When building a large solid-wood panel, such as a tabletop, you might be tempted to cap the ugly end grain by simply gluing another board across the end. Don't. The problem: Seasonal wood movement will cause that panel to cup at best, and self-destruct at worst, because the panel and cap expand and contract at different rates. The solution: breadboard ends that hide the end grain without hindering wood movement across the panel.
Here's how to plan a panel with bread-board ends.
- When you figure the overall finished length of the panel, take the breadboard ends into account.
- The breadboard ends are usually 2" to 3" wide, but you can make them wider or narrower for larger or smaller panels, if you wish. In either case, make the mortise depth about two-thirds the width of the end piece.
- Cut the tongue on the panel about [fraction "1" "4"]" narrower than the length of the mortise in the end piece, and drill the dowel holes through the approximate middle of the tongue length.
- The length of the breadboard ends equals the width of the panel at its widest, which occurs during high-humidity months. If you build the panel in the winter, when the air is relatively dry, make the ends a little longer than the width of the panel.
Follow the steps on the following pages to add this classic -- and functional -- finishing touch to your glued-up panel.
Mortise the end pieces
Center a [fraction "1" "4"]" mortise 2 [fraction "1" "8"]" deep on one edge of each end piece, stopped [fraction "3" "4"]" from each end. Drill both ends of the mortise first. Then, drill evenly spaced holes between the ends.
Clean out the mortises
Drill overlapping holes to complete the mortise, starting at the ends. Then, chisel the ends and sides smooth and straight and square the corners.
Cut the tongue cheeks
Center a [fraction "1" "4"]" tongue 2" long on each end of the panel. Set the tablesaw fence 2" from the outside of a [fraction "3" "4"]" dado stack, and make several passes with the saw adjusted to cut [fraction "1" "4"]" deep.
Saw the shoulders
Lay out and cut the shoulders to make the tongue width [fraction "1" "4"]" less than the mortise length. A guide block keeps the saw square and prevents marring the panel end.
Drill dowel holes
Dry-assemble the end pieces, centering them on the panel width. Along a line 1" from the joint, drill [fraction "1" "4"]" holes [fraction "5" "8"]" deep at the middle and 2 [fraction "3" "4"]" from each end.
Make slots in the tongue
Remove the end pieces, and drill [fraction "1" "4"]" holes on both sides of each end hole on the tongue to form [fraction "3" "4"] x [fraction "1" "4"]" slots. Straighten the slot sides. Replace the ends, and sand the joint flush.
Attach the ends
Form a [fraction "1" "16"]" bevel on all edges of the top and ends. Glue the middle one-third of the tongue. Drive in the dowels, gluing the end ones at the top. Cut and sand them flush.