A table can essentially be broken down (and built) as two separate parts: the base and the top.  I’m going to start building the base first.

Part of what consummated the decision of building a replacement table (told here) was the fact that a bump into the table would cause it to sway like a tree in a storm.  To construct a rock-solid table, the joint of choice is the mortise and tenon.  I’ve never done these by hand yet.  What makes this particular table build intimidating is that I want it to be in the Arts & Crafts form as the original was… which, in going beyond the mortise and tenon, means through mortise and tenons.  Fake through mortise and tenonThese are intimidating because they showcase your work: you want the mortise (the hole) to show no space as the tenon (the peg) is fit into it and protrudes out the other side (which is the part people see).  The original table that I’m replicating has through tenons… through fake tenons (pictured at right)… they’re really just little rectangular pieces of wood (caps) glued opposite the beams to look like through tenons.  I won’t do that; I’m a firm believer that if you do a job, do it right.  True through mortise and tenons are what I will be using.

I used mortise and tenon joinery for my workbench (showcased at the top of the Blog), but at that time I used a mortiser machine.  I hated that machine.  In the light of not doing practice cuts, you had to set it up just perfectly to stay in your lines, and then drill out little by little as you’d move the machine back and forth.  As the bit rotated around, it would sometimes go deeper or shallower, or even run and rip out some wood a little past the line.  It was sloppy joinery on my part, but for the bench, it was tight enough (since I cleaned it with a chisel and cut the tenons to match it afterward).  Because of this experience, I was pretty weary of hand-chopping 16 mortises with their tenon counterparts, of which half of those (8) will be through mortises with exposed, visible tenons.

Mortise and Tenon by Frank KlauszSo, the obvious warm up is to start with the stub mortises (the ones that don’t go all the way through).  I bought a mortise video by Frank Klausz that actually went a long way to help me prepare and understand how to do this, as well as beefed up on Roy Underhill’s Panel Door show (which primarily used mortise and tenon).  Watch it by clicking the link if you wish.

Hand chiseling the mortiseMy first practice mortise was the real thing… on the upper leg of my elm table.  I found it to be easier than using a mortiser!  Marking everything with a straight-edge and marking knife probably took 2 or 3 hours, but that was fine.  After marking everything, I decided to go with ½” wide mortises for the legs.  As long as the chisel is as wide as the mortise is, you only really need to mark one side of the cut (which makes it nice), because the width of the chisel will automatically form the opposing wall.  In Elm, it only took 3 sweeps of chopping (back, forth, back) to get the mortise to the desired depth: about ⅔ of the way through the 2½” legs.

A pointer: stand in line with the mortise that you are chopping (like your point of view in the picture at right), rather than beside it (at the front of the bench from the picture at right), to ensure the chisel is perfectly square to the walls of the mortise.

I chopped the first two mortises, cut the tenons, and gave it a test fit: perfect… and way more pleasurable than using a mortiser, though my back was getting a little achy from constantly standing on the tile floor and bending over the mortise.  I tried a few chops from sitting down and it just doesn’t work; you don’t get the same point of view to maintain good chisel control.

One leg joined up

Next was the through tenons at the bottom of the table.  I thought of doing this in two ways: 1) I can chop the mortises, then taper the legs or 2) I can taper the legs first and then chop the mortises.  I went with option 2 because, with through tenons, you see the final product… my chops may have been a little sloppy under the surface, and I didn’t want to taper the legs and find that out.  So off to taper the legs.

I don’t know what angle I tapered them to… I wasn’t using power tools, so it really didn’t matter.  I just went to the bottom of the leg, marked ½” in, and drew a line connecting that mark with the outside of the leg at the top.  I used a saw (sloppily) to get rid of as much waste as I could outside my mark line, then turned to my Jointer Plane to bring the taper down to the line.  After doing this 16 times (4 legs, 4 sides per leg), my triceps were pretty damn tired.

Tapering a leg by hand

Now for the tricky part: marking out through-mortises on tapered legs. Since none of the surfaces are square, I had to devise a way to make accurate marks. What I ended up doing was using a straight scrap board (that was squared up) and setting it next to the leg: the top of the leg and the board were clamped together, and as the leg tapered down to the foot, there was more and more space between the leg and the board. From there, I made my marks using a square referenced against the scrap board.

I cut the mortises more or less the same, but since they’re through mortises, it requires a few extra steps. I started from the outside or “show” side (where people will see the tenon coming through the hole). Staying about ¼” from each end, I chopped about ¼ through the leg.

Chopping a Tapered Mortise

I flipped it over to the “shoulder” side and chopped all the way through to meet the hole from the other side. In two of the legs, the two holes (from each side) weren’t exactly aligned – I would pare out the wall as required to align them from the current side I was working on (the shoulder side). The reason? Yes, this wouldn’t be “the perfect” joint, but the shoulder of the tenon would cover up any spaces caused by widening the wall to meet the opposite side’s wall. Once I made this correction, I’d do the final two chops to bring the mortise (length-wise) to the line on the shoulder side, then flip the leg and make the final two chops on the show side. It worked pretty well.

Through mortise and tenon table base

So, here’s where we stand now… 12 mortises down, 4 to go (the 4 mortises that will go through the table top surface to connect the top to the base).

The Table so Far

I still need to shape the bottom rails and mount the bottom shelf to them… but I think I’ll move onto the table top next.

Tagged with →