Garrett Hack's Demilune tables
Words: Garrett Hack
Studio photography: Bill Truslow
Process photos: Garrett Hack
Diagrams: Graham Sands
The elegance and curves of a demilune table lure me to design and build one often. It’s such a wonderful form even without any ornamentation, but I see each one as an opportunity to explore new details — inlays, beads, cuffs, and toes. There are challenges — making a laminated front apron and angled joinery — and while I can’t explain every step, I’ll cover some of my design process and construction. The photos show some of the demilunes I have made and in-progress shots of others.
Curves and joinery
Above: Demilune detail showing veneer matching on drawer front and mother-of-pearl handle inlay.
I design a demilune with an elliptical rather than circular shape. The half ellipse of the front apron and curve of the top are a more interesting shape than the static radius of a circle as they constantly change as you view the table from different angles. The more acute, rather than 90°, back corners of the top are also more dynamic. Sometimes I’ll inlay these back corners with black and white fans just to bring more attention there. And a slightly flattened ellipse is a pleasing proportion, much longer than it is deep.
My square legs taper along their entire length and on all four sides. I don’t actually taper all four sides, but cut twice the amount of taper off two adjacent sides — about 2° — so that when the centreline of the leg is vertical each side is at about 89° to the floor. This taper angle is an important angle, one I’ll use later to cut the slightly angled shoulders on all apron joints. My legs are quick to make and look clean, and have other advantages, as I will explain. Sometimes I shape a secondary taper on the toe of the foot, which gives the whole table lift and the delicacy of a ballerina.
My demilune might seem delicate, but the laminated curved apron is the secret to its strength and lightness. It joins into the rear legs with mortise and tenons and with a bridle joint for the front legs. Cutting the laminates, gluing and clamping them in place on the form, and then truing it up later takes time, but I know of no easier way to get a smoothly curved apron so thin and strong.
Work from the drawing
A full-scale top view drawing (fig.1) is a must to build this table. This is the place to work out the joinery, to see the actual shape of the curve, and most importantly how things connect and at what angles. I use it as a working drawing, laying the curved apron on it to mark the position of a joint or angles of the shoulders. I take the time to make an accurate drawing, complete with centreline and baseline parallel to the straight back apron, all of which helps to keep things symmetrical.
Allow for springback
One method of establishing the curve of the apron is by flexing a thin wood batten into a fair shape as long and deep a table as I desire (accounting for the overhang of the top as well). I trace this on a piece of heavy paper, fold it in half on the centreline, cut it out and true it up a bit so it’s symmetrical, and now I have a pattern to build my form. The only problem is, the lamination is going to spring back once off the form, or flatten about 5/16” (8mm) on either end, so I need to alter the pattern to a tighter curve. I’ll use the actual laminated apron to refine my drawing later.
The tenons on the apron are cut on the tablesaw with a tenoning jig. Double blades with spacers between them are used. Note the use of a support block to hold the curved apron at a right angle when cutting.
Rear leg to apron joins
The rear legs and aprons join with haunched mortise and tenons that ‘mitre’ inside the rear legs. For strength the tenons are nearly the full height of the aprons, with an angled haunch at the top and no shoulder at the bottom. My most important reference line I build to is the bottom of the mortises and aprons. No shoulder here maintains this accuracy. I can then plane a shaving off the bottom of each apron before glue-up so that I have a fresh surface for my cockbead, or precisely land a banding at this point around the entire table and leg (the dado for the banding cut earlier).
1. The rear leg mortises are cut on a slot mortiser, however the haunches are chiselled out by hand.
By far the trickiest part of building a demilune is dealing with the angled joinery, cutting well-fitting joints but also making a table that can go together. If the tenons on the curved apron angle outward too much — which is their strongest orientation — the apron is too stiff to compress enough to get the joints together with the back rail assembled. That would be an interesting problem to discover during glue-up!
2. The cut-out (haunch) on the apron tenon that joins to the rear leg adds strength by creating greater gluing surface area. Here the haunch needs to be angled.
Ideally I’d like the mortises square to the leg so the tenons, angled or not, will have square shoulders I can finetune with a shoulder plane. A simple design compromise between these too-angled tenons and square mortises is to rotate the rear legs 10° or so. It’s never even noticed, and yes the rear apron joinery is now no longer at 90°, but it makes the overall joinery simpler as shown in the diagram.
Laminating the apron
Construction begins with the bending form of laminated pine, easy to shape but stout enough to resist the considerable forces of bending. I pay attention to making the form symmetrical and the face square to the bottom surface. The position of the clamps must be thought out so that each of the 20 or so used has a nice square perch on the form and won’t slip as they are tightened.
3. Fitting the rear apron with a pattern piece. The legs have already been fitted to the front apron (more difficult) and dry assembled to get the exact angles of the shoulders (and position) of the rear joins on the pattern.
I resaw the laminates on my bandsaw, hand plane them a bit to smoothness, especially the inside and outside faces. Five, about 3mm thick, are needed, and a few extras for cauls on the outside to protect the face and spread out the clamping forces. A centreline on the form and laminates helps to get everything aligned while gluing up, and later to orient the apron on the drawing. I use a long open time glue, Unibond 800.
4. Showing the angled joins of the rear leg to back rail. The legs are not square to the rail, but angled in 10°.
5. When laminating the apron, plan ahead which clamps will go where to ensure firm, even pressure.
6. When the glue is dry the apron comes out of the clamps.
7. Showing the different layers of the apron.
Tapered leg work
The legs start as a simple pattern out of thin pine. A pattern lets me quickly see the taper, size of the top of the leg and the position of the cuff. And then I can lean it against my bench to get a sense of it. I use this pattern to cut out each leg, orienting it on my stock to get the most pleasing flow of the grain down the leg. I slice out each tapered leg blank on the bandsaw or tablesaw, along with an extra or two, and make these an inch or two longer than I need.
8. Garrett Hack tapers the legs on all four sides using the bandsaw or tablesaw. The pattern doubles as a jig to carry the leg. The sawguard is removed for photo visibility, and the saw is not turned on.
By hand I can refine each leg — square and true to the pattern. or I can use my pattern as a jig against a fence; the tapers of leg and pattern are reversed against one another so you can saw out very accurate legs. the pattern will later become a story stick, laying out the joinery, cuff, top and bottom of the leg. Since my legs are symmetrical all around, I can choose the best face for a primary face. to keep track I mark each one, and the leg’s position on the table (numbering 1, 2, 3, 4 works).
9. To hold the curved apron at the right angle when cutting the tenon on the tablesaw, a support block of wood is cut. The drawing is used to mark out the block.
I cut mortises on a slot mortiser that is quick and accurate. position and depth of each comes right off the drawing. the haunches I mark and chop out by hand. they are quite shallow in order to preserve as much of the integrity of the top of the leg as possible. tenons I cut with double blades on my tablesaw with spacers between them. Fig.1 shows the angle of the rear tenons of the curved apron.
10. Looking down onto how the laminated apron sits into the front leg.
A good way of holding the curved apron at this angle is to cut a wood block that nests against the outside of the apron (double-sided tape holds it) and that has a flat outside parallel to the tenon angle. the flat side goes into my heavy tenon jig on the tablesaw, holding the apron at the correct orientation. Shoulder positions and angles come off the drawing. each has the slightly out of vertical taper angle as well. I saw these by hand and adjust them with a shoulder plane.
Front leg bridle joints
Before cutting the bridle joints for the front legs I clamp them in place to finetune their placement. Since the top of the leg is tapered I cannot just cut a typical bridle and slide the leg on. Instead I cut a straight dado into the apron face nearly the depth of the face lamination, and a little less than the width of the leg. this adds torsional rigidity to the joint and solves the taper problem. A small margin of the leg overhangs this dado. What remains of the apron thickness is strong, and there is plenty of leg strength at the rear. the deep open mortises on the legs I cut with the bandsaw and clean up with chisels.
11. The recessed (dadoed) front apron slides into open mortises cut on the bandsaw and cleaned up with chisels.
Any small inaccuracies in the legs (out of square) or joinery thus far show up when cutting the tenons on the rear apron. At this point I am no longer using the drawing but ‘working to reality’. With the curved apron dry fit and assembled to the legs, I make a thin pattern of the rear apron, complete with shoulder angles, and angles of the tenons. These I find by sliding a long ‘tenon’ into the mortise and trace the angle of each end on my pattern. I either tape this to my rear apron or transfer the lines and cut the tenons with the same double blade set-up.
Making and adding cockbeads
Details with both aesthetic and practical functions appeal to me. A cockbead applied to the bottom of the aprons creates a nice dark highlight, it rounds and protects the edge, and it conceals the laminations. I first plane the stock to 3mm thickness by hand, and then shape the front edge to the exact curve of the apron where they fit and projecting about 1.5mm beyond the apron.
The bead profile I shape with a simple scratchstock with a scraping cutter. It’s easiest to get the length and angles where the cockbeads meet the legs before gluing on the front legs, but I leave them long for exact fitting later. When I do glue them in place they are slightly proud on the inside, which I level down with a spokeshave and card scraper.
12. Creating detail on legs.
When to add details
13. Framing crotch veneer and mother of pearl with bandings.
Inlay and cuffs and any other details I complete before assembly. If it’s something new or tricky I might even cut the inlay before any joinery, so I can start over again if I have to. Cockbeads are added after assembly, but I make them before I add the front legs, slightly long, but with the tricky angles where they meet the legs well started. I cut the bottoms of the legs to length too, using my pattern.
14. Leg detail showing inlaid veneer, banding and cockbeading.
Assembling the frame
Assembly starts by gluing the rear legs first to the rear apron, then to the curved front apron. Lastly each front leg is joined with bridle joints. Clamping on the curved apron is always challenging. I’ve taken to getting the best fit I can and sliding together the joint, no clamps. The curved blocks used to cut the tenons are of some use to clamp the apron, double-sided taped and clamped on well.
Next I cut off the tops of each leg projecting above the aprons. I do this step after glue-up just to preserve maximum strength of the leg during this stressful time, and it’s easier to get the angles correct. Using a long plane I level around the top of each apron and leg, and work into the table at each leg to avoid any tearout on the outside faces.
Top curve and underbevel
Shaping the top at this point, to a smooth fair curve and deep underbevel is pure joy. The top is a structural element strengthening the table. A single board top is always my first choice. The underbevel makes the top appear much thinner and elegant, as well as allowing more of the apron detail to be seen. To mark out the curve of the top I flip the table over on my bench and trace around the apron with a small spacer equal to the overhang. To mark where the underbevel stops I use a narrow spacer and a block plane to fair the curve, then a drawknife to rough out the underbevel and finish it with a block plane and spokeshave.
Coat of many layers
For a finish I love the dazzle and ease of shellac. Lately I have been using seedlac, a coarse product with plenty of impurities, but brilliant colour and clarity once it settles. I brush on a several thin layers, let it cure overnight, and then level the surface with a light pass of a scraper with no burr. The scraper is quick, and leaves an almost polished surface. After a dozen or so coats I shift to a pad and French polish another dozen. For maximum protection I pad on a layer or two of thinned down wiping polyurethane, buff, and wax.
First published in Australian Wood Review issue 80, 2013
Garrett Hack is a leading US furniture designer/maker, see www.garretthack.com