This week I am casting the first half of upper arm bones. These are split in quarters due to very complex organic geometry (basically they have a hole through them where the pistons go), so that they could be removed from a rubber mold without breaking them. Here are some pictures after first two quarters of wax casts were welded together last November to create a complete half (still in wax, with a wax pen), dipped in slurry and coated in sand. After drying, they were bunt out in a kiln overnight.