TIM MARTIN: Okay, so now onto keys.
The way you make keys, really simple.
Take your clay,
not quite as thick, maybe half an inch.
If you have a clay board that helps out a lot.
So now I have a thin sheet of clay.
And I'm only going to make 3 keys.
So I'm going to cut a strip
at a 90 degree angle,
then the other one about a 45 [degree angle].
So you can see that I have a 45 degree angle on one side,
90 on the back.
90 isn't important because it's going to be on the outside of your mold.
So again I'm going to do another 45 degree angle cut,
45 degree angle cut
and that is a key.
That's what a key looks like in clay.
So it's a lot deeper than it needs to be, you'll see why.
I'm going to press this really close to the edge of the sculpture
and then cut it flush to my wall.
So I've got this teeny tiny little key.
That keeps, the three of these are going to keep my mold from shifting against itself
when it's no longer got a sculpture in it
and you're trying to cast it up.
Clean that up a little bit.
And the reason you cut those edges at an angle,
is because that angle makes sure that these mold walls don't lock into themselves.
If you did square keys, they're probably going to break.
You can do a few, depends on the size of your sculpture.
I'm doing three,
the top and the two sides.
So I said "about a 45 degree angle"
don't worry if it's not exact,
you don't have to sit there and
calculate or measure it somehow.
Just eyeball it.
And it looks really small, but this thing is going to be so important.
My final key is going to go on top.
This one I can make a little wider, actually.
So I made it a wider key but it'll still be really shallow.
Okay, so that is going to go right on top.
Clean that off.
Okay, so that's the end of our clay.
Using my same sponge, cleaning up these
edges of this key a little bit.
Now thinking ahead a little bit,
what I'm going to do is eventually when the mold is taken off,
I'm going to then place it inside a bucket upside down.
And that's how I'm going to fill it up.
If you don't have a bucket,
what you can do is, you can build the top of your wall a little higher
and then cut it completely flat,
so that you still give yourself an edge
but the top of your mold is flat.
And what that does is you're basically preparing to, then
when the mold is opened and cleaned up,
you'll flip it upside down,
you'll have a flat edge to rest it on.
A lot of old school mold makers can sometimes,
they put wooden dowels in their molds
so it'll have four points,
basically you just set that over just like a table
and that'll rest on its own.
But, we're doing the quick and dirty version
so we're not going to be doing that.