ike the bottom, the top of a frame – and-panel cabinet is made from the same stock as the rest of the piece, usually individual boards edge-glued together. To determine the size, measure the frame and add the width of any molding you plan to install under the lip. Also take into consideration a small amount of overhang at the front and sides. Unless the cabinet will be featured in the middle
of a room, make the top panel flush with the back of the case.
Four common methods of attaching tops are illustrated below. One technique features rabbeted blocks, called “buttons,” which fit into a groove cut around the top rails. Metal fasteners can be used in the same way. Ledger strips, such as those used to attach a bottom panel to the cabinet, will work equally well for
securing a top. Another method calls for the creation of pocket holes in the rails before the case is glued up.
Whatever approach you choose, allow some play in anticipation of wood movement; otherwise, the top will buckle, warp and force the frame apart. Also, remember to install any drawer-hanging hardware (page 92) before putting the top on the cabinet.
Cutting a groove in the top rails
Fit a router with a three-wing slotting cutter and set the tool’s cutting depth for about % inch. Protecting the surface of the cabinet with wood pads, use bar clamps to hold a guide board flush along the edge on which the router will be riding; this will provide a surface to brace the tool as you cut the groove. For each rail, guide the router along the top edge, moving from left to right (left). Reposition the edge guide before cutting subsequent sides of the cabinet.
Set the cabinet top face down on a work surface, and position the case upside down on top of it. Align the back of the cabinet with the back edge of the top and center the case between its sides. Fit the rabbeted ends of three buttons into the groove in the rail at the back of the cabinet, positioning one in the middle and the other two near the ends. Leave a Уіб-inch gap between the lipped ends of the buttons and the bottom of the groove to allow for movement of the wood. Drive screws with a drill to fasten the buttons in place (left).
4 Squaring the top
Install a bar clamp across the front of the case, aligning the bar with the front rail. Using wood pads to focus pressure on the corners, butt one jaw of the clamp on the edge of the top and the other jaw on the front stile. To test for square, measure the gap between the edge of the cabinet and the edge of the top at several points on both sides. The gap should be uniform. If it is not, tighten the clamp (right) until the top is correctly positioned on the case. Install the remaining buttons (page 65), at least three per side. The buttons on the sides should be firmly seated in the groove; the buttons on the front—like those on the back—should be backed off slightly from the bottom of the groove.
Boring holes with a commercial jig
Use a drill to bore holes in two steps with two different brad-point bits: one slightly larger than the diameter of the screw heads, so they can be recessed, and one a little larger than the screw shanks to allow a little movement. Clamp a stop block to a work surface, then fit the first bit on the drill. Wrap a strip of masking tape around the bit to mark the drilling depth. Butt the top edge of an upper rail for the cabinet against the stop block, inside surface up, and clamp a commercial pocket hole jig close to one end. Holding the rail firmly, bore the hole, stopping when the strip of tape touches the jig. Reposition the jig to bore another hole at the middle (left) and a third one near the other end. Fit the second bit on the drill and bore the clearance holes in the same manner.
2 Attaching the top
Once the cabinet has been glued up (page 59), set the top face down on a work surface, and position the case upside down on it as you would when installing wood buttons (page 65). Fit a drill with a screwdriver bit and drive screws to attach the back rail of the cabinet to the top (left). Square the cabinet top the same way you would when installing wood buttons (page 66), then drive screws through the remaining rails.
Use a pocket hole jig, shop-built from 3/4-inch plywood, to bore pocket holes on a drill press. Refer to the illustration at left for suggested dimensions. For the jig, screw together the two sides of the cradle to form an L. Cut a 90° wedge from each support bracket so that the wide side of the cradle is angled about 15° from the vertical when it sits in the brackets. Screw the brackets to the jig base and glue the cradle to the brackets.
To use the jig, seat the pieces to be drilled in the cradle with their inside surfaces facing out and their top edges in the V of the cradle. Bore the holes in two steps with two different bits as described in step 1, page 66. In this case, use a Forstner bit and a brad-point bit.
With the brad-point bit in the chuck, position the jig on the drill press table so that the bit will exit in the center of the top edge of the rail. Clamp the jig to the table and install the Forstner bit in the chuck.
Holding the workpiece firmly in the jig, feed the bit slowly to bore three holes into the rail just deep enough to recess the screw heads. Then, install the brad-point bit in the chuck and bore through the workpiece to complete the pocket holes (left, bottom).