Compound-angle - Mortise/Tenon - Chinese Stool

[rick bear]

During a recent trip to China I became fascinated by the hand hewn stools that you see throughout the countryside. While they are deceptively simple, the joinery is not obvious to me.

An example of two similar and imported stools that I purchased in SF's China town:

http://www.vuidesign.com/Machines/stools_DSC3604.jpg

As I slowly ascend the learning curve of using hand tools, I would like to reproduce a similar stool using some of my new tools. In particular, I now have a Ray Iles 9/16" mortise chisel. Over the weekend, I made my first two hand wrought mortise & tenon joints. The first was with straight 90 degree angles; that went well.

The second was my first attempt to create a square chair leg at about 105 degree angle to the side and 105 degree angle toward the end of the stool - see example stool photo above. Being just practice, I didn't give it too much thought. I ended-up paring the cheek of the tenon and having two gaps on each end of the joint that I filled with wedges. From the outside, it doesn't look too different than the Chinese stools. I must say it was fun using my new Lee Valley bevel-up plane to trim the wedge and end of the tenon - what a marvelous tool!

I have surveyed some of the online discussions about chair construction. Wedging is apparently a commonly used practice. At this point, I would like to start by making the tenon the proper size, i.e. smaller than the mortise, and figuring out a way to angle the mortise.

Suggestions are greatly appreciated.

I'm thinking of gluing together some angled strips of wood and then clamping the resulting template to the seat of the stool to help guide the mortise chisel. This is a through mortise, so the back side will require shifting the template on the back side of the seat to finish off the through mortise so it meets at the right location. Does this sound like a reasonable approach?

Thanks - Rick

[Jim Koepke]

I'm thinking of gluing together some angled strips of wood and then clamping the resulting template to the seat of the stool to help guide the mortise chisel. This is a through mortise, so the back side will require shifting the template on the back side of the seat to finish off the through mortise so it meets at the right location. Does this sound like a reasonable approach?

You may be over thinking your approach.

Starting with a well drawn layout on your top piece may be all you really need. Bob Smalser shows the construction of a stool using bevel gauges to align the brace and bit he is using to drill the mortises for the legs.

http://www.sawmillcreek.org/showthread.php?13090-The-Incredibly-Versatile-Sweep-Brace

It would be easy to make some gauges by just sawing up a piece of scrap as a single angle guide. Mark it for use in the future. Some if my cut offs come in handy for gluing angled joints.

If you prefer to stay with rectangular tenons, then you could drill your corners with a small drill as a guide. You could also start with a round hole and square it up.

I have made a few small saw benches that are a bit different than the method used to make your stools, but there might be something to help you in these two posts:

http://www.sawmillcreek.org/showthread.php?146777-Saw-Table-Project&p=1496504

This is the build notes on my first saw bench. I have made a lot of different saw horses before this.

This next one is just to show the difference between 5, 10 and 15° angles used on the legs.

On a different note, I was in a shop recently that carries items like this. Some of the items were made from salvaged wood and some were made from fresh cut wood and then made to look like salvaged wood or as if they were 100 years old.

If you come up with a way to make new wood look old, please pass it on.

jtk

[Jim Rimmer]

Can't offer any help. But it is amazing that when you look at something simple like those stools, they don't seem too complicated until you try to reproduce them. Please post pics of yours when youd get them done.

[Jim Koepke]

Rick,

Looking a little more at the pictures it looks like there is not a striving for perfection in these stools. The one on the left looks like the front rung is at a bit of an angle and both of them look to have gaps.

I think this adds a bit to the rustic look of these items.

jtk

[rick bear]

Jtk,

Thanks for the suggestions and examples. I may find that building a finely fitted stool will not compare to the charm of these rough hewn stools.

For fun, here is a backpack used to carry bottled water and snack food to the mountain top of a Chinese National Park (Three Gorges). Notice the backpack is handcrafted in a manner that is probably reflective of hundreds of years of tradition. It is leaning up against concrete rails made to look like hand hewn wood:

http://www.vuidesign.com/Machines/chinese_back_pack_DSC9055.jpg

China is a country going though terrific changes. I suspect the stools in the post above were from a real working farm before the big migration to the cities. Incredibly, many of the old Chinese village are still intact. This next photo shows typical mortise and tenon construction at home we visited. I'm certain the timbers were cut from the adjacent forest. Taken from a Yi village at 8,000 feet, Yunnan province:

http://www.vuidesign.com/Machines/ridge_contruct_DSC1034.jpg

- Rick

[Jim Koepke]

This next photo shows typical mortise and tenon construction at home we visited. I'm certain the timbers were cut from the adjacent forest. Taken from a Yi village at 8,000 feet, Yunnan province:

http://www.vuidesign.com/Machines/ri...ct_DSC1034.jpg

That looks a lot like the interiors of buildings I have seen in the American South West. If the part of the wall with the bright colors and carving was taken out, it could be anywhere.

All over the world, people are doing the same things to make shelter and comfort.

Thanks for sharing the images.

jtk

[Andrew Yang]

As an aside, I find it curious that so often "Asian" themed furniture (and stools in particular) are distinguished by the relatively rough appearance and joinery. It's a stark contrast to the sophisticated joinery and craftsmanship that is actually more commonly found in Asian construction and furniture. Has anyone browsed through "The Complete Japanese Joinery" for instance?

[rick bear]

Andrew,

Thanks for suggesting the book, "The Complete Japanese Joinery." Looks incredible, I took the quick Amazon tour. I'm just learning to crawl when it comes to using hand tools for mortise and tenons.

I'm impressed by the simplest common items that use joinery such as the stool I cited to the incredibly sophisticated levels that the Japanese have raised the art of joinery in their architecture.

- Rick

[Jim Koepke]

As an aside, I find it curious that so often "Asian" themed furniture (and stools in particular) are distinguished by the relatively rough appearance and joinery. It's a stark contrast to the sophisticated joinery and craftsmanship that is actually more commonly found in Asian construction and furniture. Has anyone browsed through "The Complete Japanese Joinery" for instance?

Asia is a very big place. Japan is likely eons ahead of the subsistence farmers of Pakistan when it comes to what kind of furnishings are found in the home.

China is a nation of wide cultural diversity. Until recently, many areas did not have modern day comforts like electricity.

Though it would not surprise me to find factories in China turning out stools like those pictured above and at the same time making what would be considered fine furniture. If someone will buy it, they will make it.

jtk

[Jeff Bartley]

Rick,
I can't remember what issue of Popular Woodworking it was but Bob Lang wrote a great article about a Chinese stool which featured some really cool compound joinery. And it was joinery that was easiest to just cut by hand. If I can find the issue I'll post again. I built a rendition of this stool with different overall dimensions and a carved seat.....in fact I just realized that I'm sitting on it now!
Jeff

[Jim Koepke]

Rick,
I can't remember what issue of Popular Woodworking it was but Bob Lang wrote a great article about a Chinese stool which featured some really cool compound joinery. And it was joinery that was easiest to just cut by hand. If I can find the issue I'll post again. I built a rendition of this stool with different overall dimensions and a carved seat.....in fact I just realized that I'm sitting on it now!
Jeff

Amazing, this was what first popped into my mind when I saw this thread. At PWW this morning I found the stool you mention. Search PWW for > chinese stool < and it should be right near the top.

Shop Woodworking magazine has a picture of a similar stool on the Woodworking Magazine Winter 2009 issue.

There are a couple of other items found in the search related to the three legged stool that are interesting reads.

jtk

[Rob Fisher]

Rick,
I can't remember what issue of Popular Woodworking it was but Bob Lang wrote a great article about a Chinese stool which featured some really cool compound joinery. And it was joinery that was easiest to just cut by hand. If I can find the issue I'll post again. I built a rendition of this stool with different overall dimensions and a carved seat.....in fact I just realized that I'm sitting on it now!
Jeff

Winter 2009 Woodworking Magazine I believe.

Sketchup model is here;

http://sketchup.google.com/3dwarehouse/details?mid=e18fae5fcce59dcf310af74324aae27f

[Dave Anderson NH]

Asian, and particularly Chinese furniture at the high end levels is and has been extremely sophisticated for well over a thousand years. As an example, the cabriole leg introduced to European furniture in the very late 17th century and which became a prime feature of most 18th century furniture has it origins in China. The earliest Chinese examples in their simplest forms and without the western style pad, claw and ball, or slipper foot date back as far the 12th century in China. At the 18th Century Furnituremaking Conference this past January in Williamsburg the topic was Chinese influence on furniture and the presentation by the curatorial staff and outside authorities was quite eye opening.

[Harlan Barnhart]

Ming era (1600's) Chinese woodworking was second to none. They developed some incredibly complex joinery to ensure stable joints without glue.

[rick bear]

Since hand planes, hand saws, and hand chisels are all relatively new to me, I took a three and a half hour lesson with John McCormack, woodworker extraordinaire, in San Francisco this week. Besides working on sharpening and flattening one of my Marple chisels, we spent a fair amount of time on how John would analyze and make a mortise/tenon equivalent to the one on my Chinese stool. We used cherry. The result was a tenon with a single shoulder, compound angles, and two cuts for wedges.

We ran out of time, but the mortise would be cut back about an 1/8" on each end at the top to allow for the wedges. As someone suggested in this thread, we ended up using a couple of bevel gauges to get the angles for the leg. Then proceeded with cutting the end of the tenon and using that to layout the mortise along with the bevel gauges. The end result fit quite nicely.

I'm hoping to find some time this weekend to practice making this mortise and tenon. I'll add that given my novice skills, it was a pure joy watching and learning from a true expert like John.

http://www.vuidesign.com/Machines/compound_mortise_tennon.jpg


- Rick

[john brenton]

That sounds like a "grievance". I don't think anyone thinks that Asian woodwork is primitive. Asian and middle eastern woodworking is incredible, and I don't think anyone denies that. As is mentioned here, 17th century furniture (such as the "highboy" style, which some consider the pinnacle of cabinetry), is highly influenced by Asian design.

To the OP...angles are hard to make. Chairs are hard to make. I just use a protractor and do my best.



As an aside, I find it curious that so often "Asian" themed furniture (and stools in particular) are distinguished by the relatively rough appearance and joinery. It's a stark contrast to the sophisticated joinery and craftsmanship that is actually more commonly found in Asian construction and furniture. Has anyone browsed through "The Complete Japanese Joinery" for instance?

[Jon van der Linden]

Asian, and particularly Chinese furniture at the high end levels is and has been extremely sophisticated for well over a thousand years. As an example, the cabriole leg introduced to European furniture in the very late 17th century and which became a prime feature of most 18th century furniture has it origins in China. The earliest Chinese examples in their simplest forms and without the western style pad, claw and ball, or slipper foot date back as far the 12th century in China. At the 18th Century Furnituremaking Conference this past January in Williamsburg the topic was Chinese influence on furniture and the presentation by the curatorial staff and outside authorities was quite eye opening.

Only 12th century? Minoans used a cabriole style leg around 2000 BC. Looking at the furniture of the ancient Mediterranean is a bit of an eye opener. Playing the who influenced who game that far in the past is interesting, but being able to conclusively determine influence is rare.

[Jon van der Linden]

That sounds like a "grievance". I don't think anyone thinks that Asian woodwork is primitive. Asian and middle eastern woodworking is incredible, and I don't think anyone denies that. As is mentioned here, 17th century furniture (such as the "highboy" style, which some consider the pinnacle of cabinetry), is highly influenced by Asian design.


I think you're misreading his post. It's the equivalent of saying that Ikea furniture is the most common in Europe... and then going on to draw conclusions about the furniture made for Louis XIV based on that.

[Dave Anderson NH]

Interesting Jon, I have never looked at either Mediterranean or Middle Eastern furniture since my interest is primarily 17th thru early 19th century US/Canadian furniture. I would guess that you are correct about establishing positive connections between geograhically and culturally separated civilizations. Finding the physical evidence in the form of furniture would be the easy part, finding written or pictorial documentation of trade or other connections would be much harder. Neither would be in any way an easy task though. I know you were not suggesting this, but tying Minoan to any east Asian influence other than perhaps Indian would cause major uproars among both art historians and the archeologists. Cries of heretic, heretic would be heard everywhere without a huge volume of incontroversial proof. Ah, the games of academia.

By the way, I was not suggesting that Chinese cabriole legs were the earliest ones, just that the European use of them can be directly traced to the Chinese.

[john brenton]

You're probably right, and I apologize if I jumped on him for that.


I think you're misreading his post. It's the equivalent of saying that Ikea furniture is the most common in Europe... and then going on to draw conclusions about the furniture made for Louis IV based on that.

[Jon van der Linden]

Without knowing a great deal more, I have a few general observations on the Chinese European connection. Cabriole legs on the continent are quite different with a different history than in England or the US. Based only on casual observation, I think a solid claim can be made for cabriole legs in French furniture to be related to a tradition of scrolls and volutes as legs and feet as feet and therefore being unrelated to Chinese furniture.

http://www.getty.edu/art/gettyguide/artObjectDetails?artobj=6642
Is a nice example of volutes as legs, the connection with later shapes is definitely there. Looking at the profile of the volute's leading edge, they could almost be transposed to work done 80 years later.

http://www.gutenberg.org/files/14824/14824-h/14824-h.htm#Page_22
Another example that shows the relation with volutes and plants, much earlier, from the time of Louis XIII.

What happened in Great Britain and the US is likely quite different than continental Europe, especially France. I would love to see more about the connections since that kind of thing is always interesting.

[Jon van der Linden]

Rick, if you're interested in the complications of Japanese joinery there's a blog you might be interested in:

http://thecarpentryway.blogspot.com

A lot of carpentry, some furniture, and a lot of complicated joints! I haven't read his books, but as I understand it they are a thorough explanation on how to lay out many complex constructions - his main interest is in traditional Japanese roofs, but he also incorporates the joints into furniture. Plenty of photos on the blog to show how much of it is done.

[Russell Sansom]

Rick,
To address your original question ( hints for building something like the stool )...
1) While I am a fan of the wedged tenon, the bottom of my body is not. Under some circumstances during their useful lives they can pinch. I have seen these through mortises on renaissance stools but if memory serves me, they are not wedged. A wedged fox tail tenon ( which I think is the name of the hidden version of the same thing ) is a better choice for a chair leg, but it takes some practice and skill to make. A mock-up leg and mortise will show you if you got the dimensions right without wasting an entire stool. It's enough to make a 3-sided mockup mortise so you can see inside and assemble/disassemble it until you get the wedges the right length and taper.
A draw-bore is a better choice in my opinion.
2) The splayed ( a-frame ) stool isn't too much harder than the squared-up one. Exactly the same marking out. Same number of mortises and tenons. I would suggest you complete a square one first. There are some things to learn from that exercise. If you start with square, true, well-finished components all you have to do is mark it out precisely and the thing will come out fine, a-frame or not. The only catch is that the a-frame needs the two angles, so you need a bevel gauge. Well, two. As suggested above, if you make the gauge first, you can go from there. I would discourage you from using a sliding bevel gauge unless you're positive the angle can't be budged throughout the build.
3) The "coarse" a-frame stool is another beast. A coarse one made of cylinders can come out as a quite refined piece of furniture. Witness the green wood versions and those wonderful chairs of all kinds produced by my ancestors in the Appalacians. A squareish whacked up one as pictured can be unpleasant to sit on even though the legs can easily be cut off so the thing doesn't rock. Even if you're a raw beginner, just being here on SMC puts you above this kind of work.

[David Keller NC]

Rick - A comment on "angled" mortises. It's not at all uncommon in hand work to find angled mortises when the angle is not 90 degrees to the face grain of the wood, but it is exceedingly uncommon to find mortises that are angled with respect to the long grain of the wood. In other words, one generally does not see mortises that are angled such that wood fibers are severed along the walls of the mortise, but it is common to see them where the fibers of the wood are severed at the ends of the mortise such that those ends aren't 90 degrees to the surface.

Instead, what one often finds in the compound angle of the legs of a stool or chair is that the tenon is sawn at something other than a 90 degree reference to the rail or rung when viewed from the side, but is 90 degrees to the rail or rung when viewed from the top.

The reason is relatively straightforward - because the mortise chisel doesn't really have an effective cutting edge along its back, cutting the mortise so that the chisel would be laid over on its side to some extent isn't very effective at producing a quick, clean joint. But you can lean the mortise chisel forward and back to angle the ends of the mortise. And if you're looking at an article that was produced several hundred years ago, the object was to get a decent result as quickly as possible using as few tools as possible. Producing a compound angled mortise generally requires drilling and then paring (perhaps with a compound guide block). This is pretty slow work, and one doesn't generally see it on furniture from the age of handwork.

All that said, it is fairly easy to produce a compound angled mortise with a mortising machine, so it's not at all unusual to see such construction on modern furniture, and on furniture that was produced by modern means that's intended to look like a piece from the age of handwork.

[rick bear]

David,

That's very interesting. John McCormack (SF), who taught me some ways to approach this on Wednesday did a remarkable job of cutting both the tenon and mortise, quite clean. I don't dispute what you are saying. I think the stool in question is made of Elmwood.

I did spend about three weeks in China last April (2010). One of our new friends is a young college educated woman who grew up in a small farming village (about 15 years ago, I've been told about 85% of the Chinese population still lived in villages, today the number is 50%). I sent her a detailed photo of two stools that I purchased in SF's China town ($20/stool). She said they were very similar to the ones her grandfather made. I'm now quite curious; I'll see if she can send me more information on what types of tools her grandfather used. This style of stool run from small to lengthy benches and are ubiquitous in China. Because of the massive migration of people from the villages to the cities, we may continue to see an influx of "village" furniture into the US. It appeared to me that many of the village we visited had dropped dramatically in population size.

From a quick Google of "elmwood chinese stool"

http://asianantiques-art.com/shop/chinese-furniture/chinese-elmwood-country-stools/

Thanks - Rick

[Andrew Yang]

I'm not sure if being "grieved" is good or bad in the context of the forum. Regardless, I wasn't personally offended, it was just an observation. Needless to say, Asia is a massive continent encompassing a wide array of cultures. That leads to an equally wide range of sophistication with respect to woodworking. With some of the later comments, it should be recognized that even within China there is a wide range of culture. If you consider the relative lack of homogeneity within the USA, extrapolate that to a nation with triple the population and almost 20x the recorded history.

In the end, I guess Jon said it well. It's like seeing an Ikea sidetable and assuming all European furniture is of similar form and construction.

More to the topic, the stool in Woodworking Magazine did look very cool in the article. It was equally so in real life. There were a couple samples of it in the Popular Woodworking offices last weekend. If I recall the article, the emphasis was on full size layout, and locking down your bevel gauge.

[Jon van der Linden]

The full size layout is an interesting point that Andrew brings up. My understanding is that for some complex joints Japanese traditionally do layout drawings at an enlarged size specifically for angle transfer. Whether they actually do it or not is moot, if you're setting an angle from a drawing, bigger is better!

[Andrew Yang]

I happened to have the pdf here, and took another look at the issue. It's from the Winter 2009 issue. Looking at the issue, it also occurred to me that Bob made a few iterations of the stretchers, as they were hanging over his workbench in the shop. He definitely is a proponent of a full size layout drawing to make sure the angles are correct. However, he does his on a piece of scrap plywood, and uses it to measure off his angles and lengths. I'm sure Bob would be more than happy to answer questions if people are interested in building the stool.