The tapers and contours on the Adirondack chair frame give it a refined appearance, while its low profile is designed for comfort. When building this chair, use Western Red Cedar, sanded on both sides. Standard 1x cedar stock will be used for all the parts with the exception of the upper backrest support which is cut from 5/4β cedar planed to 1 1/8β in thickness.
The tools needed for this project include a bench top table saw, a bandsaw, a power mitre saw, a drill press, a taper jig, a finishing sander and a stationary disc sander. Also needed are a cordless drill with driver attachment, a 1β diameter sander attachment for drill, c-clamps with pads, a straightedge, a framing square and a combination square.
To shape the back slats, cut three pieces of 1x cedar, 5 x 30β, and two pieces, 5 x 26β. Plot out a 1β square grid pattern on two 30β pieces and a 26β piece. Draw a middle slat and an inside slate on a 30β piece then draw an outside slat on a 26β piece. Use a table saw and a taper-cutting jig to cut the straight taper cuts. Identical taper cuts are then done on the inside slat and outside slat on the remaining unmarked workpieces. A second workpiece is ganged, or the edges are aligned and 1β arcs are driven at each corner, below the inside slat and the outside slat so that both parts can be shaped at the same time. Now use a power mitre saw to trim off the bottoms of the inside slats and the outside slats at an angle. Sand all edges.
Armrests are made by cutting two pieces of 1x cedar 8 x 28β. Plot out a 1β square grid pattern on the face of one piece. Draw cutting lines for the armrest on the grid then use a compass to draw the curves. Gang the workpieces together, and cut the pieces to shape using a bandsaw. Plane the cuts up to the cutting lines. Next cut the contours to rough shape then finish cut them. Sand all edges.
The upper backrest supports are made by cutting a piece of 5/4β cedar, 5 x 29β. Cut one long edge of the workpiece by setting the table saw blade to 20i bevel. Mark 3 5/8β from each end of the beveled edge. Use these marks as endpoints, and then draw an arc with a 51 23/32β radius. The top of the arc should be 1 5/32β from the edge. Cut the using a bandsaw set with a 20i bevel. Mark points 4 ΒΌβ from the high end of the bevel and draw a straight cutting line. Reset the table saw blade to 90i and square cut this edge. Using the outside corner of one armrest as a template, trace the upper corner profiles on the ends of the workpiece at the unbeveled edge, then cut with the bandsaw, checking them against the outside corners of the armrest. Sand all edges.
Lower backrest supports are made by cutting a piece of 1x cedar to 3 x 21 Β½β, then mark points 13/16β from each end along one edge. Using the points as endpoints, draw an arc with a 50β radius. Arc should be 1β from the edge. Cut with the bandsaw. This arc is square cut, not beveled as the others have been.
The arm rests and upper backrest supports are joined by positioning the upper backrest support on top of the armrest, so that the armrestβs outside corners are flush with the roundovers of the support and all edges line up. Drill three 5/16β pilot holes with 11/16β shank holes through each armrest and backrest support. Separate the parts and drill countersink and shank holes for #8 deck screws into the face of each armrest. Apply exterior wood glue to the matching faces of the armrests and upper backrest support. Make sure the pilot holes line up, then drive #8 x 1 Β½β galvanized deck screws through the armrest and into the support.
To make the armrest supports, cut two pieces of 1x cedar, 4x6β. Make sure the wood grain runs lengthwise on each piece. A 1β square grid is drawn on one workpiece and the armrest support pattern is transferred to it. Gang the two workpieces together, cut out the pattern with a bandsaw or scroll saw. Sand the pieces.
Making the legs begins by cutting two pieces of 1x cedar, 7 x 40β for the back legs. Now draw a 1β square grid on one workpiece and then draw the shape of the back leg layout on the grid. Use a compass and a protractor to check the accuracy of the curves. Gang the two workpieces together and cut out the shape using a bandsaw. Sand the edges. To make the front legs, cut two pieces of 1x cedar, 6 x 19 Β½β. Draw and cut a 1β radius roundover at the bottom corners of each leg then sand.
To attach the armrest supports to the front legs measure in 3β from the side of each front leg, at the top and bottom and mark a centerline parallel to the sides. Drill pilot holes through each centerline, 2β and 4β down form the top or square edge. Now place the armrests on the centerline, even with the tops of the front legs. Extend the pilot holes into the long edge of each armrest support. Drill countersink and shank holes at the pilot hole locations on the inside face of each front leg. Apply exterior glue to the matching surfaces then drive two #8 x 2β deck screws through each front leg and into the armrest support.
To attach the lower back support to the back legs place the lower back support on the back legs at the square notches on the top of each leg. The ends of the support are to be flush with the outside faces of the back legs. This establishes the width of the chair. Now attach the lower back rest support to the back legs using exterior glue and two #8 x 1 Β½β deck screws driven through countersunk pilot holes at the end of each support.
The seat slats are made by cutting 13 slats 21 Β½β in length from the cedar 1 x 2 and round the top edges with a sander or router. Use a drill press and drill a countersink pilot hole 3/8β from each both ends of each slat and centered from each side. Tack a slat to the top of the back legs, flushing the outside faces of the back legs with the ends of the slats. Test fit the seat slats, beginning with the back slat. The back slat should sit just over ΒΎβ out from the lower backrest support. Once the slats are positioned, attach them to the back legs using exterior glue and one #8 x 1 Β½β deck screw driven through each countersunk pilot hole and into the top edge of the back leg below.
Attach the back legs and front legs by using a C-clamp to secure the front legs in position against the outside faces of the back legs. Adjust the position of each front leg until the lower, front tip of the matching back leg is exactly 11 ΒΎβ above the worksurface and 2 ΒΌβ away from the edge of the front leg. Three pilot holes are drilled through the inside face of each back leg and into the front leg. Drill countersink shank holes into the back legs. Remove the clamps and apply exterior glue to matching surfaces of both the front and back legs. Clamp the legs back together with pilot holes aligned. Secure the joints with #6 x 1 ΒΌβ deck screws.
To attach the armrests to the front legs, cut a piece of scrap wood, 18 3/8β long for a temporary brace for the upper backrest support. Place the brace under the upper backrest support and set the armrests on the top edges of the front legs and armrest supports. The armrests should overhang the front edges of the front legs by 2 5/16β. Center the armrests side to side on the front legs. The distance between the bottoms of the armrests is 19 Β½β at the front and back of each armrest. Adjust the armrests if needed. Carefully lift the armrests and apply exterior glue to the tops of the front legs and the armrest supports. Reposition the armrests, drill countersunk pilot holes through the tops of the armrests and into the front legs and armrest supports. Drive #8 x 2β deck screws to secure the joints.
To begin attaching the back slats, the spacing between the slats should be determined and then tack the slats. Mark the contours as if the back slats were a single workpiece. A scrap piece of wood cut 20β long and clamped to the underside of the lower backrest support covers the gap between the support and the first seat slat. The back slat is then set onto the scrap wood cleat with the bottom of the back slats resting cleanly. The angled bottoms of the inside slats and the outside slats should be in the correct position. Now draw and cut out a 1β square grid pattern and the layout pattern of the back slats on a large piece of paper. Hold the back slats firmly in position and attach the pattern to the slats, then trace the cutting line across the tops of the back slats. Now mark the positions of the upper and lower backrest supports on the front faces of the back slats and mark the position of the slats onto the backrest supports. Remove the slats and cut out the contours of the top of the slats using a bandsaw. Sand the tops. Drill two countersunk pilot holes into the face of each slat, lining up the holes with the backrest supports.
To finish the chair, sand all surfaces to 180 grit and apply a finish, either a wood sealer, a stain or paint.
