Fixed shelves bolster the structural integrity of a bookcase, but since they cannot be moved once they are installed, you need to give careful thought to their location. You can mount fixed shelves quite simply by screwing them to cleats that are fastened to the back and side panels. Your bookcase will be stronger and more attractive, however, if the shelves are attached to the side panels using one of the joinery methods shown below.
If you do not intend to add a face frame to your bookcase, remember that some of these joints will conceal the cut made in the side panel for the shelf.
Cutting through dadoes in the side panels is one of the quickest ways to join a fixed shelf to a bookcase. In the photo above, the side panels are clamped together with their ends flush, allowing two perfectly aligned dadoes to be cut at the same time. A straightedge jig guides the router through the cut.
Preparing the side panels
The half-dovetail dadoes in the side panels are routed in two steps: first with a straight bit, and then with a dovetail bit. Install a straight bit of the desired diameter in your router. Clamp the side panels edge-to-edge and inside-face-up to a work surface; make sure their ends are aligned. Clamp a board against the stock at the end of the cutting line to prevent tearout. Also clamp an edge guide across the panels, offset to properly locate the edge of the router base plate and the bit. Starting at one edge of the panels, feed the router across the stock, pressing the base plate against the edge guide throughout the cut (above). Complete the dado by making the second cut with a dovetail bit (inset), shifting the edge guide away from the first cut by one-half the dovetail bit diameter.
Preparing the shelf
To create mating half-dovetail tongues on the ends of the shelves, leave the dovetail bit in the router and mount the tool in a table. Position the fence for a shallow cut. Feed the shelf on end into the bit, keeping it flush against the fence with one hand while pushing it forward with the other hand (left). Test – fit the cut end in a half-dovetail dado. Adjust the fit, if necessary, by moving the fence Me inch away from the bit and making another pass. Repeat the cut at the other end of the shelf.