I helped Megan Fitzpatrick install the crown moulding on the case-on-case bookshelf that’s featured in the December issue of Popular Woodworking. Here’s how I do it:
When I have a large enough flat surface available, the first thing I do is turn the carcase over so that I have two flat surfaces against to reference , the carcase and the workbench top (or floor) .
Now, begin with the front run of moulding. With it inverted at your miter saw, cut one end. Take a piece of the cutoff and reverse the just-cut angle to create a mating piece. Position your front moulding at the case and align the two mitered ends to form your corner. Use a couple spring clamps to hold the front in place, tight to the carcase.
Slide down to the opposite end and mark the cutline flush with your case side (also mark the cut angle so you don’t get confused at the miter saw).
Swing the saw to the correct 45Ã?Âº angle and cut at the line. It’s best to sneak up on the line if you can. Your front moulding should be ready to install.
Back at the piece, position the front piece with the scrap to again set the corner, add spring clamps, then check the fit of the second corner , a second scrap needs to be cut to make the fit. If everything checks out, use brads to attach your front piece. Nail into both the case and the top.
Cut two pieces for the return moulding (on for each side) and cut opposing 45Ã?Âº angles on each piece. Fit those to the front piece and mark the cutline at the back of the case. These cuts are at 90Ã?Âº. With the return moulding fit and sized, add a small amount of glue to the 45Ã?Âº cuts and install the pieces to complete your mouldings.