Kumiko being the Japanese woodworking art of expression, can be very appealing for people. Creating it though is another story altogether, as it looks to be very simple but is rather complicated. But with the right tools and setup, you can create somewhat simpler designs with ease. In this article, we will give you the step-by-step guide to crafting your own Kumiko.
To make a Kumiko, you first need to cut slots into an equal piece of wood, the size is up to you. This will serve as the base of the design in which you will slide into smaller pieces. For the smaller pieces to fit together you need to design a jig that helps trim their edges into different angles. Once you make the jig, you can just slide the pieces together in order.
Japanese woodworking is famous for not using nails, metal fasteners, screws, or adhesives to join wood. While made out of necessity in the past, in the present it is considered a pinnacle of woodworking techniques. People take years to master all of them, Kumiko is one such technique in Japanese woodworking.
While there are many designs of Kumiko in Japanese woodworking, one of the most famous is Asa Noha. This is the one which we will be working on in this guide since it is very popular throughout the globe. The Asa Noha design represents the hemp leaf, which in Japanese culture represents growth. Not only that, the Japanese have incorporated the pattern into their textile as well.
Steps to Craft a Kumiko
Before we dive right into the steps that will lead you to create your very first Kumiko, you need to have the tools to make it. While you can use the tools which are already present in your workshop, some tools you might want to consider buying to help ease your task.
Tools to Help Make Kumiko
While you can make Kumiko with the tools you might already have, to help make the job easier you will need the right tools. A set of Japanese chisels is not important but highly recommended if you plan on making the Kumiko by hand. This will help you make the slot in wood if you don’t own a table saw. Though you can also use western chisels for the task as well, Japanese woodworking will be much easier with Japanese tools.
You will need a Ryoba, this one from SUIZAN is a great addition to any woodworker’s arsenal. Another tool you will need is a mini hand planer, this one by Yogeon can be useful to plane down the strips to perfect thickness and to plane the edges. Lastly, what we will need is a marking gauge and Kakuri is a famous brand that makes such cutting gauges for Japanese woodworking.
Designing a Jig
This is the most important step that will help you angle the strips that are in the Asa Noha pattern. These strips need to be angled at their edges so that when put together they slide in the corners and fit. To design this jig you will need a block of wood, it has to be at least 2-3 inches thick and 3-4 inches tall with a length of 10-15 inches.
You have plenty of leeway in the dimensions, but one thing you have to be sure of is that all the sides of the block are perfectly flat. Once it is perfectly flat and all the sides are 90-degree with the adjacent sides, we can start to cut the angles.
The first angle that you need to cut the corners in length is 45-degrees. Once you cut it, plane it off with a mini planer to make it straight, and then check the angle to make sure it is perfect.
You will need to repeat the process with the other three corners as well. Two of the opposite corners need to be at 65.5-degrees, and one corner needs to be at 22.5-degrees. Plane them down and measure them to make sure they are at the right angle.
Once that is done, you need to create grooves on the top side of the block that runs into the angular cut. These grooves need to be as thick as the Kumiko strips, to cut the grooves you can either use a chisel to carve it out by hand or you can use a power tool.
Right between the groove, you need to insert a screw thread that will be used as a stopper. You can use a slotted strip the size of the groove that allows the stopper to be mobile.
The slotted strip slides back and forth according to the length of the strips you are using in the Kumiko project. The screw can be tightened where the slotted strip needs to be tightened. Do this on both sides and your jig is ready to be used for your Kumiko.
Here is a video guide of how you can make the jig for a visual understanding:
Step 1 – Slotting the Base Strips
The base strips are going to be the foundation on which the whole design is going to sit. This can be longer than what you want in mind and can later be trimmer or cut down with a Ryoba.
First cut the strips down and mark them exactly at the same place in all strips where they need to be joined together.
Slot them using a chisel half their width and then join them together in a way it looks like a four-pane window. Just double the strips on the four corners for more stability.
Step 2 – Cutting Down the 45-Degree Strip
Now you need to cut down the strips that will slide in these four window panes. This is where we make the Asa Noha pattern for this Kumiko project. Mark one strip of wood by placing it diagonal inside one of the four empty panes.
Cut it a bit longer so that when you carve the angle you don’t shorten it too much. This one will be carved 45-degrees at the edges. Now try to fit the strip of wood into the pane and see if it sits just right. If it is loose, you need to re-do it with another strip to ensure it sits just right and does not slide out easily.
Repeat this process 4 times to fill in all four of the empty panes until they fit diagonally from the centre where the base intersects to the diagonal corners.
Step 3 – Cutting Down the Splay in Strips
To carve the splay in strips, the ones that will fit inside you need to cut them into smaller strips that will meet from the diagonal strip right to the middle where they intersect at their angular edges.
First, you need to angle them at 22.5 degrees at one end and 67.5 at the other end. They will need to sit right in the corner and meet at the angle just right.
They shouldn’t be a loose fit and should slide together perfectly. You need to make 16 of these to fill in the whole pattern.
Step 4 – Working the Last Fittings
These strips will fit the stips that are meeting at the 22.5-degree angle. When both of those meet they will leave a 45 by 45-degree angular space between them.
Which is what you must do with the final fittings. Use your jig to make the edge of these final fittings into a 45 by 45-degree bevel like that of a wedge.
Once that is done, slide it into the open space between the splay in strips while the other corner should slide right into the diagonal corner of the base.
With this, your Kumiko pattern should be done, though it might require a few tries to get it perfect. But once all the strips sit together snug and fit, they will not move and will not require any other support other than the angles they push each other at.
Here is a video that illustrates the whole step-by-step process above for a more visual representation.
Kumiko Hand Tools
Above we spoke briefly about what tools are required to make a Kumiko pattern. Let us speak about these tools in more detail to understand their importance and use.
A Japanese hand saw that cuts in pull motion rather than the push motion in normal ones. It is extremely thin, so the kerf size is rather small making it much easier to rip smaller boards out of wood. This can be used to cut the strips that are used in Kumiko by measurement. A Ryoba is a handy tool to have around and this SUIZAN Ryoba allows you to change blades once they are worn out.
2. Wood Marking Gauge
A Japanese wood marking gauge or cutting gauge known as Kebiki is also a great tool to have handy. Rather than digging in points in the wood, this Kebiki will cut lines into it giving the Ryoba a pilot to work. These come with a knife or blade insert and have a very wide stock to give you the freedom to mark with ease. This Kakuri Wood Marking Gauge is highly recommended if you want to buy one for your shop.
3. Mini Hand Plane
A mini hand plane can access areas normal hand planes cannot due to their size. For shaving down the strips of our Kumiko, a mini hand plane will be very helpful. It can also help you trim down the edges of the strips at various angles in the jig we will design. This Yogeon Mini Hand Planer will serve well for this purpose or any other and add as a great collection to your woodworking tools.
4. Nomi or Japanese Chisels
It is not important to use Japanese Nomi or chisels, as you can also use western-styled chisels for the job. But having authentic Japanese chisels will give you a much better understanding of how the Kumiki was made with these tools in mind.
Tips for Creating Kumiko for the First Time
- Patience is key, do not overdo it, take your time, measure each strip twice when cutting and carving the angle on these sticks. This way you can save precious resources and time to redo it if you end up making a mistake.
- Make sure all the pieces are the same thickness as the other. Use the thickness of the slot or groove in the jig to shave every strip to the same size.
- Use your Ryoba to cut thin strips from a bigger block as it does a great job of cutting off thin strips. The thinner blade does not remove too much material when cutting.
- Make sure to get the angles of the strips right otherwise they will not fit in. Keep fitting the pieces into the frame to see if the angles are a perfect fit or not.
- The marking gauge of Kebiki does a great job at creating the initial cuts into the wood for your Ryoba, use that to your advantage.
There are many kinds of Kumiko patterns, but if you master this one, you will understand the fundamentals of how to work on the others as well. The Asa Noha is a beautiful pattern and mastering it does not require a lot of time. With the right tools and a jig to help cut the edges at an angle, you will be able to make your Kumiko project in no time.