Making the Back and Seat Supports

To minimize waste, lay out all of the back and seat supports on the same piece of lumber. With a combination square, mark the ends of each support. Rip and then crosscut on your table saw to separate the pieces from each other. You'll cut the pieces to shape later.

Lay out the half-lap joints as shown in the Overview Diagram. Install a dado head on your table saw, and set the cutting height to one-half the stock thickness. Angle the miter gauge at 25 degrees. Brace the stock against the gauge, and cut the joints.

Check that the pairs of seat and back supports fit flush by dry-clamping them together. Protect the stock from clamp marks with small pieces of scrap wood. When you're satisfied with the fit, spread water-resistant glue on the joining parts, and then clamp the pieces together.

Once the glue cures, remove the clamps, tape on the template, and trace the pattern onto the wood. Lay out two dowel holes in the center of the support, each about 1 inch from the edge of the joint. Mark the dowel centerpoints with an awl. Mark the notch in the seat support for the cross support.

Using a 1/2-inch bit, drill holes at the awl marks. Cut six 1 1/8-inch lengths of 1/2-inch dowels. Reinforce the lap joints by gluing the dowels into the holes. Sand the surfaces smooth.

Bore a 3/8-inch hole at the mark shown near the front edge on the inside face of the two outside supports. Use a combination countersink bit that lets you drill counterbore, clearance, and pilot holes at the same time.

Cut all three seat assemblies to shape with a saber saw. Clamp them together, and sand their edges with a belt or drum sander.

Cut the cross support to size and shape. Mark the three notches as shown on the template. Also mark the bolt positions. For each one, counterbore a 7/8-inch hole 3/4 inch deep, and drill a 5/16-inch pilot hole through the center.

Put a dado head on your table saw, and set the cutting height to 1 inch. Butt the cross support against the miter gauge. Cut the three dadoes in the cross support, guiding the cuts with the miter gauge. Place a scrap block behind the piece to prevent "tearout" at the notch.