Thanks Jim for the quick reply and thanks for the welcome. I didn't make it explicit, but my question was about the 3D Printing Tools addon WB tool bar icon which does say "Mesh->Solid". I had been playing around with the functionality of the Part WB as you described but then I discovered ...

Hello mark1791, The "Mesh -> Solid" operation does not seem to create an object which can participate in boolean operations as a solid. I had to further process the newly created object with the "Advanced utility to create shapes: Solid from shell" from the Part workbench. I'm ju...