This hardwood and bamboo sushi tray is a traditional Japanese shape with modern flair, including beveled edges and built-in butterfly chopstick rests.
My wife and I wanted to present my brother and his wife with a nice sushi set, but we were disappointed with the offerings available commercially. Naturally, that meant I would design and build one myself. Because presentation is just as important as preparation with many customary Japanese foods, I started with a traditional “geta”-style tray and added a few elegant touches of my own.
Geta are traditional Japanese sandals, made up of a flat piece of wood for the sole with two cleats on the underside. My tray begins with the same design, but I’ve dressed it up using breadboard ends with butterfly splines, dovetailed legs, and built-in chopstick rests. Bamboo has an inherently oriental look, so to me it was the only choice for the body. I picked purpleheart for the splines and cherry for the breadboard ends.
Fast-growing bamboo, which is actually a grass, is rapidly gaining popularity as a substitute for wood. Engineered bamboo planks are smooth, stable and environmentally friendly. Bamboo grown for lumber can be harvested every four to six years. The 6" stalks are cut into strips, then glued into planks, plywood and flooring. You can read more about using bamboo in this issue’s Woodsense.
Bamboo planks can still be a bit hard to find, unless you’re lucky enough to have a local supplier. A flooring wholesaler near me does carry bamboo flooring and stair treads, but the flooring is too thin for this project and the treads would need to be milled down from their 1" thickness to be usable. Chris Miller at Northwest Bamboo came to my rescue by shipping me an unfinished stair riser. At ¾" thick and 7½" wide, it was perfect for the tray, and a 6' riser is enough material for several trays. The plank was perfectly machined and usable just as I received it.
Sushi trays seem to traditionally be about 7" wide by 10" long. I increased the size a little to compensate for the chopstick rests.
The first step is to mill the hardwood stock for the legs, splines and ends. I always harp on proper stock preparation, and it’s a crucial component of this project. The stock must be very square and straight to ensure close-fitting joints.
Prepping the stock
Using 24" blanks of stock, I milled one to 1¾" wide x ¾" thick for the ends, and two others to 11/4" x ¾".
The smaller blanks will form the legs and splines, so I made one in cherry and the other in purpleheart. The splines can be virtually any contrasting wood, but should be tightly grained and clear of defects. The 11/4" was determined by the size of my butterfly bit; your bit may require a different size.
The ¾" thickness of the spline stock is also determined by bit size. My dovetail bit was ¾"; you can minimize the look of the splines by using a narrower bit. Just be sure it is 14° to match the butterfly bit. I’ve also included instructions on making the splines using the dovetail bit in place of the butterfly bit.
With the hardwood milled to width and thickness, the body and breadboard ends can be crosscut to length. Using a zero-clearance insert and my miter gauge, I crosscut the bamboo to 10½" and the ends to 7½", ensuring that the ends are an exact match to the width of the bamboo. This is critical since the key slots in both the body and the ends will be referenced from the outside edges and must line up in order to work. The bamboo is quite hard and rigid, but cuts cleanly and easily.
Milling the slots
The bamboo body needs two dovetail grooves cut into the bottom to accept the legs, and two through each end for the keys. To ease the machining at the router table, I precut undersized dados through each keyway (Fig. 1). This allows for adequate chip clearance, improving the cut quality and extending the life of the dovetail bit.
The narrow part of my dovetail is ½" wide, so I set the dado blade for a 7/16" cut. I set the height to a little under 3/8" and crosscut the grooves for the legs (Fig. 2). Make sure you have a good backer behind the cut to minimize tearout. To reduce setups, the legs and the butterfly key slots are both cut 1¼" in from an outside edge.
I reset the dado height to just under 9/16" and cut the key slots. It is important to cut the bamboo body and the cherry ends with the same setup to ensure that the key slots line up.
Now the dovetails can be cut. Set up the router table with the dovetail bit at 3/8" high, ensuring that the bit will completely cover the leg slot. Again, I found the bamboo to mill quite nicely giving a smooth clean cut, but make sure to support the backs of the parts (Fig. 3). Now reset the bit height to 9/16" and use a sled or miter gauge to support the parts as the dovetail slots are milled through (Fig. 4).
Normally, I would fit and insert the butterfly splines at the same time I glued up the top so I could sand them all together. In this case, because two of the splines are tall to form the chopstick rests, I decided to glue the ends to the body now and fit the splines later. Apply polyurethane glue to the cherry and moisten the bamboo with a bit of water, then clamp them together and set them aside to dry (Fig. 5).
Making the splines
To make the keys and legs, I used a butterfly spline bit. It is shaped with 14° angles on top and bottom, widening out to meet in the middle. This cuts one side of the spline in a single pass and makes the setup pretty easy. I used a height gauge to set the widest point at 9/16" and made a test cut on some scrap to set the fence.
The bit should cut the entire side of the stock, leaving a sharp edge on both top and bottom. Be careful not to cut so deep that you remove material from the top or bottom, which would make the splines too narrow. Make one pass on each side of the leg stock and the spline stock (Fig. 6).
If you don’t have a butterfly bit, you can make the spline stock using your dovetail bit. Set the top of the bit to 9/16" and again set the fence to just leave a sharp point at the bottom, then flip the part end for end and cut the other side (Fig. 7). This requires four passes instead of two, and it takes a bit of fussing to make sure that the bit cuts exactly half of the face with each pass.
Test the fit. At this point, I prefer to have the splines just a little too tight in the holes. A gapless fit is important, so I usually take the time to file the faces by hand.
Cutting the splines
With the spline stock made, it can be cut to size and fitted. The two flush splines are cut to ¾" long. Return to the table saw and zero-clearance insert. Because these parts are so small at this stage, I used a stop block and held the end in place with the tip of my push stick as I cut the splines from the blank (Fig. 8). You have plenty of stock, so cut an extra or two just in case.
The chopstick rests get a matching butterfly detail at the top. For safety, cut the top detail before cutting to length. Precut a 4" long piece, and then tilt the saw blade to 14°. Set the height to just cut halfway through, and then make two cuts (Fig. 9), flipping the piece between passes. Do this to both ends, then set your stop block to 1½" and cut a rest from each end of the part (Fig. 10). Use a clamp to keep your fingers out of harm’s way.
Pause in your spline work and check to see if the top has dried. To cut the bevels on the ends of the tray, set your table saw blade to 25° and your fence to 3/8" Cut off the bottom corner of each end (Fig. 11).
Now sand the tray smooth and begin fitting the splines. My design has the two chopstick rests at opposite corners. Since most people are right-handed, this would put the chopsticks on the right side of each diner when seated opposite each other in Japanese style. Use a fine file and shave down the splines as needed, checking the fit often (Fig. 12). If you milled your stock carefully, this should be just a few minutes’ work. Be very careful to hold the file flat on the face you are working. Rounding over an edge will show as a gap when inserted.
The splines should fit pretty snugly, but if they are too tight, they might cause the cherry end to separate from the bamboo. With the proper fit, they will keep the ends attached even if the glue joint fails. All four splines should be flush to the bottom of the tray. Use the file to then ease the sharp edges of the chopstick rests. Bevel them carefully, as rounded edges won’t match all the sharp corners and angles on the rest of the piece. Before mounting the legs, sand or scrape the tray smooth on top and bottom.
Now the leg stock you made along with the splines can be crosscut to length. Again, be very precise and make sure the pieces are exactly matched to the width of the tray. Go easy on the glue; the fit will be tight, and you may get a lot of squeeze-out. Slide the legs into the dovetail grooves and let them dry. With a proper fit, you won’t have to clamp them. After they are finished drying, use the file or a block plane and add a very small chamfer along the sharp bottom edge.
Finishing
Finishing this project could not be easier. Since food will be served on it, use a salad bowl finish. It simply wipes on with a rag. The first coat will soak right in, so don’t be shy about flooding the surfaces. Wipe off the excess and set the tray aside to dry. Follow the directions for your brand. I applied three coats, sanding between the first two with a 320-grit sponge and then using a brown paper bag between coats two and three.
As much as I enjoy building the larger, more complicated projects I normally do in my shop, these smaller, one-weekend gift-type projects always remind me of how much fun the shop can be. Package this tray with a cookbook, sushi-making kit and a set of fancy chopsticks, and it becomes a wonderful handcrafted gift for the sushi lover in your life.
Sources
Bamboo riser stock: Northwest Bamboo nwbamboo.com
Purpleheart, cherry: Woodcraft Supply woodcraft.com
Butterfly spline bit: Eagle America eagleamerica.com
14° Dovetail bit: Eagle America eagleamerica.com
Ralph Bagnall
A professional woodworker for 20 years, Ralph Bagnall builds reproduction furniture in his home shop, and has been teaching and writing about woodworking for the past several years. He lives and works in Murfreesboro, Tenn.
