Ed, this woman describes the process that is used to make her metal sculptures. I'm not sure if it's the same process that Shapeways uses.

http://bathsheba.com/sculpt/process/

The 3D printer lays down layers of stainless steel powder that is held together with a laser-activated binder. The sculpture then goes into an oven for a while. The sculpture's stems are then dipped into molten bronze where capillary action draws it up into the sculpture.

Steve S