I recently documented this project i worked on, making a mould for a giant head by for Artist and Sculptor Hywel Pratley, in his studio in London.
The images below, show the first stages of the project. Silicon are layers applied to the head, a very large surface area to fill. A number of thixotropic layers of silicon are needed to make the mould a sufficient thickness.
A plasti-shim wall pictured below, is inserted into a silicon bead to make the mould division lines, so that the mould can come apart in clear sections. All the undercuts need to be filled with silicon in order before I can make a fibreglass casing around it.
For the next step, a fibreglass mother case is made on top of the silicon, again in sections so that the pieces can be assembled to make the whole. The mother case cradles and supports the silicon while it is being cast.
Once the fibreglassing is complete a wooden frame is constructed around the mould to support it and all its sections while it is being cast, and ensures that all the mould pieces line up beautifully, leaving very little seam lines.
Once all the component parts are complete, I proceed to de-mould (take the mould apart) to reveal the original sculpture beneath. The mould can now be cleaned up and re-assembled for casting. A wonderful project to work on as I was working on site at the artists studio. The sculpture was so striking and photographs really well.