Making a dovetailed table

The author's side table in New Guinea rosewood

Words and photos: David Luckensmeyer
Illustration: Graham Sands

When I received a request to make a side table for home, I knew I wanted to tackle sliding dovetails again. They offer an elegant joinery method that keeps solid timber braced and flat. Let me show you how to make them on the tablesaw.

I also cover how to make tapered under-bevels. Large cantilevers add quite a visual element to the table. Along the way I share a few design tips for a project like this.

Design considerations

The budget is tight so a straightforward design is important. There are really only two constraints: the table must fit against a 1500mm long wall, and it must have a lower shelf for storage. I just don’t have time to consider curves, laminations, doors or drawers.

My side table has a top, two legs and a shelf. I began with the nominal length restriction and a common height range of 600–900mm. The overall dimensions offer a nod to the golden ratio (5:8 is a close approximation), while specific decisions – overhang length, width, shelf position – are proportional to the table’s length. Even the square negative space is pleasing (fig.1).

Prepare the material any way you like, gluing for width, and then aiming for the dimensions in the cutting list.
Or whatever suits your needs. Sand faces now as sanding later yields loose joints. Edges can wait (photo 1).

The leg length must account for the material thickness (30mm) and joinery (20mm) to achieve an overall height of 850mm (e.g. 850- 30+20=840). Likewise, the length of the shelf depends on the position of the legs, less the material thickness, plus the sliding dovetails on both sides (e.g. 680-30+40=690, photo 2).

Sliding dovetails

There are two sets of sliding dovetails in this table. The leg-to-top connection is made using a combination of a router and a tablesaw jig. The shelf-to-leg connection is made entirely on the tablesaw with the jig.

Why use a tablesaw to make sliding dovetails? For safety and adjustability of fit. The material is clamped safely, and the machining process is repeatable and easy.

The jig is basically a box, wide enough to hold the workpiece, and deep enough to provide rock-solid stability. As a reference, my jig is 500 x 250 x 250mm high (photos 3, 4).

Machining part A

Tablesaw arbors that tilt one way (i.e. most saws including mine) can only make the half-version of part A unless your joinery is central and you can turn the part 180°. Consequently, I used the half-version for the shelf-to-leg connection. For the leg-to-top connection I wanted a more traditional look, so I used a conventional router and dovetail bit for the trench.

Step 1: Make a trench using a mitre gauge, crosscut sled or in my case the crosscut fence on my sliding tablesaw, and a flat-bottomed blade. This step works for both versions (photo 5).

Step 2: The half-version is made by tilting the blade to achieve the triangular ‘dovetail’ shape on one side (photos 6, 7).

The traditional version is achieved by clamping a temporary fence to the project and using a router (photos 8, 9).

I like to size sliding dovetails at no more than two-thirds of the material thickness. In this instance, the material is 30mm so my dovetails are 20mm deep.

Machining part B

The tablesaw jig makes adjusting the fit of sliding dovetails a breeze, and  works equally well for both versions. The only difference is whether the timber is passed through the saw on one or both sides.

Step 1: Establish the shoulder of the dovetail using the same blade for trenching earlier. Cut the shoulder on one (half-version) or both sides (traditional version; photo 10).

Step 2: With the blade tilted at the same angle as before (here 7°), clamp the workpiece in the jig and set the rip fence for a shallow first pass. Your tablesaw should be free of dust so jig and workpiece register accurately (photo 11).

The half-version requires a dovetail  cut on one face, while the traditional version requires machining on both faces (photo 12).

The final fit is obtained by making very small adjustments to the rip fence, and running the package through the saw again (photo 13).

Tapered under-bevels

An under-bevel provides an easy way to add character to a simple piece of furniture. It also lightens the look of the top. The size of the bevel is up to you. Stronger tapers (e.g. from 30 to 5mm) bring a radically modern element to the design.

I settled on a taper from 30 to 15mm. Long under-bevels mean less usable space for the lower shelf. I considered proportions of 3, 4 and 5, and settled on an overhang equal to a quarter of the length (1360÷4=340). There is no right or wrong here (photo 14).

Step 1: After the tapers are marked, use a power planer or hand plane to remove most of the material. Work from both sides to eliminate tear-out.

Step 2: Use a block plane to chamfer the edges to the tapered line (photo 15).

Step 3: Now use a smoothing plane to form the taper. There is no need to check your progress as the diminishing bevels indicate where to remove more material. Alter plane strokes from across the grain and on the angle. Finish with passes along the grain (photo 16).

Building and design tips

Even if you don’t like the look of half- version sliding dovetails, the tablesaw jig is still worth making. Part A can be made any way you like (blade, dado, router, etc.), but use the jig to make part B safely and easily.

The tablesaw work described above calls for two blades. While the specially ground blade is nice, it is not strictly necessary. I have made hundreds of half-version sliding dovetails using a standard blade (photo 17).

Regardless of which blades you use, keep in mind that you should make the trenches (part A) and the shoulders (part B) first. Only then tilt the blade to your chosen angle. This ensures that both parts fit perfectly.

I would have loved to angle the legs by 2.5° so the legs meet the taper at right angles. Alas, such a design would have complicated the joinery. Doors and drawers would be welcome additions to this project. But they would need to be the subject of another article.

Assembly and finish

I like to pre-finish components where possible. I didn’t bother taping the joinery as sliding dovetails are easy to avoid while applying oil. Of course if you opt for a sprayed finish, you’ll need to mask off the joinery. I had planned to add a sparing amount of yellow glue to the joints. Since sliding dovetails are a mechanical joint, the glue serves only to keep components aligned.

But during the assembly, I found the sliding dovetails had tightened slightly as a result of the oiling process. A few firm taps with a wooden mallet aligned the components and I decided not to use any glue. I love knowing that this side table does not wobble or rock even a little, and yet can be disassembled at any time. If the joinery becomes loose in the future, I can always add a spot of glue then.

David Luckensmeyer @luckensmeyer is a Brisbane-based furniture designer maker, see www.luckensmeyer.com.au