This a random shape made of three pieces of foam cut on a scroll saw and glued with a low temperature hot glue gun. The XPS foam is Bastion brand (made in Turkey) from the hardware shop that rhymes with Cool Runnings. I used Gyprock Multi-Purpose Joint Compound as the coating. The aluminium is A356 recycled from industrial gearbox pistons. The piece weighs 2kg. It turned out better than I was expecting although I'm not sure what the little rice bubbles are on the bottom of the casting (last photo). I think I'll use a hot wire cutter next time as there are noticeable lines from the scrollsaw's cutting action.