Keep in mind that you want to make half of a mold using the SIDE of the bust and then the other side, not the top half and then the bottom half.  You need to have the bottom of your master resting flush against one of the sides of the mold box.  If you have a way to properly suspend the master SIDEWAYS, with the bottom firmly touching a wall, then I guess you can do that.  However, I'd be really curious to see how you suspend the master sideways, always keeping the bottom tight against a wall without actually interfering with the mold process.

The clay acts as a natural way to suspend the master while also "hiding" the half that you plan to do next.

Hopefully I'm explaining this well enough.  It's hard to explain through text only.

Your other option, depending on the shape of the bust, is just to make one mold around the entire master and then taking an Exacto knife and cut into the mold, effectively splitting it in half to release the master.  Now you'll have two halves to use for your pours.  This method, however, only works on certain types of masters.  A small bust, as you've described, might be the kind of master that you could make a mold this way.

Best of luck with your project.

Last Edited By: sgiove May 19 12 10:55 AM. Edited 2 times.