How to Make an Andon-Style Kumiko Lantern

TRANSCRIPT

Hi, I’m Andrew Strom, and today we’re going to build an andon. This is a modern version of a traditional Japanese lamp. You can see what an attractive project it is. It’s useful and would make a great gift. One of the great things about this project is the blend of machine work and handwork. We can cut the mortise-and-tenon joinery by machine, then balance that with the handwork of producing the kumiko panels. So, let’s dive in.

We’re going to start by constructing the body of the andon itself, then fit the kumiko panels to it afterwards. It’s built using fairly straightforward mortise-and-tenon joinery, but there are a couple of subtleties to go through before we get too far.

The inside faces of the legs and rails are rabbeted to accept the kumiko frames. The rabbets on the legs are stopped rabbets: they don’t travel the full length, so we have nice square corners at the top and bottom of each leg. Additionally, the mortises are offset in the legs. There’s a reveal on the front face of the rails that gives us a little detail—a nice shadow line. Because the tenons are centered on the rails, the mortises need to be offset so that the back of each rail is flush with the inside of the leg.

Because of that offset, the mortises intersect inside the legs. That’s an important point to be aware of when we’re cutting them. You can see I’ve got one of the legs here with its two stopped rabbets. The tenon is centered on the thickness of the rail, and I’ve mitered its end so that the two tenons can come together inside the leg. This gives me the maximum tenon length in the leg and adds strength to the joint.

We’re going to start by cutting the mortises. I’m using a hollow-chisel mortiser, but if you prefer another method or are constrained by your tooling, a plunge router followed by a chisel to square the ends works as well. I’ve laid out the mortise locations, and you can see that they’re offset toward the rear of the leg. I’ve also scribed a marking-gauge line on the pieces I’m going to cut to ensure that the correct face of each leg is always registered against the mortiser’s fence.

Here’s a tip for cutting intersecting mortises: when machining the first mortise, don’t cut it to its final depth. Leave some material to remove when you cut the second mortise. If you cut the first one to its final depth, there will be unsupported wood inside it, which can lead to tear-out inside the leg.

Cutting the mortises is fairly straightforward. Because they’re offset, I’m ensuring that the correct face is always registered against the mortiser’s fence. I begin with a plunge cut at the end of each mortise. This supports the chisel on all four sides and prevents it from twisting or deflecting. With those cuts made, I come back and remove the remaining waste.

I’m using a table saw to cut the shoulders of the tenons. Since the rails are all exactly the same length, I can use a stop block on the miter gauge. I’m using a bandsaw to cut the tenon cheeks. This setup is a bit tricky because this cut determines the fit of the mortise-and-tenon joint.

Because the rails are relatively short, I’ve cut their rabbets on the router table. The safest way to cut the stopped rabbets in the legs is with a plunge router and edge guide. Here, I’m making successive passes to maintain good control over the router and get a clean cut. The rails and legs have chamfers on three sides, and the quickest and safest way to make those cuts is on the router table.

With the machine work complete, it’s time to test-fit the joinery. Before I do that, I need to square off the stopped rabbets in the legs. That’s straightforward: I’ll use a chisel and work to the layout line that corresponds to the end of the mortise. Then I’ll fit the tenons to their respective mortises and miter their ends so they come together neatly inside the legs.

I’m happy with how everything went together in the test assembly, so I’m ready to glue it up. When I disassembled the andon, I numbered all the joints to keep the pieces organized. I’m going to glue it in two stages: first, the opposite sides, and then the final assembly.

A couple of tips before I start. With mortise-and-tenon work, I find that applying glue to the mortises rather than the tenons minimizes squeeze-out. I’ve also made spacers to insert into the openings. Their widths are determined by the shoulder-to-shoulder distance on the rails, but there’s a little play in the length of each mortise. The spacers will ensure that all the openings end up the same size, making it easier to fit the panels. Now that the glue has dried on the first two sides, it’s time for the final assembly.

Next, I’m going to cut the kumiko panels. For two of them, I’m using a decorative pattern called soroban, the Japanese word for “abacus.” The hexagonal shapes are an abstract, stylized form of abacus beads. If you’ve never cut kumiko before, this is a good place to start. It’s a fairly simple pattern, but it provides practice in cutting and fitting the joints before progressing to more complex patterns.

To begin, I’ll cut the half-lap joints in the horizontal and vertical elements, then fill in the angled pieces that make up the pattern. I’ve created a story stick with the positions of the intersecting bars. We’ll gang all the pieces together for two reasons. First, it’s a tremendous time-saver. Second, keeping the pieces together in the order they were cut compensates for any small deviation in my cutting. If I turn the pieces end for end, small differences in the positions of the half-lap joints could make the bars wavy. I’ll keep them in the order in which I cut them.

To cut the joints, I’m using a small dozuki saw. It has a thin blade that leaves a fine kerf and a spine for stiffness. That rigidity helps me cut a straight line. I’m going to cut down a quarter of an inch. The fence on the outside of my cutting jig is at the quarter-inch mark, and I’ll use a quarter-inch-thick piece of stock as a gauge to tell me when to stop cutting.

Here you can see the fit I’m looking for: a firm press fit. It shouldn’t take force to put the pieces together, but it shouldn’t be too loose either. I’m going to make the rest of these saw cuts.

I’m ready to assemble one of the panels. My vertical and horizontal kumiko pieces are organized in order, and I’ll start at one corner and work my way down and out. I find that easier than assembling the perimeter first and trying to fill it in afterwards. The bars go together more easily this way.

A couple of words of caution: you’ll need gentle force to press the pieces together. A tapping block and a few light mallet taps are acceptable, but don’t go beyond that. Also, use your ears. If you hear fibres cracking, stop and assess the problem. Ease some of the contact surfaces if needed, then try again. Work slowly and methodically.

The soroban pattern uses two kinds of pieces: hinge pieces and a locking piece in the middle. The hinge pieces extend from the corners at a 30-degree angle. When the locking piece is pressed into place, it puts the hinge pieces into compression and makes a very tight joint. You don’t have to glue it, though I like to add a little glue for insurance.

First, I’ll cut the hinge pieces. They have a 60-degree angle and a 30-degree angle on one end, and two 30-degree angles on the other. To make those angles, I’m using a jig: a block of wood with a half-inch groove and 30-degree and 60-degree cuts at the ends. I’ll use those angled surfaces to pare the corners of each joint.

I’m in the home stretch now, fitting the kumiko panels to the andon’s frame. I’m using a shooting board and block plane to trim them to size, aiming for a press fit. I want the panels to stay in the rabbets without adhesive so they can be removed if we need to replace the paper. The fit should be firm enough to hold them in place, but not so tight that inserting them takes force. The kumiko panels are moderately delicate.

As I’ve fitted each panel, I’ve used transfer film—a very thin double-sided tape—to apply Japanese paper. It’s known as washi, and it’s made from mulberry fibre. It’s the traditional paper historically used for these lanterns. It’s nicely translucent, and I’ve chosen a green shade with fibres of different colours that I think will complement the maple frame.

I’ve wired the andon using lamp hardware from my local hardware store. I’m going to leave the maple unfinished rather than apply an oil that would bring out the yellow tones maple sometimes has. I’ll let it age naturally, which I think is in keeping with the spirit of the project. I also like the contrast the fibres in the washi provide against the geometric regularity of the frame.

It’s been a fun but moderately challenging build. I hope it inspires you to give it a try. Thanks very much for joining us, and we’ll see you next time.