Cut a Coped Joint in Wood Trim
The best way to make baseboard or crown molding fit together perfectly at inside corners is to cut a coped joint - a joint where one piece is cut square and the other piece is cut to fit over it, so that even if the corner isn’t square (and they almost never are) the joint will look tight.
Contents
Steps
- Start at an inside corner. Cut the first piece of baseboard square and nail it in place. Cut the second piece to length. One end will be coped to fit over the first piece you cut. The other end will either be left square if it ends at an inside corner or left long and cut to fit if it's an outside corner.
- Make a 45 degree miter cut. Bevel the end of the molding to be coped at a 45-degree angle with a miter saw. This will reveal the profile. Darken the edge of the profile with a pencil so it will stand out more when you cut it.
- Cut the profile with a coping saw. Angle the coping saw about 30 degrees to remove more wood from the back of the molding than the front. Then slowly and carefully saw along the profile. Concentrate on staying just outside the line. You can always sand or file away extra material.
- Test the cut. Check the fit of the coped piece. Mark any high spots.
- Fine-tune the fit. File or sand off high spots. Use rolled-up sandpaper or a rat tail file to fine-tune curved sections. File and sand until the joint fits tightly.
- Continue around the room. Cope one end and leaving the other end square.
Tips
- See the external links below for more detailed instructions.
- Try a practice joint first with an extra piece of trim.
- Don't twist the coping blade trying to follow a sharp turn in the profile - just cut that section out and start from another angle.
- Replace the coping saw blade if it starts to get dull.
Warnings
- Watch your fingers when sawing.
