This project is the second of three dining room projects. Last issue we built a large double pedestal dining room table. This issue we build the chairs that go with that table. Next issue, we’ll do a hutch to tie everything together.

This chair was designed to be both comfortable and sturdy. Like the dining table, my choice of red oak for the chairs is a personal preference; you can use a wood species that suits your taste and décor.

The chair is assembled using mortise and tenon joinery. There are, however, a couple construction steps that require a lot of attention and some skill (i.e. cutting the back leg assemblies and forming the mortises). Just don’t rush through the project; it’s really not all that complicated if you take it one step at a time. I didn’t show a materials list for this project because you can use a lot of cut-offs in your shop for chair construction.

In addition to construction details for the chair frame, I will be showing you how to upholster the seat using a flat panel, 2″ thick foam, and fabric. Of course final finishing, with oil based polyurethane (to match the dining table) should be completed before the upholstery phase.

Create a Template

Create a template using 1/4″ hardboard or plywood for the twelve leg/back assemblies. Follow the dimensions shown in the illustration. The critical reference for these assemblies is shown by the framing square placement. The surface of each leg that rests on the floor must be a 90º to the face where a chair rail will be connected.

Cut Legs and Back on Band Saw

Cut all the leg/backs (A) on a band saw. Follow the outside profile of the line, leaving the pencil marks visible to help guide in the sanding stage. Sand all the parts using a drum sander and a random orbital palm sander. The twelve leg/backs can be cut from four boards that are 1-1/4″ x 5-1/4″ x 96″.

Keep Flat Face Straight During Cutting

The lower edge of the chair side rail (E) will be 14-1/2″ above the floor. The 1/2″ thick mortise for that chair rail tenon begins 1/8″ above that mark. The ¾” deep mortise should be 1-7/8″ long and centered on the leg/back edge to accept the side rail tenon. Carefully cut these mortises in each leg/back using a dedicated mortiser, mortising attachment on your drill press, or by hand. Each mortise is at 90º to the leg/back flat face. I support one end with a block to keep the flat face running straight as I move the parts during the cutting steps. If your mortiser has a traveling side-to-side carriage, you’ll only have to set the flat surface level once.

Use Template to Locate Inside Mortise (Top and Centre)

The two upper and lower back rails (B) will be joined to the leg/backs (A) using mortise and tenon joinery. The mortises need to be accurately located. To accomplish this, place a mark 2″ down from the top and 1/4″ in from the front edge of your leg/back template. The next reference mark is placed 3/8 ” from the front edge and 14-1/4″ above the bottom edge of each leg/back. Draw a straight line between the two points. That line represents the angle on the front face of both rails (B). Trace the outline of each rail with a block of wood 1″ x 2-3/4″. The upper and lower points (previously marked) position the front bottom corner of the lower rail and top front corner of the upper rail. The front face of each rail should be aligned on the line that you marked between the two reference points. Next, draw an inner rectangle inside each back rail outline that’s 1/4″ inside all the lines. That rectangle represents the mortise outline, which should be 1/2″ x 2-1/4″. Cut out the mortise outline on your template and mark each leg/back. All these mortises are cut 3/4″ deep. Mark each pair of legs 1L, 1R, 2L, 2R and so on to identify the parts, as you will be forming a right and left side as you drill the mortises.

Cut Tenons With Stacked Dado Blade

At this point cut the twelve back rails to size, and machine the tenons on each end. The rails (B) are 16-1/2″ long, which includes a 3/4″ tenon on both ends. The tenons should be 1/2″ x 2-3/4″, centered on each rail end. They can be cut with a stacked dado blade that’s set 1/4″ above the table surface.

Fit Back Slats Onto Top and Bottom Back Rails

There are three back slats (C) which fit into the top and bottom back rails (B) for each chair. The slats require a 1/2″ x 3/4″ tenon that’s 1-1/4″ wide on each end. The three slats are equally divided across the rails with a 2-5/8″ space between them. The rails (B) need three mortises, centered on each rail, to receive the slat tenons.

Be sure to verify your measurements before cutting the slats to length. The distance between my (B) rails is 17-1/4″, which means my slats must be 18-3/4″, because of the 3/4″ tenon on each end.

However, slight positioning differences of the leg/back mortises or cutting of the leg/backs may change your slat rail length. That’s fine, as your chairs will probably be slightly different, but you must custom fit any part that spans two fixed points.

Mortise Leg/Backs for Chair Rungs

The final mortise in the leg/backs is required for the chair rungs (G). It’s located in the center of the front edge of each leg and is 3-1/4″ above the bottom as shown. This mortise is 1/2″ x 3/4″.

Round Over Front Top Edge of Upper Rails

Before beginning the round over process, finish sand all the chair parts that have been cut to this point. The first task will be to cut a 3/4″ radius, using a 3/4″ radius round over bit in your router table, on the front top edge of six upper rails (B).

Round Over All Chair Parts

All of the chair parts, including the ones not yet cut, (i.e. front legs, rungs, stretchers, and rails), should be rounded over on all the edges using a 1/4″ radius router bit. This easing of corners will remove the sharp edges, and “soften” the appearance of your chairs.

Assemble Leg/Backs on Back Rails with Slats Between Rails

Assemble the leg/backs (A) on the back rails (B) with the slats (C) in between the rails. Use glue on all mortise and tenon joints and check that the assembly is square. Clamp and set aside until the adhesive cures.

Cut and Mark Mortises

The front legs (D) are made using 1-5/8″ square stock. They each require three mortises. Cut and mark the mortises carefully, because you will be creating a right and left leg.

Cut Offset Tenon with Dado Blade

The side rails (E) are 3/4″ thick material with an overall length, including tenons, of 15-3/4″. Note this blind mortise and tenon joint requires an offset tenon on the front end of the side rail. The cheek cuts are 1/8″ deep to center the tenon, but the end cuts are different. You may also have to cut a small corner off the tenon that fits into the leg/back assembly to clear the back rail tenon.

Dry Fit Offset Tenon

The front rails (F) are cut to a total length of 15-3/4″, which includes the 3/4″ tenon on each end. Both ends require an offset tenon. The cheek cuts are 1/8″ deep to form a 1/2″ tenon. The end cuts are 1/8″ and 1″ deep to create the offset to fit the front legs. Dry fit all the parts. Your mortise and tenon joinery should fit snug but not too tight or too loose. Too tight and all the glue will be removed as the tenon is inserted. Too loose and the gap will not allow the adhesive to bind the parts. After assembly, verify the rung and stretcher dimensions, in case your leg/back is formed differently than mine.

Angle Fit Rung Tenons

The two rungs (G) for each chair require a little extra machine work on the tenons to achieve the angled fit on the leg/back end. I needed a 10º mitre on one end of my rungs but I suggest you verify the angle required for your chair because, as I mentioned, there will be slight differences depending on the cut and forming of the leg/backs. Set the mitre slide on your table saw at 10º to mitre one end of each rung. Then cut them to the required 17 -3/4″ length, measured from the long point of the mitre. Your table saw mitre slide should be set at 80º to make a 1/8″ cheek cut that’s 3/4″. The opposite cheek cut is made with the mitre slide set to 110º.

Cut Square Tenon on Band Saw

The two end cuts, which will form a 1/2″ square tenon, are completed on a band saw. Use your mitre slide and fence to first cut the ends to make a 1/2″ square tenon. Then, use the band saw mitre slide, set to the 80º and 110º positions, in combination with your fence to trim the waste. The opposite end of this rung requires a 1/2″ square tenon, centered on the end, to fit the front leg mortise. Also, all the rungs need a 1/2″ square mortise that’s 1/2″ deep in the center of the rung, at the center point of their length, for the stretcher boards.

Secure Stretchers Between Chair Rungs

The stretchers (H) run between the two lower chair rungs and are secured in two mortises that are 1/2″ square and 1/2″ deep. The stretchers require a 1/2″ square by 1/2″ long tenon on each end. Round over all the visible chair parts with a 1/4″ radius router bit and assemble the chairs with glue. Notice that the stretchers are installed flat with the wide face up.

Glue and Screw Corner Blocks

The front two mitred corner blocks (J) are attached with glue and screws.

The two back corner blocks (K) are cut with a 45º mitre on one side, and a compound 45º/10º mitre on the back, to fit the slanted lower back rail. Use 1-1/4″ screws and glue to attach these blocks.

Notch Seat Back

The seat platforms (L) are made using 1/2″ plywood. The back end requires two notches to fit between the leg/back boards. Once they’ve been cut to size, round over all the corners so they won’t damage your fabric.

Cut Foam

Cut a piece of 2″ foam that is 1/2″ greater than the length and width of the seat board. The foam will extend past all seat board edges by 1/4″. The foam can be cut with a utility knife and glued to the seat board with spray adhesive.

Attach Fabric

Cut your fabric 25″ square. Center the seat on the material and attach the front and back with a staple in the center. Next secure both sides of the material with a staple at the center point. Pull the material so it’s snug but not stretched.

Pull the four corners tight and temporarily staple them to the underside of the seat board.

Start at the center of each edge and pull the fabric tight as you staple and work towards each corner. Be sure the fabric is tight but not stretched. Complete all four edges making sure the pattern (if your fabric has a pattern) is straight and the material is snug. The staples should be 1″ apart.

Remove the temporary corner staples. Bring the side edge of your material, at each corner, tight and flat on the seat board. Staple this piece in place. Form the front edge of the material over the side material forming a pleat. Anchor the material well with staples. Repeat this step at each corner.

Add Upholstery Piping

As a final touch, an upholstery piping can be added to fill the gap between the seat and the chair. Staple the piping to the bottom of the seat on the front and two sides. After finishing the chairs, secure the upholstered seats to the frame using 1-1/4″ screws through the corner blocks.

Now, all you have to do is sit and relax on your new dining room chairs – you deserve it!

over side

In the next issue, we show you how to build the final piece for this series, a dining room buffet and hutch. It’s a little larger than the normal pieces found in furniture stores so you can store all your fine dishes and serving ware. And, as with last issue’s dining table, the hutch can be sized to suit your needs.

Tip - Clamp Before Sanding

Clamp the leg/backs in groups of 3-4 pieces for the initial sanding. Then, when all the pieces have been sanded, clamp all of them together for the final sanding and shaping. This technique will guarantee that all the pieces will be identical.