Laurent Peacock outlines the techniques used in the joinery of his Sika console table.
When designers seek inspiration for new work, the old edict ‘form follows function’ is often a solid starting point. However, when I began developing ideas for a speculative console table design, the relative absence of a specific function to design around prompted me to look further for inspiration. I’m certainly neither the first nor the last designer to be intrigued by the natural world, but as design stimulus I find it far more useful than looking at other man-made objects. I wanted my design to be primarily a study in form, and also to be imbued with a sense of character or personality. I guess in some way it was inevitable then, in developing a design for a tall, skinny, leggy table informed by nature, that an animal-like feel would emerge. The resulting design has the poise of a baby deer, reinforced through the choice of materials: delicate, pale rippled sycamore (Acer pseudoplatanus) for the legs and the richer, heavily figured grain of silky oak (Grevillea robusta) veneers for the body. The main challenge was to find a way to harmoniously combine the curved forms of these different design elements while doing justice to the materials.
Sika Console Table plan
Laminating the cross-brace
The silky oak I had chosen was only available as knife-cut veneer, however, I wanted to create a solid, sculptural cross-brace to provide structural support for the legs. To achieve this, I stacked and laminated around 60 layers of veneer over a curved former using epoxy resin and a vacuum bag. To speed up the layer shaping process and minimise material wastage, the lamination was a two-stage process. The first glue-up comprised around 25 layers along the full length of the former, with the thicker second stack of 35 layers just covering the central section.
Once released from the former, the sides of the lamination were flattened off and squared up by a couple of runs over the planer, to provide reliable references for marking out. The crown of the curve was bandsawn off, prior to being slowly and carefully flattened with a hand plane. It was crucial to get this surface totally flat so as to avoid an unsightly glue line at the next stage. The ends of the crown stack of veneers were also planed flat and symmetrical.
The part was next bandsawn in half along its length, and the two resulting halves rotated to meet flush along the newly flattened surfaces. Prior to gluing the two halves together, the one remaining critical step was to ensure that the ends of each half, which would later become through-tenons in the leg joints, were perfectly flat and parallel. This involved painstaking work with block plane, hard sanding block and straightedge. Once test-fitted within each of the leg joint mortises (more on those later) the tenons were taped up for protection, not to be touched again. The two halves were glued together, again with epoxy, and the remainder of the work on the cross-brace involved hand shaping with rasps, files and sanding blocks.
Choice of joint
From a structural point of view, it was by no means necessary for me to use a through-tenon joint, particularly of this size. However, having experimented with the silky oak veneer in the early stages of the build, I’d discovered the rather lovely end grain pattern that emerges when layers of the veneer are laminated together. I felt it would be a real shame for this feature to be concealed in the final construction so I chose to project the tenons right through to the front of the leg joints. This was, admittedly, a risk, as any imprecision here would have been plain to see, but the methodical approach to creating the joints helped ensure these were up to scratch.
Angled leg joinery
The first challenge to address with the legs was that of creating the angled joint. In order for the final joint line to be horizontal, this involved cutting mitres at two different angles; a straightforward enough job with the duplex on the tablesaw. The more challenging element was the cutting of the mortises to receive the through-tenons of the cross-brace. I decided that attempting to cut the through-mortises after the angled joint had been created would be unlikely to yield the high level of precision necessary, given the width and length of the tenons. Any gap or inaccuracy would be painfully evident in the final joint, with very little room for correction. So instead I cut the mortises in two halves before the stock was jointed. This allowed me to use a square-ended cutter on the router table. I created two different angled jigs to support the two leg components as they travelled over the cutter. Only routing to a 3mm depth on each pass required more than 90 passes over the router for the eight components, with pieces being clamped and unclamped each time. So, it was not a speedy process, but it resulted in mortise slots that were parallel, consistent in both width and depth and with perfectly square bottoms.
The wide tenons of the brace would ultimately provide a great deal of strength to the joints once assembled, but this assembly would only take place at the very end of the process, so I was concerned that during the shaping stage the end-grain leg joint would be weaker and more vulnerable. I therefore incorporated small Dominoes within the joint, in locations that I knew I would not expose through the shaping process.
To achieve a clean, unobtrusive glue line in the pale sycamore of the final joint, I needed to be able to apply sufficient clamping pressure. When joints come together at unconventional angles this can sometimes be tricky. Knowing that the legs were going to be shaped later on in the process anyway, I glued the offcuts from the earlier mitre cuts directly onto the timber to use as clamping blocks. These were later flushed off without trace. I also cut sacrificial dummy tenons that could be used for alignment during glue-up as well as providing an extra degree of mechanical reinforcement during shaping. These dummy tenons were very carefully dimensioned and waxed before insertion, so as to ensure they could be slid in and out once the joint had been formed around them.
Shaping the legs
Given the nature of my leg design, with tapers on all sides combined with compound curves, I knew that the majority of the shaping would need to be done by hand. I was, however, able to rout the internal curve first of all, while the other sides were still square and parallel. I used a toggle clamp MDF template jig and a bearing-guided cutter to replicate the desired curve across all four legs. The dummy tenons were to remain in place throughout the shaping process, both for joint strength and also to limit the risk of breakout or tool damage to the corners of the mortise slots.
Knowing that the work would largely be done by hand, my key concern while shaping the legs was that of ensuring consistency across all four. I decided early on to break the process down into a series of small steps, each of which would be carried out on all four legs before moving onto the next. This meant that I was able to make effective use of reference marks and guide lines at each step.
Both the top and bottom ends of each leg were tapered on both sides, prior to further angles being marked out. Wherever possible for the flat facets in the design I used a block plane, which provided a great degree of control over angles and yielded crisp edges and a smooth surface. This was particularly helpful for the multi-faceted areas around the backs of the joints. The main sweeping inner curve of the leg was formed initially from a number of spokeshaved flat facets, which were later blended together into the continual smooth curve of the final form. With both the brace and leg shaping finished, the tenons were glued in place with UF glue, to allow for a degree of fine-tuning while fitting. The ends of the tenons were carefully flushed off and blended in with the curves of the legs.
Clamping awkward-shaped parts in the vice
While shaping, my bench vice wasn’t too successful on its own at preventing the leg from rotating. I found that clamping a simple board horizontally to the top of my bench and using that as extra support provided all of the stability I needed.
