Thanks everyone for answering my questions. I understand that most parts do not need to be solid and will only waste material. I was more concerned about smaller parts. I've downloaded Cura and will spend some time with it. One thing I noticed with Cura is that it will not import an STL part drawn in inches at the original size and has to be rescaled. I converted the part to mm and it worked. Perhaps they will address this issue at some point.