The second sculpture to complete this artwork is a portion of a boat propeller.  I acquired a propeller, made a silicon mold, then wax model, then plaster mold and filled the cavity with glass.  Technically, it was my aim to fill the blades completely with glass.  Visually the glass propeller works well for the overall concept so I used it.  The images are a selection of the process.  This overall sculpture has been submitted for a conservation show, and I will post the complete images after I have heard back from them.