I finished this project up just before the new year—a dining table for friends who just moved here to Seattle from the Bay Area. (In our rainiest winter in ten years. It’s not always this bad, honest.) They wanted a table that would seat eight in a pinch, but also be possible to disassemble for moving or stashing away for dance parties. The classic trestle table plan fit the bill, and as an engineer I like things that are minimalist and functional. A trestle table is essentially two wooden I-beams joined together along the width by a single stretcher and the tabletop itself. As far as table size to materials ratio, it’s hard to imagine better. And I just really like the shape. My friends had very compatible ideas about design, so it was a great learning experience and a very gratifying project to sketch this out with them and build it.

 

I looked at a bunch of plans for trestle tables on the internet. The one I took the most from directly was this plan for a Shaker-derived table from Popular Woodworking Magazine. Though I made a bunch of changes to the design, the detailed discussion of techniques in the article was crucial. Two techniques I took directly from it were drawboring, and gluing a double-thickness of lumber to create the feet.

Drawboring is an ancient technique peculiar to the woodworking craft that is just cool. I used it at both intersections where the I-beam is held together by the walnut dowels. It’s a woodworking thing only, because it depends on the ability of wood to compress a tiny bit. Basically you lay out everything as if you are going to fit the dowels through the mortise (rectangular hole in the foot) and tenon (part of the upright that goes in the hole) and then out the other side. But then instead of drilling the holes in the tenon in line with the holes in the foot, the tenon holes get offset a tiny bit, 1/32″ or so. This pulls the tenon piece into the foot when the dowels are pounded through, putting the wood in a little bit of compression and keeping them locked together.

The double-thickness feet made construction a lot easier. Mortises need to be square, and there are two ways to cut them: expensive and specialized power tools that I can’t justify having, or a lot of hand chiseling. That’s a lot of hand chiseling to get through the 3″ by 3″ foot. So I used an idea from the article and made the feet out of two sections of 1.5″ by 3″, glued down the center. This way the mortise can be cut on the table saw using a dado blade. The traditional Shaker design is painted, which makes this come out seamlessly—I didn’t want to paint the table but spent some time matching the grain on the halves of the feet. While you can see the line where they are put together, the grain does nice things and I am happy with the result.

The tabletop size was one of the things my friends had a pretty firm specification for: 72″ by 32″. I had seen a material at my favorite neighborhood store, Ballard Reuse, that I thought could work and be a small fraction of the cost of a new hardwood top. It’s recycled crate lumber sourced from Boeing. A full inch thick, it’s made of a variety of tropical hardwoods that are all very hard and dense. Cool looking stuff, though I don’t know what these crates are for—holding airplane parts I guess. They would be sturdy crates. One one side there are some mounting holes every two feet, and both sides have a fair amount of bigger voids that are filled in with some kind of putty. It took us a little while to find a couple of pieces that matched well and had only a few of the putty holes. Time well spent. The holes were all less than an inch wide so we decided not to fill them in with epoxy or anything, and just got rid of the unattractive putty.

I proposed alder for the rest of the table lumber: the I-beams and the breadboard ends. I’ve always liked alder. It’s from the Northwest, and not expensive for a hardwood, and I think it goes very nicely with the colors of all the different woods in the crate lumber.

The slanted keys in the stretcher and the dowels are walnut. Five degrees is the right angle for these little guys, and the mortises in the ends of the stretcher are cut to match. This was a fiddly operation involving a lot of making five-degree-slanted scaffolding to hold the stretcher on, a little drilling on the drill press, and then a lot of hand chopping to square up the holes.

 

The alder ends tie the whole thing together visually and hide the end grain, which I think would look too raw on its own. They also help keep the top from warping. I cut the tongues in the table top by running a router over them, and the grooves in the ends on the table saw with the dado blade. I ruined one end piece by trying to cut this groove with my router in one pass. I used my router table and fence—everything seemed to be going fine—but some nasty vibration was kicking against the fence and pushing it out of place and the groove went frrrrrp… into more of a J than a straight line. So I got the dado blade for my table saw that I’d been wanting an excuse to get anyway, and that went fine.

The ends are held on just with a single dowel that shows underneath and some glue around it for about 2″ on either side. The rest of the joint is free to slide, because the table top expands and contracts with changing humidity and temperature, and would crack otherwise. The top is held in place on centers of the I beams with dowel pegs that it sits on, and farther out on the arms with “buttons” that also let it move. When I put it together in the shop I made the top and ends the same width. In this detail you can see how the top shrunk by around 1/8″ a few days later.

The top is finished with four coats of Daly’s Profin, and paste wax over that. Opinions on the internets about finishing dining tables vary widely, and this is my first one, so I’m interested to see how it holds up. If the Profin (like other “Danish oil” finishes, essentially) doesn’t wear well enough in this application, I can repair it and add a polyurethane coat for more durability. But poly tends to add a sealed, plastic quality, so I’m avoiding it if possible—time will tell. (You guys knew you were getting an experiment, right?)

One thing I would do a bit differently is make the I beams just a few inches wider. They are 30″ wide and the top is 33″. If you sit right on the long edge of the table, and you are a medium-sized person, you can make the whole thing lean. The lean starts slowly, and would only become a problem if everyone was pretty drunk. Obviously the Shakers didn’t worry about this, so I’ll try not to.