AW Extra 12/26/13 – Adirondack Loveseat
It’s just as comfortable as it looks.
By Tom Caspar
*About This Project: Our Adirondack two-seater is based on one built by Jack Priest as a centerpiece for the deck outside his son’s restaurant, The Tin Fish, overlooking Lake Calhoun, in Minneapolis, Minnesota. Our design is slightly different from his. We’ve changed the arms and their supports a bit, as well as the back’s profile, but that’s what Adirondacks are all about. Once you’ve got the basic structure down, it’s easy to customize an Adirondack any way you want. Adirondack chairs represent all that’s best about American design: they’re practical, with no unnecessary parts; they’re accessible, because just about anyone who can cut wood can make one; and they’re perfectly suited to their setting, the great outdoors.
An Adirondack’s low seat and broad arms invite you to slow down and take it easy. Most Adirondacks are single chairs, of course. A two-seater is something special. Sharing the Adirondack experience with a friend makes it all the better.
Materials and tools
This project is built from western red cedar construction lumber, which is commonly available at home centers and lumberyards. You’ll need two 2×6 boards, 8 ft. long, and nine pieces of 5/4 lumber–1 in. thick, 5-1/2 in. wide and 12 ft. long. Dust from cutting western red cedar can be irritating, so wear an appropriate dust mask and work in a well-ventilated shop or outdoors. Use rust-resistant deck screws to assemble the project. You’ll need about 100 1-1/2-in. screws and 50 1-1/4-in. screws. You’ll also need two inside-corner braces and 100 screw-hole plugs (see Sources, below).
You’ll use a tablesaw, bandsaw (or jigsaw), router table, 3/8-in. roundover bit, 30- degree chamfer bit, cordless drill and a file for the project. A miter saw is also handy.
Make the legs and seat
1. The love seat sits on three back legs: two on the sides (A1, Fig. A, below) and one in the center (A2). They’re virtually identical, except for one important detail: the notch for the lower back rail (A5) is positioned farther back on the center leg than on the outer legs (Fig. H). To ensure that all the legs come out the same, make one paper pattern based on the measurements given for the outer back leg (A1). Trace around the pattern on three leg blanks cut to the same length, omitting the notches. Then draw the notches directly on the legs. In addition, set your miter saw to 18 degrees and cut a miter on a scrap piece of 1×6. Use this piece to draw the angled lines that indicate the location of the front legs. Draw these lines on both sides of each outer leg.
2. Saw the legs (Photo 1). Smooth the saw cuts with a file or 80-grit sandpaperwrapped around a block.
3. Make the seat slats (A3). Discard pieces with large knots—they’ll weaken the slats. Drill holes for screws and plugs in the ends and middle of all the slats using a 3/8- in.-dia. combination countersink/counterbore bit (Photo 2). Make the plug holes about 1/4-in. deep. Round the top edges of the slats, and all other exposed edges as you build the project, using a 3/8-in. roundover bit mounted in a router table.
4. Line up the front edges of all three legs. Temporarily fasten a slat to the middle of each leg. Glue and screw the first four slats (Photo 3).
5. Make the two pieces that comprise each front leg (B1 and B2) from one long board. Rip the board to remove its rounded edges. This makes a better-looking joint when you glue the pieces together. Cut one end of the blank at 18 degrees, then cut the inner leg to exact length (Fig. E). Cut the outer leg to length, then glue and screw together the leg pieces (Photo 4). Note that the two front legs are mirror images of each other.
6. Apply glue to the front legs and clamp them to the back legs. Use the lines you drew in Step 1 to position the front legs. Drill holes in the front legs for screws and plugs, then run in the screws (Photo 5).
7. Make the back seat slat (A4, Fig. F) and lower back rail (A5, Fig. G). Note that the inside curve on each end of the lower back rail consists of three flat sections, to receive three back slats. The straighter these sections are, the stronger your joints will be. After sawing, use a file to straighten these cuts, if necessary. Use a file to flatten the rail’s center straight section, too. Drill holes for screws and plugs in the back seat slat and lower back rail, then round over the edges of both parts with a 3/8-in. router bit. Don’t round over the inner edge of the lower back rail, where the back slats (D1, D2) go.
8. Remove the seat slat you temporarily screwed to the back legs. Glue and screw the lower back rail in position. Screw the back seat slat next to it, but don’t glue it. Add the rest of the seat slats. Space them about 1/4- in. apart. Temporarily clamping some slats in position makes it easier to space them.
9. Remove the back seat slat.
Add the arm assembly
10. Rip two 5/4 pieces for each arm (C1) and glue them together (Photo 6). Cut each blank to length, then saw out the curves (Fig. J). Sand the glue joint, then round over both sides of the arm with a 1/4-in. roundover bit. Don’t round the curved section where the arm overlays the back rail.
11. Make the upper back rail (C2). This piece has three straight sections on either side (Fig. M), like the lower back rail. Trace the curves of the arm pieces on the ends of the rail. Cut out the rail using a bandsaw, with the table set at 90 degrees, and straighten the flat sections with a file. Rout a 30- degree bevel on the inside edge of the rail (Photo 7). Leave a 1/8-in.-thick blunt edge to guide the bit’s bearing.
12. Glue and screw the arms to the upper back rail. Note that the inside edge of each arm is square to the back rail (Fig. C), and that the screws go from underneath the back rail and into the arms (Fig. A).
13. Cut two temporary support pieces (C3) to hold and level the arm assembly. Prop the assembly on these pieces and the front legs (Photo 8). Once the assembly is correctly positioned front-to-back and side-to-side (Fig. D), clamp it to the front legs, so it can’t shift.
Fit the back slats
14. Make a set of back slats (D1 and D2). You can rough-cut two slats from one 5-1/2-in. wide 5/4 board using a bandsaw. Build a tapering jig and cut each slat using the tablesaw (Photo 9 and Fig. K). The exact angles on the slat’s ends are not important.
15. Drill screw-and-plug holes in the lower ends of the outer slats (D1). Mark the positions of these slats on the lower back rail (Fig. B). Clamp the slats in position (the top ends of the centermost slats touch each other) and mark locations for the screws that will go into the upper back rail. Remove the slats, drill the screw-and-plug holes, then attach–but don’t glue–the slats in place (Photo 10).
16. Install one of the inner back slats (D2) midway between the outer back slats. It should be vertical. Fit the remaining slats (Photo 11). Make the gap between them about 1/4-in. After these slats are fitted, mark their screw-and-plug holes and cut off any excess length at the bottom. Then install the slats with screws, but don’t use glue. Repeat this process on the other side of the back.
17. Make a trammel and find the center point of each half of the back (Fig. L). Turn the trammel around and draw each curve (Photo 12).
18. Mark the position of all slats and remove them. Bandsaw their top ends and round over all their edges. Glue and screw the slats back in place. Cut a piece of paper to fit the gap between the two back sections. Fold the paper in half and use it as a pattern to make two pieces (D3) to fill the gap. Install these pieces.
Support the arms
19. Connect the arms and legs with inside corner braces (Fig. A). Use #10 or #12 pan head screws to install them.
20. Cut two corbel blanks (B3). Rout stopped grooves on the inside edge of each blank to accommodate the corner brace and screw heads (Photo 13). Saw the corbel’s shape (Fig. N) and round over its outside edges. Make sure each corbel’s top fits tight under the arm. Drill screw-and-plug holes through the front legs and screw and glue the corbels to the front legs (Photo 14).
21. Install the back seat slat. Glue plugs in all the screw holes. Cut and sand them flush.
22. Apply two coats of exterior oil finish. It’s best to do this outside, for good ventilation. Sit and enjoy!
Fig. A: Exploded View
Fig. B: Slat Location
Fig. C: Arm and Back Rail Assembly
Fig. D: Cross Section
Fig. E: Front Leg
Fig. F: Back Seat Slat
Fig. G: Lower Back Rail
Fig. H: Back Legs
Fig. J: Arm
Fig. K: Back Slats and Tapering Sled
Fig. L: Drawing the Back’s Curve
Fig. M: Upper Back Rail
Fig. N: Corbel
1. Begin building the love seat by sawing out the back legs from a western red cedar 2×6. You’ll get the most accurate cuts by using a bandsaw, but you could use a jigsaw, instead.
2. Joinery is simple: just screws and glue. You’ll cover every screw hole with a plug later on. As you build the love seat, drill holes for the plugs and screws simultaneously with a combination bit.
3. Assemble the seat. Fasten the first four seat slats, which are made from 5/4 cedar boards. Check for square as you go. Temporarily add a slat to space the legs the correct distance.
4. Screw and glue together the front legs. Use a water-resistant glue to assemble all the parts of the project.
5. Glue and screw the front legs to the seat assembly. Then add the rest of the seat slats and the lower back rail, which sits in the notches on the back legs. Assembly is much easier if you work on a large, flat surface, such as a door.
6. Glue the arms together from two pieces of 5/4 material. To make a tight, invisible joint, first remove the rounded edges of this construction lumber by ripping the boards on the tablesaw.
7. Rout a 30- degree bevel on the upper back rail using a router table. The love seat’s back slats lean against this piece; with an accurately made bevel, you’ll get tight, strong joints.
8. Add the arm and upper back rail assembly. Stand it on two supports and adjust its position until the bevel you routed is in line with the lower back rail. Check this with a straightedge.
9. Taper the back slats using a jig for your tablesaw. Mount toggle clamps on the jig to keep your fingers away from the blade.
10. Spacing the love seat’s back slats requires careful measuring and marking. Begin by temporarily installing the four slats that define the two halves of the back.
11. Fasten the middle slats next. Then install two slats between the middle and outer slats. Adjust these slats up or down to make the spacing even.
12. Draw a curve across the back using a shopmade trammel. That’s just a stick with a nail at one end and a pencil stuck in a hole on the other end. Remove the slats and cut the curve on each piece.
13. Rout grooves on the ends and inner edges of the corbels, the wing-shaped pieces that support the love seat’s broad arms. These grooves hide metal braces under the arms.
14. Fasten the corbels to the legs with glue and screws. The brace allows you to safely lift the love seat by its arms.
15. Once every part is in place, glue plugs in each screw hole. Cut the excess with a flush-cutting saw.
Note: Product availability and prices are subject to change.
Hamilton Marine, hamiltonmarine.com, 800-639-2715, 3/8” Dia. Bung Cedar (plugs), #FSW-05- C.
Rockler, rockler.com, 800-279-4441, 30- degree Chamfer router bit, #24805.
This story originally appeared in American Woodworker May 2008, issue #135.