Mould making tutorial, Part 3 - 1st clay side

The next step is to cover everything with clay. (Or with plastiliin, as the material I'm using is called here. But I'll use the world clay.)

The mould will consist from 4 details - two silicone sides and two part plaster shell. The first mould part I'll make will be one side of the plaster shell, so for now the clay should emulate everything this plaster side will touch.

First I cover the cardboard base with smooth layer of clay. This surrounding flat area will be later made from plaster, it will become the other side of plaster shell. Here I define how the plane between two rigid plaster sides will look. There couldn't be any undercuts!

Then I cover the statue with ca 1 cm clay layer. This will become silicone, the most important part of the mould, so it can't be too thin. But, it doesn't need to be too thick too. This part of the mould sculpting defines how the silicone will look. I don't smooth the clay up too much, as I'll clean and smooth the finished plaster shells anyway, before pouring the silicone. Statue is inside the plastic bag, as at the moment it is practically just a placeholder.

As I already said, the area covering the sculpt (the one with "ribs") will become silicone. All those details will fix silicone mould to the plaster shell and will keep it in place and from moving.

There's another very important detail to keep in mind - air vents. Actually, there are 2 clay details on top of each other (see next photo). First one is "funnel", connected to the copper tube/peg below the leg. It will become the channel for pouring resin in. This part is made of clay at the moment, but on finished mould it will be empty. It's covered with another layer of clay which will become silicone, surrounding this "funnel". There's also room inside the silicone for other air channels, one coming from other leg, another from fingers. It looks complicated, but it all will become clear later.

And this is when this tutorial became handy. When writing this text, I discovered, that I didn't make the "silicone" wide enough... I need to get another air vent from statue's left hand's fingers, or there will be no place for trapped air to get out. So I widened the area. The difference is visible on photos, last one is taken before the corrections.

So, this is how it all will (hopefully) work:

Of course, there's an additional joke in here - Hellboy's Ilsa character lost her life inside of Iron Maiden. And this plasticine cover looks very much like Iron Maiden...
:-)

Next: Part 4 - 1st plaster side