Completely siliconed head.

Covered with plastic. The beginnings of the "mother mold".

Building a shell of expanded foam around the silicone.

Then I made a "mother mold" out of MDF and can-foam to hold the molds shape. 

The silicone mold.

After spraying a mold release agent into the silicone mold, two-part expanding foam was poured into the mold to create a replica cast.

A similar process was used to cast the horns.

The complete foam head.

Please continue reading page 3 of Scott's tauntaun costume.