The design for this project was in my head for a long time, starting with the idea of a dining-sized X-Table. A metal base large enough would be very heavy, which made me move in the direction of separate trestles. I was also interested in using wood in a more structural manner than just the top.
The Arc Trestle Table is composed of four parts -- trestles, rail, and top -- interlocking with no fasteners at all, making for a knock-down design that assembles in seconds.
Building the rail required bending five layers of very stiff Afrormosia wood over a massive arced form, using a large number of the strongest clamps I had on hand. Even so, it was impossible to bend all of them at once, so I built it up by gluing one layer at a time. Once the glue was dry, the whole part ended up being incredibly rigid.
Later on, after the trestles were built, I did the final shaping work and added the angled slots on the underside of the rail to ensure a snug fit across the trestles.
For rigidity, the trestles are constructed as trusses, hammered at the anvil from mild steel bar stock into the correct angles and then TIG welded together with plate steel connections. This triangular truss design allows the legs to achieve a semicircular arc with almost no flex.
Heating the steel with an oxy-acetylene torch with a small tip allows bending in a very specific spot.
Once I'd come up with the truss design and worked out the math, I went through three iterations of how to construct the trestles before ending up with the triangular plates the final piece used.
For the top, I used some Claro walnut I had purchased for another project a few years ago but decided was too nice, so it waited for a worthy project. It had been stored someplace moist, and had lots of splits and black water stains, so assembling it into a nice top was some work.
The weight of the top further solidifies the structure; strategic notches where the wood meets the metal create tension with the trusses to lock everything in place.
Dealing with the splits and voids required a fair amount of epoxy filling, which I tinted black to blend in with the dark water damage stains.
After all the patching, filling and sanding I began the finishing process, which ended up with about six coats of General Finishes Arm-R-Seal, an oil/urethane blend I've been using for many years. Rubbed in by hand with rags, each coat takes a day or so to dry before light sanding and applying the next. An oil finish like this gives a rich depth that is hard to achieve otherwise, and the urethane blended in gives a bit more durability without creating a plastic-feeling film.
To prevent the steel trestles from rusting I heated them with a torch and brushed on paste wax, creating a finish which seals and darkens them somewhat without removing the color variations left by the heat of the earlier fabrication steps.
As with many of my projects, I gave the wooden parts a final paste wax coat and polish before calling it done.
The Arc Trestle Table ended up being rather different from my original musings, but I'm extremely pleased with the piece, and look forward to exploring more of the themes that it brought forth in future work.