got a pretty sweet phone case for my iphone.  I sent one of my new pictures off to Uncommon.com.  The print is a little dark and a little undersaturated, but still very nice.
As far as the masks go, I've decided to go a different route with the tongue and I am going to cast it out of silicone.  So first, I must sculpt it!

Checking for size

Alabaster foam

Rough cut with a utility knife

Coat of clay

Laying plastic wrap down I can use my pore stippler without gouging the clay

I made this tool out of super sculpey.  I made rounded stamp with pock marks in it so when I press it into clay it leaves bumps rather than holes.

Stamp stamp stamp

Lookin good.

use my embossing gun to smooth the clay without burning it.  Best investment ever.  Bought it over 8 years ago.  It looks like a glittery purple dildo, but  it can blast our over 200 degrees in a matter of seconds.  Works really well on oil clay and for baking thin layers of Sculpey.

Next week: Molding the Tongue for silicone casting!