Finished up this latest bowling ball- holds over a quart of just about anything. Stainless steel and copper liner, cork to plug the opening in the thumb hole. It makes perfect sense.
Process shot of the hollowed out bowling ball, with the liner I put inside before reassembly. Liner is a stainless steel saucepan that I brazed shut and soldered a copper pipe to, at the necessary angle to fit through the thumb hole.