I hate fiddling with joinery. If you’ve cut many joints, inevitably you run across one that you have to fuss over and massage until it finally goes together…
…only to find it’s thrown another joint out of alignment and the whole thing starts over again.
So to affix the shelves to the sides, we’re using a housed, through-tenoned, wedged joint. Robert Wearing, one of the contributors to woodworking canon, says it gives a very strong carcase. Strong is good! So here we go.
I’m using a technique I saw Chris Schwarz use in one of the multitudinous Popular Woodworking books so I don’t have to do as much fussing with the joint. You make a shallow rebate along the edge of your shelf, and fit that to the housing, rather than the full width. This may seem unnecessary, but it really does help with the fitting. So first, I’m going to cut the housing. You can use a saw to cut the sides, but I just use a chisel and mallet. Knife lines defining the edges of your housing keep everything crisp.
We’re going to be using the router plane a lot on this build, and evening out the bottom of the housings is the first application for it. You might not technically need it, but I for one wouldn’t do without it. Once the housing is cut, we can use it to exactly cut the rebate on the shelf to match. Gauge a line from your marks, and cut the rebate to fit. You could use a moving fillester plane to cut this, but again I just use a chisel, mallet, and router plane.
You might have to take off another couple of layers of wood when you offer the rebate to the housing, but with the router plane it’s just a quick turn on the depth adjustment. No big deal. Work on it until it fits snugly. A properly fitted housing joint should stay together from its own friction during a test fit.
Yes, that really does fit! The extra length in front of the shoulder is for the tenons which pierce the sides. We’ll lay those out next. If you read the excerpt from Wearing above, you might have noticed he said that big tenons weren’t helpful. Therefore I’ll lay out pretty small ones. Here’s a design feature: since the sides narrow towards the top (we’ll get there), we can decrease the number of tenons for each shelf, giving a stepped effect. It will also keep us from puncturing the same spot in the grain over and over, preventing the formation of a weak spot in the side. I lay these out and cut them like dovetails. BE SURE to mark your waste adequately. It’s very easy to cut the wrong part since they look so much alike, especially in the middle.
Once the tenons are cut out, I offer them to the carcase side, and mark where they’re going to penetrate. It’s kind of a finicky maneuver, but it’s the best way I know to keep them in line. Once the mortices are marked, cut them out. BE SURE to cut the face side last. This way, if there’s any splintering, it’s inside the case and inside a housing where it won’t be apparent. You can bore the mortice out with an auger, then clean up with a chisel, but in woods that have a big differential in hardness, like this yellow pine, I don’t like to do that. Invariably I hit a bit of hard, dark latewood and that deflects my auger into the softer, lighter earlywood. Instead, I just chop them out with a chisel and mallet. You machine tool guys with hollow chisel morticers can keep your snide comments to yourself, thank you.
You might have to do a little fitting, but it should come together in the end. We’ll go over wedging later, when we do the final assembly.