9. Install Crown Molding on a Mock-Up Corner

Objective:

Students will learn how to measure, cut, and install crown molding on a 90° mock-up corner using miter and coping techniques.

Materials Needed:

• Crown molding (wood or MDF), enough for two inside corner pieces

• 2x2 or 2 x4 mock-up corner frame (2 walls joined at 90°)

• Miter saw (or miter box and hand saw)

• Tape measure and pencil

• Wood glue

• Finish nails or brad nails and nailer

• Sandpaper

• Caulk and putty (optional)

• Paint or finish (optional)

Instructions.

1. Prep the Mock-Up Frame:

Use two 2 x2 boards or panels joined at a 90° angle to simulate an inside corner.

2. Measure for Crown Molding:

Measure the top of each wall and mark crown molding length on the back side (the wall side).

3. Cut the Molding:

Use a miter saw set to 45° to cut inside corners. Optionally, use a coping saw to cope one end of the molding for a tighter joint.

4. Test Fit:

Dry fit both pieces against the mock-up wall to check for proper fit and clean joints.

5. Attach Molding:

Apply wood glue along contact surfaces. Nail the crown into place along the top and bottom edges.

6. Finishing:

Fill any gaps or nail holes with wood putty or caulk. Sand smooth, then paint or stain as desired.

7. Present and Reflect:

Show your completed corner and explain your process and how you ensured clean cuts and joints.

Reflection Questions:

• What made aligning and cutting the crown molding challenging?

• Did you use a mitered or coped joint? Why?

• How can you ensure tight-fitting joints in future projects?

Project Rubric:

Score /20