Building the Shoji Doors
Here follows a detailed description of the process I used to make a set of shoji doors. While many of the shoji doors in this project had different over all dimensions, the joinery dimensions were all similar, the main differences being piece total length and spacing of the kumiko mortises in the rails and stiles.
Keeping track of everything was important so as to not get the sets of parts confused, but also letting me use repeated operations to make the build process more efficient. To that end I printed out small mailing labels with part information. These were always installed on the front face of each part and the text position indicated what was the top, bottom, left and right.
The essential assembly steps of these shoji doors can be broken down as follows:
- Preparation of the lower hip boards.
- Preparation of the rails and stiles.
- Preparation of the kumiko grid.
- Frame final planing, assembly and detailing.
- Installation of the shoji paper.
Preparing the Hip Boards
The hip board material was a very fine, straight grain piece of Douglas Fir. My goal was to mill this material to maximize the clean vertical grain of my panels. In retrospect I should have just sourced vertical grain boards, rather than engage in the following, convoluted process. But hey, grain matters.
I first milled the one large board into a set of squared up blocks, labeling the grain orientation:
Then I set an angle on my bandsaw table such that I could cut several sections out of these blocks effectively making rift-sawn boards with perfectly vertical and evenly spaced grain. You can see in the picture below the wasted, "wedges" that were left over after the milling process:
Finally, each of these boards were jointed and planned to an even thickness with square edges in preparation for the panel glue ups. During jointing, increased pressure halfway through the run results in a slight arch along the edge. When two boards are clamped together the compression ensures the ends of the seams do not separate. This technique is further detailed in Toshio Odate's book, "Making Shoji."
Prior to panel glue up I arranged each of the boards so I could mix and match the stock to create both the size of panels needed as well as ensure aesthetically pleasing grain orientation and color matching. Additionally, I can arrange the boards in such a way, that I'll only be required to plane in one direction for finishing.
Again using techniques from Odate's book I adapted the rope/clamp/batten set up by making a jig to hold long pipe clamps with clearance for two sets of arched cols. Thus I can compress all the panels against the glue edges while at the same time using the cauls to keep the panels flat and lined up. Note that the surfaces of the cols are faced with HDPE plastic sheeting which won't stick to wood glue.
After all the panels were dry, I was lucky to get access to a wide belt sander to take them all down to final thickness quickly. Then I only needed to take a few light finish strokes with a plane to complete the surfaces.
Preparing Frame Rails and Stiles
The frames of these shoji are made of buttery, creamy, wonderful vertical grain Alaskan Yellow Cedar. I began by cutting my stock into rough lengths and designating which parts will come from each part.
I jointed and planed the stock and then marked the ends with an identification number and lines to indicate grain progression and where the inside or outside of the tree seemed to be (I'm still getting the hang of this.) These concerns are important so that the shoji frame ages and moves correctly. All wood moves with time and I want my frame members to bend inward, tightening against the kumiko grid.
Next came rough ripping each of the components out of the prepared stock, and jointing or planing as necessary to make the final dimensions. These pieces are ever so slightly oversized to account for final finish planing.
Now I could layout all the joinery, each of the rails has a haunched tenon featuring a reverse chamfer (jaguchi) on one side, and the stiles have 3 mortises plus the small mortises for the kumiko grid. Four of the doors featured exposed wedged tenons on the visible edges. While not strictly traditional, showing the joinery was a detail the client desired.
For efficiency reasons my "modern" traditional woodworking process typically follows a layout, power tool, hand tool progression. I try to do the bulk of the dirty work with repeatable power tools and jigs before finishing with hand tools. After layout I used my mortise machine to remove the bulk of the material from all the stile mortises. Very careful set up and a sharp 1/4" plunge mortise chisel allowed me to create the finished kumiko mortises in a single operation.
To create a crisp jaguchi reverse chamfer on the shoulders of all the rails I very carefully set up a table saw operation to cut the angled component. This angled area will but up against the chamfers cut on the inside edges of the rails and stiles. After cutting this part of the shoulder I also roughed out the rest of the shoulders on the table saw.
And using a home-made tenon jig, and a flat tooth joinery blade I cut all of the cheeks:
Below you can see the test joint for the jaguchi tenon mating against a full length chamfer on the sample stile.
There were a few places I did not use this joint. The inside edges of the back of the door frame are not heavily chamfered because the kumiko grid butts right up against the frame forming an even plane to which the paper attaches. So for the rear of the top rail, I simply trimmed that shoulder flush with a chisel and guide block:
Whereas in for the rear of the middle rails I used a different guide block to chamfer a portion of the shoulder that embeds into the stile. This way on the upper edge I can leave off the chamfer because that is where the paper will attach, but on the lower edge an can chamfer it to cleanly meet the chamfer on the stile where the hip board goes:
Here we have all the trimmed and fitted tenons:
The final operations on the frame members were cutting grooves to accept the hip boards. This was more straight forward on the bottom and middle rail: a quick pass through a dado blade. On the lower portions of the stiles, however, I had to set up a fixture and use my groover saw to cut stopped dados only until the mortise for the middle stile:
Then I hogged out a small mortise for the cherry door handle to be fitted later:
Lastly, I spent a wonderful session hand planing each component to a high sheen and chamfering the necessary edges. At last all the frame components were complete:
Preparing the Kumiko Grid
Preparing the kumiko strips for the grid deserves its own article, fortunately I wrote about that process as well as the making of a special plane (hikouki kanna) to finish them.
Preparing the strips required ripping the material to size then finish planing them to an exact thickness. To ensure the layout and spacing of the grid was exact, during layout I clammed the relevant rails or stiles on either side of the set of kumiko strips and transferred my marks across all the pieces. Now the mortises would be exactly in line with the half-lap joints in the kumiko.
I cut each of the half laps with my table saw sled, erring on the side of too tight, so I could compression fit the joints. The end tenons were cut, cleaned and chamfered on all edges:
Then it was a simple matter of slightly hammering the mating edges of the half-lap joints to compress the fibers and assembling each grid:
Assembly and Details
Before final assembly I fitted each of the cherry handles on each side of the stiles. This was a matter of ever so slightly trimming the rough mortise to accept the lightly tapered handle. When I hammered the handle in, it compressed against the mortise edge giving a tight, clean fit.
Two of the doors were for the entrance to a prayer room, so for a little extra pop I inlayed a star and crescent moon of ebony into the inside edges that would only be seen when the doors are open:
Not pictured was the laborious, but necessary process of test fitting all of the joints prior to assembly. I wanted to ensure all of the joinery fit very tightly with no gaps as well as have planar surfaces line up. After this I fitted the grid and hip board into the rails and glued and clamped the stiles onto them:
For those doors that featured exposed wedged tenons, after the glue had set I trimmed the excess and affixing the whole door to a improvised planing bench I took a few passes to unify the exposed edge:
With all the doors assembled, all that remained was attaching the shoji paper:
Of the seven doors I built 3 used a resilient laminated shoji paper as these were in and around the moist bathroom and laundry area of the house. The other four, two for the entrance and two for the prayer room used an authentic kozo paper which really looks stunning in the light.
For these doors I used a shoji specific double sided tape on all of the grid and border, starting from one edge and smoothing the paper to the other side. After a rough trim I used a well sharpened marking gauge to trim the paper to final dimension on the shoji:
It was a humbling experience to make these doors. Of all the lessons I learned the most important would be to spare no time and attention on layout and organization of your process. Attention to detail at this early stage paid me back many fold with tightly fitting joinery and pleasing grain arrangement.
These doors were installed in the Econest home for which I also made the tokonoma and mandala ceiling. In this home the doors were intended to slide on recessed hanging rails rather than the traditional grooves in the floor.
Install was a quick, I attached the hardware to the top of each door, slide the doors onto their mating carriages and adjusted the leveling screws to get the doors to sit plumb:
The addition of these shoji doors truly completed this home calmly filtered the light into the main living room.