The Japanese Floor Workbench (Atedai 当て台) by Dominic Campbell – Part 1

The Shokunin’s art is difficult, if not impossible, to separate from his work space, his tools and his equipment. The craft is not apart from his life so much as it is a heightened detail of life.”

Toshio Odate

Foreward

Today’s article is a guest post by Mr. Dominic Campbell, a friend and deeply Beloved Customer residing in Old Blighty who, when he needed a workbench, decided to make a traditional Japanese atedai, a solution I too am very fond of, even if my knees aren’t anymore.

This is the first in a two part series about his atedai Dom was kind enough to share with us. This first part is about the design and construction of the atedai in question. The second part will be about how to use this excellent tool. Enjoy!

Stan Covington

Introduction 

I began woodworking, I guess, like a lot of the readers of this blog, with some hand-me-down western tools, and a pair of cheap, flimsy, store-bought sawhorses. A lack of space, the inclement British weather and my lack of any form of work holding made sawing and other simple tasks difficult and frustrating.

I then stumbled across a video of a Japanese craftsman working in a very similar manner, yet with far superior results… I had to know what this guy knew. While reading, practicing, and absorbing as much information as I could ( some would say falling down the Japanese woodworking rabbit hole), my work developed, and I built up my skills to a point where I felt the need for a dedicated workbench. Using Japanese tools for 95% of my work, I have found they work best as part of a system, and so decided on a Japanese floor workbench AKA an Atedai (ah/teh/dai 当て台). This kind of workbench lends itself to a very flexible workspace. It can be adapted to use standing up, and easily stored out of the way conserving space when necessary, an important part of the Japanese tradition.

Much of my own work is kurimono (刳物), or carving from solid blocks of wood, as well as a bit of sashimono casework (指物) and tategu joinery work (建具), including kumiko-zaiku (組子細工). I tried to make one bench that would work for all of these specialties, but with an emphasis on the heavy chisel work needed in kurimono. 

After keeping Stan up to date with my progress on the workbench build, and showing him what his tools had been up to, he asked if I wanted to share my thoughts on this style of workbench.

And so, in this mini-series, I hope to show you, Gentle Reader, a method of working, and work holding that may, or may not, be of immediate practical use to you, but that is interesting, and provides some food for thought, nonetheless.

Atedai Construction

Before we look at how to use an Atedai, we first need to build one, and although the construction of the Atedai is simple at first glance, there are a few important considerations and details to keep in mind.

It must also be said here that all workbenches are as varied as the people that use them, and this is no different for the Atedai. The type of work you do, the materials you work with, the training received, how tall you are, how you intend to use it… the list is endless…will all dictate your bench’s dimensions, design details and final appearance. It is not uncommon for craftsmen to have several atedai on-hand depending on the task undertaken. In this post I will focus on just a single way to get the job done.

The Work Surface

The work surface is the heart of any workbench, and it is no different here. We mostly have the same considerations too: single slab, or laminated? What species of wood? How long? How wide? How thick? What height? Will it be flat or angled? There are no right or wrong answers, within reason, and is often a case, the final selection will depend on what you can get hold of, what you like, and the type of work that you do (you can start to see why craftsmen often have a number of benches in their workshops – they are easy enough to make, and store easily out of the way, taking little space, so why not?).

My own bench top is a 57″ x 17″ x 3.5″ sycamore slab (and 7″ high with the legs in). This is quite long for the work I do, but it gives the bench good weight/inertia, and is useful for the occasional long beam I have to work. It was not, however, easy to get flat, nor is it easy to keep dead flat along its entire length and width. You pays your money and you takes your chances…

A Few Observations

There are a number of possible answers to the questions posed in the previous section, and so I thought it would be useful to briefly explain my thoughts behind the selection and preparation of my work surface in order to give some insight into the kinds of questions you should be thinking of.

With regard to construction, you have to weigh the pros and cons of each approach, and make a decision that works for you. A laminated top will tend to be a bit more stable, whereas a solid top could be liable to warping a bit more. A solid slab is a bit more traditional, can be made to move a bit less through certain techniques (as we’ll see below), and is quick and easy to put together – i.e. you buy it, and apart from surface prep, the top is basically done. That said, big slabs can be harder to find (depending on where you are), and can be expensive. I actually found it easier to find a slab, than it was to find smaller stock of the same woods…. most lumber yards near me won’t give small orders the time of day… it was either construction pine, or a big hardwood slab. I hope you have better options!

In terms of wood choice, most woods commonly used to make workbenches will work fine. Too soft and the atedai will be easily damaged, but too hard and the atedai may damage your work (especially if using softer woods), and become slippery. Woods with contrasting hardness between winter/summer growth like douglas fir can work, but problems can arise especially if you shoot a lot on the surface, as the winter wood and summer wood can wear down at different rates leaving ridges. I went with Sycamore (Acer pseudoplatanus – actually a kind of maple) as it has a fine grain, is medium hardness, and I could get hold of it in the right dimensions for less than £100… all important considerations!

To make sure my top was as acclimatized as possible, I left it for about 5-6 months in the workshop where it will be used (it was air dry when I bought it, but I don’t know for how long). My shop is an unheated 1 car garage, and not climate controlled (I use a small dehumidifier, however), so I expect some movement. That said, I wanted to give it the best chance of settling in before I started flattening the top, and doing the joinery for the stops and legs.

When I brought the slab home it had quite a bit of cup and twist – one potential downside of using big slabs – and it took some hard yards to make it flat and twist free. I left the underside untouched as much as possible – to retain as much weight as I could in the bench – planing only where the legs would go, plus a bit on either side. Preparing a big slab, unless you have an industrial sized planer, is a hand tool job, so prepare yourself for a work out.

The sides of my bench are 90° to the top, with special attention placed on the right hand side when sitting at the working end. This is traditional with atedai because the user indexes a plane vertically against the right hand edge of the top to quickly shoot the edge of boards to 90° , although I prefer to use shooting jigs to help when 100% precision is needed. You can also attach a length of wood to the right hand edge to form a support ledge for the plane when shooting.

As you can see in the pictures, this slab has a few knots scattered about, which I stabilized with CA glue, and planed flush. This has worked well so far, but if the knots come loose in the future, I will cut them out and patch them.

With regard to dimensions, the general rule of thumb is that if you work wider boards you tend to need a wider bench (although you can up to a point plane wide boards on the narrow bench, it can be hard to use the bench as a reference surface to check for twist). However, too wide is harder to keep flat, is heavy, and is more expensive. 

Too short a bench makes it harder, if not impossible, to plane longer stock. But again, too long is heavy, expensive, and harder to keep flat (can you see a trend here?). It is also impractical, unless you are Stretch Armstrong, as you can only plane as far as you can reach while sitting or kneeling. That said, you can (as you will see in Part 2) put a floor bench on saw horses (or your normal workbench) to use standing up to increase your reach, in which case a longer bench can help cover long stock prep too.

The final question regarding dimensions is total height, a combination of top thickness plus the legs. Most people use an atedai while sitting on a zabuton cushion placed on the floor like the one shown in the photo above. In this case, the bench top should be low enough to hit your knee so you can stop it from sliding, but high enough that your plane will not hit your knee (ouch!) when planing or shooting down the middle of the stops. Somewhere between 4-7 inches high normally works well, with a slab thickness of between 2-4+ inches, YMMV. If in doubt, go higher – you can always reduce the height slightly later down the road. And zabutons tend to become thinner with use.

Another consideration is perhaps unique to the Japanese atedai, namely whether or not to build the top with a slope. Some craftsmen prefer the bench to slope down towards the end they sit at for ease of planing, but I prefer a flat surface. It’s a better all-rounder, and it’s easy enough to prop up the far end temporarily if desired.

To slow down any movement, I sealed all end grain surfaces (using Osmo End Grain sealer) on the completed workbench (top, legs, and stops). All of this combined (plus dovetailing the legs, as explained below) has worked well to stabilize the top, and movement has been minimal, although it’s always worth checking before any fine joinery task… little and often is a good idea for keeping a bench flat. 

The end grain sealing is all the finish I have applied to this bench. I left the top with the planed surface in order to keep it from becoming too slick. As I don’t use a lot of glue or finishes in my work, I didn’t apply anything else to the surface, but a light coat of oil can help things from sticking too much if needed.

The Legs

Now back to the construction of the atedai, we come to the legs, or battens, which should be thick and solid – in my case 4×4 inch sycamore attached to the underside of the top with sliding dovetails.

You can simply toe-nail, or similar, the legs in place if you wish, but the sliding dovetail helps to keep the board flat and is, IMHO, a much more elegant, long term, solution. It is not uncommon in Japan for these benches to be passed down from master to apprentice, so I built mine too with longevity in mind. Sliding dovetails can also help knock the bench down for storage or transport, if that is something that you will need.

After talking to Stan, I went with a double tapered sliding dovetail, which helps the legs fit extremely tightly (while also being much easier to slide in place), and helps resist humidity fluctuations, bangs and vibrations better than a standard tapered sliding dovetail – all important advantages for a workbench. 

The double taper in this case refers to a taper not just in the width of the dovetail (as is fairly common) but also in the height of the groove along its length, with the leg tapered to match. This connection can be achieved in any number of ways, in my case with plane and kotenomi. The tapers on my bench were around 1cm in width, across the board, and 0.5cm in height – this still made for a pretty tight fit.

My legs right now are just a bit proud of the edge of the top while it settles in, so I can knock them in further later if needed. Their slight projection doesn’t interfere with shooting with a top that is 3+ inches thick however, so they aren’t causing any headaches being a little proud…

As a final touch on the legs, and to give the bench the most stable footing possible, it is wise to relieve the middle of the legs slightly – just enough to keep it clear of the floor. Also, some thin rubber, cork, or in my case, part of an old chisel roll, help to prevent the bench from sliding around. You don’t want to use anything too thick however, as that will absorb too much shock, reducing the efficiency of your hammer blows when chiseling.

The Stop(s)

The work you do will determine what kind of stops you need. Sashimono-shi tend to use much thinner stops, while those using the bench for kurimono, or hollowing work, will often (but not always) use more substantial stops to stand up to the forces involved, often with just one stop across the entire width of the board. Again, it’s horses for courses.

Back then, to our good old friend the sliding dovetail. In my case for the stops, I used a regular stopped sliding dovetail. I didn’t taper the stops at all, as I wanted to make sure they stay in place firmly – a sideways knock on a tapered stop will send it flying too easily for my liking.

My stops are quite substantial, much bigger than I have seen sashimono-shi use, but stop short of a full width stop, in order to leave room for morticing longer stock (see part 2, coming soon, for the venerable bum clamp), as well as a gap for shooting. If you decide to make your own atedai, you will need to consider what work you will use it for, and plan your stops accordingly.

One useful feature of the stops is that being dovetailed, you can make several and interchange them, or remove them completely, depending on what you are doing. These benches really are incredibly versatile, and are completely custom to the work you do – a joy to use.

Summary

And there you have it. Four sliding dovetails cut into a slab of wood to receive two short legs and two stops and you have yourself a workbench that is quickly ready to go to work but easily stored away in a few seconds when not needed.

I hope, in this post, to have given you some insight into how to build an atedai workbench for yourself, and some of the considerations you must think about if you do. They are simple benches, but there are a few important considerations to think about before you decide to make one. If you have any questions, just leave a comment below, and Stan or I will do our best to help.

In Part 2 of this mini-series I will show you how you can actually go about using such a workbench, some further customizations that one can make, and some examples from other craftsmen to help inspire you – I hope you’ll join us. 

Yours in wood,

Dominic Campbell, Kent, UK

Other Posts in This Series

The Japanese Floor Workbench (Atedai 当て台) by Dominic Campbell – Part 2