I'm trying to cut holes into a cylinder top. My first step is to create a cylinder. Next I delete the bottom face. Then I solidify it to give it a thickness of .05m.
At this point my object looks like:
Now I select the cylinder and add the Boolean modifier. I select the circle as my object and try to do a Difference operation. If I make the circle invisible, I see a hole cut into the top of the cylinder as I want:
Instead of a hole cut into the face, I have a hole with an extruded cylinder below the cut.