Coping Mouldings ... Does it even have to be a question?
I've always considered coping to be the "standard" for joining the inside corner of mouldings. That's what I was taught. Whether it's baseboard, chair rail, crown moulding, etc., in my view it is proper procedure to cope all the inside joints of any type of moulding. I don't even remember questioning it, we just did it. Back in the day, if someone just mitered all their inside joints it was considered to be lazy, a short-cut, the wrong way to do it.
It seems to be a lost art nowadays, at least around this area. I'm noticing more and more that no one seems to cope anymore. In the past, it seemed rare to find someone just mitreing all their corners, now it's rare to find carpenter's who cope their corners.
A few months back I was on a jobsite talking to a lead carpenter for a trim crew and he actually laughed and made fun of the fact that I coped my trimwork. He just thought that was the stupidest thing he had ever seen. Nobody on his crew even owned a coping saw, never mind used one. I honestly believe he had never even heard about the technique before.
What's ironic in all this, is the fact that I lose contracts to companies like that. It seems that neither the builders nor the homeowners seem to care or know the difference anymore.
I have even noticed a lot of these, do it yourself how to articles and videos instructing people to just mitre the corners. It's frustrating when you see a television show, and they are just mitreing all the inside corners, then to top that off you see them installing the crown moulding upside down sometimes. What have things come to? The other day I was at your local big box supply store and they sell a book on crown mouldings that blatantly discouraged the practice. In my view, when he did describe the coping process in the book, it wasn't anything I have ever done. I would be firing people if they tried to cope moulding like he described. It isn't any wonder he discourages the practice.
Now there are instances that you need to mitre inside corners. I will mitre them if they are really short returns. Usually under an inch or so, for instance around keystones, mantels, pilasters etc. And another example is certain types of crown mouldings don't cope well, some have almost negative angles on the profiles that are impossible to cope without cutting into it. Another example would be certain conditions encountered on cathedral or vaulted ceilings.
This article seems to be one of the better ones I have found to date concerning the practice: Coping Moldings
Whether or not to cope mouldings... not a even question in my book, and never will be.