Miter or Cope
How do you cut crown molding to fit an inside corner that is greater than 90 degrees? I
How do you cut crown molding to fit an inside corner that is greater than 90 degrees? Is there a way to cope such a joint, or should it just be mitered?
— Mike Hart, Kiawah Island, S.C.
Norm Abram replies: Generally, those joints are mitered by dividing the corner angle in half. For instance, if the walls are 120 degrees to each other, each molding would be cut at 60 degrees. To make a 60-degree inside miter, set the saw blade at 30 degrees and lean the crown against the fence with its bottom edge facing up.
It's possible to cope the joints—cut out the profile in the end of one piece so it overlaps the profile of the adjacent piece—but the farther you get from 90 degrees, the harder it is to make the joint tight. So when a corner is greater than, say, 110 degrees, go with a miter joint.