Working with fast setting Polyurethane Rubber, a two part equal A and B mix. I thickened the liquid with 'Fumed Silica' to increase viscosity, allowing me to cover the whole surface of the sculpt in a shorter amount of time and to minimise pooling around the base.
After several layers of rubber I split the mould in half by building a mould wall out of clay. This creates a seam for the 2 part mould jacket. I then cover each section with epoxy putty (car filler) and strengthen it with hessian, This creates an extremely durable, lightweight mould jacket.
After the mould jacket has set, I then separate all sections of the mould. Making an incision along the centre line of the rubber to allow me to remove the clay from the inside of the mould.