Saturday, August 29, 2009

Learning to Cope- A Technical Tutorial

Finally, I have decided to post about something I actually have some knowledge in: carpentry.

In the past couple of years, I have been asked by several people something like "Have you ever seen trim that isn't just cut on angles? It looks like they did something special? What is that, and how do you do it?"

Here's the answer: It's called "coping", and though intimidating at first, it's very simple once you know how. Coping is only used for inside corner joints- baseboard, crown moulding, chair rail, etc... and in this post I'm going to show you how to cope with trim so you can impress all your friends at dinner parties. Chicks dig it, too...
Step One (above): Cut an inside 45 degree bevel with the trim lying flat on your miter saw. You should see a pretty profile of the moulding's curvature, but don't get too impressed with yourself yet, we're just getting started.

Step two (below): Using your coping saw (guys, I know you all have one, though you may not know what it's used for), begin to saw, following the curvature of the trim. Notice I am not cutting 90 degrees to the piece, but instead I'm using some back angle to ensure the face is the point that meets the other moulding. TIP: Have patience, let the saw do the work, or you'll have tear out or cut into the face.

Step three (below): Notice that there is still a little natural wood showing on the cope. That's intentional. Now you need to get out your rasp (a file for wood) and make this joint a work of art. I use a rasp that has both flat and convex edges. The flat side is used for flat filing, and the convex for curves. Again, notice the back angle of the cut.
Finished product (below): We are now ready to fit the pieces, which is another thing entirely. But you can see how the profile has been cut so that our little guy will fit sweetly over another piece of the same moulding. You can see that tools involved: coping saw and rasp.
Below: A coped joint when done well, is indistinguishable from a miter joint and far superior because you can get better nailing and it won't open up as easily. A good carpenter should almost always use this method of running trim; it's a tell-tale sign of them not being a hack.

1 comment:

Jodi said...

I hate hack carpenters...

word ver. :propsu as in "Props U". Man this teenage lingo I hear every day just sticks like glue in my brain