Hi, guys. A couple years ago I put up crown molding and picture rail molding in my home, which has plaster walls on 3/8" lath. (It's the original 90 year old plaster.)

Finding the studs was a chore, because the studs are often not at even intervals, and sometimes the lath has separated from the studs, so tapping with a mallet or probing with a nail doesn't work well. That electronic stud-finder gadget (I forget its name) was even less reliable.

Now I want to put up chair-rail and picture rail in another room, and I'm looking for a better way. I'm toying with the idea of using some sort of tool to cut through the plaster just deep enough to graze the studs. The groove would be hidden behind the molding, so I'm assuming I would not have to fill or patch it.

What problems would I have with that plan? What would be your tool of choice if you were to try it? Other suggestions on how to skin this cat?

Many thanks in advance.

Regards,

John