After the cracking of my plaster cast i decided to make a mould from silicone. This would avoid any removal issues I may have.
I re sculpted the face the same as before and made a mould barrier from plasterscene, i then used 100g of silicone with extra fixative in it, to avoid it from running off instantly. I let this set and added a layer of plaster bandages to make a support casing for the mould.
Once fully cured i used plaster bandages to help the mould hold its shape. once it was fully dried i pulled the halves apart and removed the clay. I started to paint latex into the mould layer by layer.
Whilst it was drying i noticed the latex shrinking and pulling away from the silicone mould. After this started i decided to abandon the process. for future reference I know that you cant cast latex from a silicone mould.