Thank you all!
I am impressed with your thoughtful and varied ideas. I want the capability of making such spheres more than once or twice, so some sort of fabrication plan seems appropriate rather than the ladle method. I like the idea of making my own ball stake and I would not have thouight of looking for a ball to start with from some supplier had it not been suggested. I will follow up on the links provided and get welding on that. Thanks again.
Vic