here are several ways to install a bottom on a frame-and-panel case. One method that is popular among cabinetmakers calls for grooves along the inside faces of the bottom rails and the stiles prior to gluing up the individual frame- and-panel assemblies. The grooves can be made with a dado head on the table saw, and they should fall about 1 inch from
the top edge of the bottom rails. They should be about Vi inch wide and half as deep as the thickness of the stock; stop the groove in the stiles at the point where the side rails butt up against them. To install the panel, narrow its edges slightly with a plane, allowing the piece to fit snugly in the grooves, but not completely restricting its movement.
Another type of installation, shown below, relies on ledger strips, which are screwed to the bottom rails. With this approach, the bottom can be installed after glue up. Using either method, the bottom is made from the same stock used for the rest of the case. Make the width of the panel slightly narrower than its opening to allow for wood expansion.
Saw four 1-inch-square ledger strips to fit along the rails at the bottom of the cabinet, cutting them slightly short to make them easier to install. Bore two sets of holes in each strip: one in the center along one edge, for screwing the strip to the case, and another to the side of an adjacent edge for attaching the bottom panel. Bore the holes in two steps with two different brad – point bits: one bit slightly larger than the diameter of the screw heads for recessing the fasteners and another bit slightly larger than the diameter of the screw shanks to provide clearance
holes. (The wider hole will allow for movement.) Position the strips on the inside surface of a rail about 1 inch from its top edge and mark the positions of the screw holes with an awl. Bore a pilot hole for a No. 8 screw at each marked point, then use a drill fitted with a screwdriver bit to fasten the strips to the case (above, left). To install the bottom panel, set the case on its back. Holding the panel flush against the strips with one hand, screw the bottom panel in place (above, right).