Base molding is often added to a bookcase to “anchor” the piece and complement any crown molding installed at the top. There are two basic ways to build a base. The first is to make a rabbeted mitered frame of molded pieces from stock standing on edge (see below); this frame wraps around the base of the bookcase like a skirt and hides the joinery at the bottom of the carcase. The second method involves building a mitered frame of horizontal molded stock; this provides a flat surface for attaching turned feet (page 58). Both methods allow for wood expansion and can also be adapted to fit modular bookcases or bookcases joined together.
Assembling the frame
The frame shown above is made from three pieces of molded stock, a back, and four corner braces. A rabbet is cut along the inside edge of the molded pieces, forming a lip that the book case will sit on. To make the base molding, first prepare three pieces of solid stock and rout a decorative molding in the edge
2 Installing the base molding
Once you have finished assembling the frame, attach the unit to the bottom of the bookcase. To reinforce the joint, screw two angle brackets midway along the inside frame of the base molding. Spread glue on the rabbet on the front piece of the frame and on the first inch of the side pieces. (This will cause any wood movement to take place toward the back of the carcase, preventing the miter joints at the front from breaking.) Then set the frame in place on the bookcase, and screw the brackets to the bottom of the carcase.
If your bookshelf features no base molding and a fixed shelf is located near the bottom of the piece in place of a carcase bottom, you can install a bottom brace to hide the space below the shelf (above, left). Simply cut the brace to size and glue or nail it in place from the ends and the top of the bottom shelf. You can also cut a decorative pattern in the brace (dotted lines). A base molding (above, center) glued or screwed to the front and sides from inside the carcase is another option. You might also choose to attach ogee bracketed feet (above, right). (See page 97 for more information on their construction and installation.)
Routing decorative details
If you are building a bookcase that features both bas and crown molding, you can use these adornments as convenient stop blocks for routing a decorative chamfer or other detail in the sides of the face frames. Install a piloted decorative bit in your router. With the bit clear of the
work, butt the tool’s base plate against the crown molding. Turn on the router and ease the bit into the work. Continue cutting until the base plate touches the molding at the opposite end.
2 Installing the feet
Once you have turned all the feet, screw them to the bottom of the base molding. Unlike the vertical base molding shown on page 56, the base illustrated at left is horizontal, with a wide rabbet routed in the face of each piece that accepts the bottom of the bookcase; a molding is cut on the frame’s outer edge (page 96). After assembling the base, drill a countersunk hole three-quarters of the way through the center of each foot, then bore a pilot hole the rest of the way through the wood. Screw the feet to the base (left).
If you are building more than one bookcase or a modular wall unit, consider attaching adjacent bookcases together for stability. A quick and efficient way to do the job is to use threaded connectors to join adjacent sides (above). With the two bookcases side by side and properly aligned with each other, bore a hole through the two side panels. Install a threaded connector; for stability, use four to six connectors along the length of the side panels. If your bookcases have face frames, you can install intermediate stiles to hide the gap between the two bookcases.