I am trying to hang a pot rack, and my house is all plaster walls. I have an electronic stud finder but the places it is telling me that studs exist don't seem to be correct - test nails have gone through about 1/2 inch of solid before pushing the rest of the way in.
My plan is to find a joist, and either screw into it or run a 1x2 between 2 joist and screw into that. Is this the right approach, and if so how do I find the joists?
Update: I went back at it with the stud finder, getting inconsistent results. Tried bucky balls (the only magnet I have around), which didn't locate anything. I went back to the most reasonable location for the joist and sent in a 1.5 inch test nail, which felt snug most of the way. I got a longer, wider test nail (2.5 inches) and it cleared everything very easily, but then met with something solid once it was about 2.25 inches in. I got a longer nail, about 3 inches, and it seems that it is solid wood there.
A) Is it plausible that the joist is that far from the surface of the ceiling?
B) If that is the joist, do I need to do anything special to account for the extra distance? Am I just trying to find a hook with a 4 inch screw?