Anyone tried this: Peening your tenons

[Frederick Skelly]

Current FWW has a full page shop tip on doing this (FWW #263, page 12). Basically, you cut a snug tenon, pound the tenon's faces gently to compress them and then put glue on it and slip it into the mortise. The author said it's a Japanese technique.

Thoughts?
Fred

[Jim Koepke]

For a moment my response was going to be about how Chris Schwarz did something like this to help fill gaps in dovetails.

The technique you mention is more akin to planishing than peening. Both are metal working terms that are making their way in to woodworking

jtk

[Brian Holcombe]

Very commonly practiced in boat building amongst other things.

[Malcolm Schweizer]

Am I the only one that at first thought this said "Peeing in your tenons"? I thought, "Okay, I'm all for unplugged, but that's taking it a bit too far." Dyslexia can be funny sometimes.

[lowell holmes]

I would be more likely to plane translucent shavings until the tenon fit.

[Pat Barry]

I think the idea behind this is to get a tighter fit after the temporary wood fiber compression from the peening takes place. The moisture in the glue will expedite this (like biscuits swelling up).

[Brian Holcombe]

The point is not to make the tenon fit, it is to compress the tenon so that when it swells back up it locks the assembly together. Don't go overboard and it works fine.

Pat beat me to it*

[Simon MacGowen]

Such a method is ok for anyone who has yet to develop his or her hand skills. Or someone who is mainly a power tool user. It is not something I will do or recommend to anyone who is seriously interested in developing traditional skills. Same thing I cringe when I see someone use a file to fine tune a mortise & tenon joint or even a dovetail (oh yes, I have seen that in magazine articles).

As a top tip winner, it does not have a place in a publication like FWW. Fine if I saw it in Woodsmith or something like that. May be next time someone would win a top prize from FWW by suggesting using a sledge hammer instead of a plane to remove a high spot on a board.

By the way, don't know if it is indeed a Japanese technique but I have seen anything like that in any publications or videos. Everything I have seen by Japanese woodworkers is fine tuning with a chisel or plane.

Simon

[Warren Weckesser]

Skip to about 4:35 to see an example of this applied to butterfly keys: https://www.youtube.com/watch?v=x51zMg7roIs&t=310s

[Simon MacGowen]

Thanks for the link. I have seen hammering in other contexts (by non-Japanese woodworkers) but not the compressing in a vise. When I do wedging (mortise & tenon), I sometimes hammer the wedges (sides or tip) for a supertight fit.

Simon

[Brian Holcombe]

Who is crimping them in a vise? Again this is a common technique, often applied to softwoods, I believe it does a disservice to hardwoods.

[Scott Pearson]

I have read that it used in Japanese joinery with a Japanese hammer. The purpose is to compress the tenon to fit the mortise snugly and then allow the tenon to swell from the moisture of the glue for a tighter fit. The reason for the Japanese hammer is that one face of the hammer is 'crowned' not round like a ball peen. The crown compresses the wood without cutting the fibers. A flat faced hammer will cut the fibers of the wood and stop or reduce the wood fibers from swelling. A ball peen hammer would just create divots and dents and would not spread over the whole face of the tenon.

I have not used this technique so I have no experience but it seems like it could be a workable technique to get a solid tenon.

Scott

[Simon MacGowen]

Who is crimping them in a vise? Again this is a common technique, often applied to softwoods, I believe it does a disservice to hardwoods.

Are we talking about the same tip?

In the second illustration with this caption: "Use a vise to compress..."

My objection to the tip -- whether it is a Japanese technique or not -- is that FWW should promote it as a tip but not as the Best Tip. If one has no access to a fine shoulder plane or chisel or a router (Paul Sellers' preferred approach), that is a way of finetuning a mortise and tenon joint. But to anyone looking to develop fine traditional skills, I will steer them away from it, and would never look at it as a best tip.

Simon

[Brian Holcombe]

Don't use it then, but it's not being used becuase the user doesn't know any better, it's being applied in a purposeful manner when done correctly.

It is a traditional technique in fact I had been studying Japanese bathtubs recently and the technique is applied very purposefully to their construction. They don't need to caulk the joints becuase of this.

[Simon MacGowen]

Not meant to be putting down any techniques of any other cultures (we all can learn from each other) with my objection and I use Japanese saws and chisels when the occasions call for them.

Not very tip I see in FWW or any other magazines is adopted or used unreservedly in my shop. Some are lousy ideas for me though they may be smart solutions for others (including the Editors who publish them). Like anything else, we each have to decide for ourselves our ways of doing things. I, for one, rarely use softwood, but even if I use it, the vise in my shop or a file will not be put to use for fine tuning any joint.

Simon

[david charlesworth]

I take it this is a different technique to "Bishoping" pins?

This involves hammering protruding pins to try and get a better fit.......... a very crude method, frowned upon I think.

David Charlesworth

[Simon MacGowen]

I take it this is a different technique to "Bishoping" pins?

This involves hammering protruding pins to try and get a better fit.......... a very crude method, frowned upon I think.

David Charlesworth

A little different in the tip in that the vise is also needed and used in the second step. Hamming alone does not cut it according to the method presented in the tip.

Simon

[Graham Haydon]

David, I wonder if that's where the term "Bashing the Bishop" came from :D

[Brian Holcombe]

Not keen on the use of a vise, that seems weird and will put your references off and they note using the flat side of the hammer, which to my understanding is incorrect. One should use the rounded side of the hammer.

Also, not many Japanese shops use a vise as far as I'm aware.

This is nothing like bishoping pins, which I agree is not the way to go since it is damaging the pins.

Not sure why there is so much fixating on the 'tuning' the joint, when this technique is applied correctly the tenon is purposefully made oversize and then peened down to fit with the expectation that it will decompress slightly and lock the joint together.

This technique was discussed at length over the weekend at Kez by Douglas Brooks who mentioned boatbuilders using it extensively, some of these boat builders have been woodworking for 60+ years and many of them are top in their field. Also...their boats dont leak.

[Simon MacGowen]

Not keen on the use of a vise, that seems weird and will put your references off and they note using the flat side of the hammer, which to my understanding is incorrect. One should use the rounded side of the hammer.

Rounded side which also requires less pounding force but more accuracy relative to the flat side-- 100% agreed.

Simon

[Pat Barry]

A little different in the tip in that the vise is also needed and used in the second step. Hamming alone does not cut it according to the method presented in the tip.

Simon
I can imagine that the ends of the tenon are squeezed slightly in the vise to the same effect as the hammering of the faces. Obviously much easier to hammer the larger faces. To Brian's point, either or both of these techniques might affect your references. Did they provide a dimension reduction target in the FWW article?

[Simon MacGowen]

I can imagine that the ends of the tenon are squeezed slightly in the vise to the same effect as the hammering of the faces. Obviously much easier to hammer the larger faces. To Brian's point, either or both of these techniques might affect your references. Did they provide a dimension reduction target in the FWW article?

The vise is not used to pinch the ends but to compress the area near the shoulder where the hammering cannot reach. The author also warns against hitting the shoulder (easier said than done, sometimes).

That is also why it is not a crude method or tip I would use or endorse when other cleaner and better ways to do the same thing are available. In a few strokes with a shoulder plane, I can do what this "best tip" will do. I am constantly learning but this isn't something I will try.

Simon

[Brian Holcombe]

I did not see a target for reduction in FWW, but in other avenues of study I have read 1mm as the recommended amount.

Again, removing material and compression material are not the same thing and done with a different purpose in mind.

[Roger Nair]

I can see the advantage in terms of boat builders and tub makers by producing a self caulking wood to wood seams, however, wood that is compressed and dimples is damaged with cell wall collapse. Time, moisture and glue will not reconstitute cell walls, so I would advise caution. Why add glue to a weaken surface? Why not use a toothed plane or a scraper body with jigsaw blade?

[Brian Holcombe]

The message I'm attempting to convey is that one size does not fit all. Use it when appropriate, don't use it when inappropriate.

[Simon MacGowen]

In case I wasn't clear enough. I am not against the tip per se or its author. People can do whatever they like. People should be encouraged to create or develop new, better ways of doing things. I have used mortise and tenon alot -- cut by hand, cut with a dado cutter or with a router, floating type and even dominos. I have tried all of them. Not one single joint fit using the usual approaches has failed.

What I disagree with is Fine Woodworking thinking it is the best method as a tip ("Best Tip"). It is a tip, yes, even a good one to some. But the best tip? Is that the way to promote fine woodworking? I don't think so. But as someone has commented elsewhere, the quality of FWW has been slipping over the years -- more in recent ones.

Simon

[Pat Barry]

In case I wasn't clear enough. I am not against the tip per se or its author. People can do whatever they like. People should be encouraged to create or develop new, better ways of doing things. I have used mortise and tenon alot -- cut by hand, cut with a dado cutter or with a router, floating type and even dominos. I have tried all of them. Not one single joint fit using the usual approaches has failed.

What I disagree with is Fine Woodworking thinking it is the best method as a tip ("Best Tip"). It is a tip, yes, even a good one to some. But the best tip? Is that the way to promote fine woodworking? I don't think so. But as someone has commented elsewhere, the quality of FWW has been slipping over the years -- more in recent ones.

Simon
Perhaps they meant the best tip of the month?

[Rob Luter]

Frank Klausz shows a related technique to make waterproof joints in a YouTube clip.


https://m.youtube.com/watch?v=PitVHP7omvY

[Brian Holcombe]

Peened the joints, it dripped for two hours then stopped. These are super simple, just rabbets.

https://brianholcombewoodworkerblog.files.wordpress.com/2017/08/img_7400.jpg

[Chris Parks]

In a few strokes with a shoulder plane, I can do what this "best tip" will do. I am constantly learning but this isn't something I will try.

Simon

The idea is NOT to remove material and allow the wood to slowly come back to its original dimension. Planishing hammers can also be had with a square head like the one sitting in my tool box. This would allow working closer to the shoulder of the tenon. Peening is best described as putting divots into the material being worked and is commonly used to stretch metal prior to planishing which smooths the stretched metal. This link shows images of peening

https://www.google.com.au/search?q=peening&client=opera&hs=2rg&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj_7p2Rhs7VAhUKWbwKHaG3BWgQsAQIUg&biw=1227&bih=591

[William Fretwell]

While the technique may seem crude at first it is actually sophisticated! It uses the properties of wood to add a new technique that metal and plastic won't accommodate. Well you can supercool metal to get a tight fit, or heat it as in wagon wheel rims but plastic won't work!
Once the joint is together and tight who is to know? Good to have in your arsenal for those odd occasions.

[Simon MacGowen]

The idea is NOT to remove material and allow the wood to slowly come back to its original dimension. Planishing hammers can also be had with a square head like the one sitting in my tool box. This would allow working closer to the shoulder of the tenon.

If I took the title of the tip as a guide, the idea -- whether about compressing or not -- is about ease of assembly and a locked joint.

Both are easily achieved in the usual mortise and tenon techniques by cutting a snug fit joint. In a snug fit joint (whether achieved through fine tuning using a shoulder plane, or a chisel, etc.), you only need hand force to insert the tenon into the mortise, achieving the first stated goal of easier assembly. If one needs to use a hammer to pound a tenoned piece into a mortised piece, that is not a snug fit in my book.

When glue is applied to the mortise and (only) the front part of the tenon (I don't put glue all over the tenon for better squeeze out control), the tenon will swell when it is completely inserted, resulting in a locked joint.

Tell me what I am missing when I don't think the tip offers anything extra (other than a different approach). The majority of mortise and tenon failures are not because of assembly difficulty or wood not swelling, but because of a poor fit, the gappy kind.

The tip says "make the fit a bit snug" and then proceed with the peening and vise clamping, etc. If a snug fit is there, the joint will be strong. Why take the extra steps of using a hammer and a vise?

While I won't go as far as to say that it is a solution created to solve a non-existent problem, I would say this: it is a tip, fine. But as the Best Tip (yes of the month; don't think there is a Best Tip of the Year or anything like that), no. To me, it is a clumsy, crude way of doing any mortise & tenon joint with no added benefits than what is already out there, other than novelty. If you are good at doing mortise and tenon joints by hand as I but want to try it, go ahead, there is no harm -- even if you found out it is really not something you would do, unless your goal is to slow down your work.

The technique may have its use elsewhere as some suggested. No one is arguing otherwise, as far as I have read the posts. The tip may be unusual, but this subscriber of the magazine is not convinced that it deserves the recognition it has been awarded. You are free to agree with the editor's choice, whether or not you are one of its readers. I foot my subscription and as a competent woodworker, I know I am more than good enough to challenge anything published that I disagree with, like this tip award.

Simon

[Brian Holcombe]

History provides insight, and items such as windsor chairs suggest that glue alone is not enough to secure the joint in many cases. Windsor chairs are made with a green wood seat and kiln dried spindles to ensure that the spindles grow and the seat shrinks. They have very few failures. By comparison many glued chairs are coming apart within 50 years.

Ultimate strength is not usually the most important factor in joint failures (though sometimes it is!) more often a joint is simply worked apart over time and method such as this work to prevent such failure. This is the reason that often things like draw-boring are preferred to glue in many cases, even though glue likely makes a stronger joint in terms of ultimate strength.

[Simon MacGowen]

Ultimate strength is not usually the most important factor in joint failures (though sometimes it is!) more often a joint is simply worked apart over time and method such as this work to prevent such failure. This is the reason that often things like draw-boring are preferred to glue in many cases, even though glue likely makes a stronger joint in terms of ultimate strength.

I agree with that and I am also aware of the skilled work you do, Brian. But the peening and clamping technique under discussion is subject to the same constraints with regard to glue failure. If a joint fails because of glue, peening the joint will have no effect whatsoever.

I want people -- skilled ones and beginners as well -- to understand that not everything published in a magazine, even the FWW, is untouchable. FWW has a great pool of woodworkers and contributors, but i have spotted errors (not referring to typos) that have missed the editors' eyes. We have seen all the time corrections published by the editors, proving we are all human. If I sat on the tips review panel, this tip would be challenged to the end and would still be published but not as the Best Tip under my watch.

Simon

[Frederick Skelly]

I want people -- skilled ones and beginners as well -- to understand that not everything published in a magazine, even the FWW, is untouchable.

Hi Simon.
Yup, I definitely get your point there. I've seen flawed tips too. I posted this mainly because I'd never seen this done and didn't know what to make of it. I think this has all been a good well-rounded discussion and I've learned alot from all of it.

IMO, the tip was probably the most significant that FWW had this month, so that's the reason it got (current) top honors. As others have said, one would use it when/where it makes sennse - another tool in the toolbox of techniques, so to speak. More than one way to do most jobs.....

Fred

[Simon MacGowen]

Hi Simon.
Yup, I definitely get your point there. I've seen flawed tips too. I posted this mainly because I'd never seen this done and didn't know what to make of it. I think this has all been a good well-rounded discussion and I've learned alot from all of it.

IMO, the tip was probably the most significant that FWW had this month, so that's the reason it got (current) top honors. As others have said, one would use it when/where it makes sennse - another tool in the toolbox of techniques, so to speak. More than one way to do most jobs.....

Fred

Thanks, Fred, for making this interesting discussion possible to start with! I would not have written to FWW about my viewpoint, because I have had no intention to make their iife (difficult enough) more difficult. As someone who has its magazine from issue #1, I hold them to a higher standard than the rest.

As I said, I would not have had the same strong opinion about this tip if it were chosen as the best one in, say, Wood or Woodsmith. With people like Christian Becksvoort, Garrett Hack and the iike they can easily consult, the editors, if in doubt, could have checked with any one of them to see if that was the kind of fine woodworking practice they would like to promote. A new woodworker would think that one of the best ways to cut a mortise and tenon joint is to use a hammer and a vise, because it is one of the best tips in FWW.

Simon

[Brian Holcombe]

I dumped the water out of that tray this morning and attempted to pull it apart by hand. Now mind you, it's a 1/4" deep rabbet joint in softwood that has been peened and then moisture applied. I could not get the joint apart by hand.....a rabbet joint!

I have some complaints about how the tip was conveyed, especially the mention of the incorrect side of the hammer as far as I'm aware. But the technique does work when employed properly and so it should be conveyed to interested people.

[Erik Christensen]

Funny but I read the same tip and came away with an entirely different concept. To me the tip was not about how to achieve a better fit or lock the joint but as a way to insure that a joint is not glue starved due to a tight fit displacing it when assembled. I understood that the process is: fit the tenon snugly, then shrink it temporarily by peeing and/or vise, add glue to mortise & tenon, assemble and the nice even coat of glue will swell tenon back to origional fit.


I got the tip as - here is how to get good glue coverage in a tight fitting tenon.

[James Waldron]

About that "best tip" thing: it's a lot like saying that Josh McCown is the New York Jest best quarterback. That's damning with non-existent praise.

Let it go, man.

[Hasin Haroon]

I'm very intrigued by this technique, and for me it was a useful tip (as I would never think to do this myself). Theoretically it makes sense, and looks like others use it with a lot of success...I'm looking forward to trying it out myself.

[James Pallas]

If I remember my history studies correctly. This technique is used in boat building. Wet environment. It was also used for window sashes, thru mortises no glue sometimes wedged. Wet environment again. I wouldn't guess it would be necessary for furniture that is in a controlled environment. Could be used for outdoor furniture and similar things if it weren't for modern "waterproof" glues.
Jim

PS If you have spent time around wood plank boats you probably know that a lot of them leak like a sieve until the spring soaking is completed.

[James Waldron]

[snip]
Jim

PS If you have spent time around wood plank boats you probably know that a lot of them leak like a sieve until the spring soaking is completed.

That's why (in part) there ain't a lot of 'em being built these days!

Cold molded and strip planked wooden hulls are still being built in fair numbers, usually with a fiberglass outer layer. Plank built (clinker or lapstrake) is mostly relegated to historic and nostalgic building by focused and dedicated enthusiasts. The vast majority of modern boats are formed of "frozen snot" as specified by L. Francis Herreshoff some years ago.

(That's fiber reinforced polymers to you and me, aka polyester or polyepoxy fiberglass.)

[James Waldron]

Mr. Herreshoff was a woodworker, among other passtimes. His designs are some of the best works in wood ever. My personal favorite is sv Araminta:

365909
Click This

His father, Nathaniel Herreshoff, was pretty good too. Try google images under "Herreshoff boats" when you want to have your breath taken away.

[Stanley Covington]

Peening wood like this is called "kigoroshi" in Japanese （木殺し）which directly translated means "killing wood."

It works very well with softer woods (vs softwoods) like pine, spruce, larch, and cedar, the cells of which rebound quickly and to nearly their original dimensions over time and the application of moisture. It does not work well so well with harder woods like oak, maple, or beech because the cells do not rebound as completely. Perhaps it is because the cell walls are stronger but less elastic. Idduno. You can easily confirm this phenomenon at home.

I don't know where the technique was developed, or how came to be used in Japan.

I think a lot of people see Japanese craftsmen as working slowly and precisely. Precision is important, but speed is important too, so "slow" is not tolerated. If a carpenter cutting and fitting a timber frame in the field can make a housed dovetail tenon, for example, fit tighter faster using kigoroshi, and appearance will not be sacrificed, he is justified in doing so. But make no mistake, in the case of carpentry work, kigoroshi is not superior to carefully fitting the tenon using plane and chisel. In carpentry, at least in my experience on jobsites in Japan, kigoroshi is more often than not seen as a quick fix for a joint that was cut too tight in the shop. It's easy to get carried away with kigoroshi.

I can't recall seeing a carpenter do kigoroshi on a tenon. That would be seen as a sign of careless work since he has complete control over the dimensions of both tenon and mortise. But doing kigoroshi on the sides and bottoms of beams fitted into housed joints, where the sides and/or bottom surface of the beam must fit into a tight mortise, is more common, I suspect. The fit of such joints is dependent on the beam's dimensions, which are not so easy to control, and frequently require fine adjustments in the field.

In fine joinery, such as doors, windows, furniture and casework, kigoroshi is seen as crude. The craftsman has precise control of all dimensions. Kigoroshi has the potential to mess up the dimensions of the finished work when it swells, and can even cause joints to crack.

Where kigoroshi becomes extremely useful is in wood connections that are exposed to water. Cooperage. Wooden bathtubs. Boats. Exposed timber frames. All softwood construction BTW.

I have seen Hinoko bath tub makers cut the dados in the sides of the tub that fit into the rabbets in the tub's bottom, and other sides, intentionally oversized. The dados will not fit into the rabbets. He then uses a hammer to kigoroshi the dado, whereupon it fits tightly into the rabbet tightly. No glue is used, but when the tub is filled with water, the dado swells, locking it into the rabbet, and creating a watertight joint.

This URL is to a youtube video of a guy making a bathtub for a TV program. The bathtube was commissioned by a customer in Los Angeles, the story goes. Sorry it is in Japanese, but the video is informative. What is different from the craftsman I saw in person is that the bottom and sides are not joined by a rabbet/dado, and that he uses Hinoki bark caulking to prevent leaking at he bottom joints. https://www.youtube.com/watch?v=ZDesC_Bk4iA

Boats use the same technique. They also kigoroshi the lapped portion of hull planks. When the planks gets wet, the joint swells watertight, and stays that way even when the boat dries out.

Stan

[Frederick Skelly]

Thanks Stan. I always enjoy your posts. As usual, that one gave me a lot of insight.

The video was good too. I didn't even need to speak Japanese to follow it - it was very well done.

Best regards,
Fred

[Brian Holcombe]

Thanks Stan, that confirms a lot of my speculative thoughts on kigoroshi. I don't use it very much at all and my feeling has been as you noted; always softwoods and primarily in conjunction with wood that will be in contact with water.

I recall we had discussed it briefly with regard to chisel handles and hammer handles and both were considered a no-no because it damages hardwoods in a way which they do not recover from and so should not be used on hardwoods at all.

[James Waldron]

I've never used the technique on joints, but about that hardwood recovery thing: I have addressed accidental "dents" in hardwoods with a damp cloth and heat and found that the recover rather nicely if things are not too extreme. I've even had pretty good results with hard maple. That would seem to suggest that hardwood compression and rebound may be possible, but I'm sure there are more delicate constraints to be observed. At a guess, I would suggest that heat serves as an accelerator in the process and may not be an essential part of the recovery.

I'm not going to test the idea, but it might make a nice project for some interested individual. For me, I prefer firmly fitted joints and limit my usage to fixing dents and dings (and strive to make those rare).

[Simon MacGowen]

In fine joinery, such as doors, windows, furniture and casework, kigoroshi is seen as crude. The craftsman has precise control of all dimensions. Kigoroshi has the potential to mess up the dimensions of the finished work when it swells, and can even cause joints to crack.
Stan

If any of the Fine Woodworking editors is reading this, they should know next time when it comes to Japanese techniques, at least they can turn to you for advice. (But I think they had been just lazy as they could also have checked with Andrew Hunter about whether hammering and clamping a tenon is indeed a first-rate furniture technique (never has been, without doubt, in my mind)).

Unless their plan was to change its name to Crude Woodworking.

Simon

[Stanley Covington]

I recall we had discussed it briefly with regard to chisel handles and hammer handles and both were considered a no-no because it damages hardwoods in a way which they do not recover from and so should not be used on hardwoods at all.

True. There has been a lot of materials science research in Japan, and I read some papers on it when I was a student. Kigoroshi does not greatly decrease the strength of softwoods, within limits of course, but the cells of hardwoods are irrecoverably weakened. Don't recall the percentages, but it was significant. Sorry, but I don't have copies of the papers anymore, and yes, they were in Japanese.

Another very astute observation was made by Mr. Waldron. Kigoroshi is not usually combined with heat or steam, just water. In carpentry work, in my experience, they don't even use water. With time and weather changes, the pine or cedar will swell naturally. Not sure if oak would....

Perhaps I lack in skills, but the idea of cutting a door, furniture or casework joint and then trying to "lock" it using kigoroshi and moisture is mildly repulsive to me now. The very idea of pounding a shoji joint home with a hammer is shocking.

If I cut a M&T joint, and glue it, the tight fit will wipe all but a fine film of the glue off the tenon when inserted. The glue alone will lock it so tightly that the joint would be destroyed before it could be disassembled. I am sure your joints are the same way.

I don't mean to offend those that see Mr. Odate as a saint of Japanese woodworking, but I will share a story of an embarrassing incident for me. I read the article in FW by Mr. Odate about making shoji a long time ago when FW was still black and white and Mr.Odate was a spry artist. He instructed that the narrow sides (vs wider cheeks) of mortises should be sloped inwards towards the bottom (making the mortise narrower/tighter at its bottom) so that the rail's tenons are compressed when hammered home. He also advocated using rice paste as a glue because the joints could be disassembled later.

I made quite a few shoji for homes and restaurants in Las Vegas and Salt Lake city using these techniques, and they worked OK, but they had problems. I went back to Japan again soon after, and showed my new master, Mr. Honda, a renowned joiner, Mr. Odate's techniques. The old boy looked at me in deep disgust like I had cockroaches scrambling in an out of my facial orifices.

Mr. Odate's technique is a version of kigoroshi. It messes up the tolerances and precise positioning of the rails. Precision is critical in shoji and other such joinery work. Mr. Honda made it clear that kigoroshi is not a sound technique where precision is required with slender parts. I had experienced the difficulties Mr. Honda mentioned, and so could only agree as I turned red with embarrassment.

But, silly boy that I was, I did try to argue about the rice glue. It makes sense, right? This time, he gave me a sad face as his rheumy old eyes followed the cockroaches, and said: "Why would you ever want to take a rail/stile joint apart, Stan?" You need the glue to keep the joint tight over the shoji's 70 year lifespan. Rice glue is weak. Kigoroshi tenons will loosen over time and with stress. "Try hard not to be a fool, and maybe you'll average out as just an idiot," he concluded. Wise words. SHMBO insists they didn't take root in my case.

Kumiko joints are not glued with anything, and can be repaired when they break. But rail/stiles joints are forever.

Stan

[Stanley Covington]

Mr. Herreshoff was a woodworker, among other passtimes. His designs are some of the best works in wood ever. My personal favorite is sv Araminta:

365909
Click This

His father, Nathaniel Herreshoff, was pretty good too. Try google images under "Herreshoff boats" when you want to have your breath taken away.

Beautiful! Do they swim as good as they look?

[Stanley Covington]

If any of the Fine Woodworking editors is reading this, they should know next time when it comes to Japanese techniques, at least they can turn to you for advice. (But I think they had been just lazy as they could also have checked with Andrew Hunter about whether hammering and clamping a tenon is indeed a first-rate furniture technique (never has been, without doubt, in my mind)).

Unless their plan was to change its name to Crude Woodworking.

Simon

I haven't read FW in many years. You can probably guess why. Of course, I didn't read the article/tip in question, so I won't comment. But I doubt FW has much interest in the opinions of someone as un-journalistic as moi. I have very limited skills as a shill. And I'm absolutely terrible at selling powertools, handy dandy dovetail router jigs, or tablesaws that refuse to cut hotdogs.

[Brian Holcombe]

True. There has been a lot of materials science research in Japan, and I read some papers on it when I was a student. Kigoroshi does not greatly decrease the strength of softwoods, within limits of course, but the cells of hardwoods are irrecoverably weakened. Don't recall the percentages, but it was significant. Sorry, but I don't have copies of the papers anymore, and yes, they were in Japanese.

Another very astute observation was made by Mr. Waldron. Kigoroshi is not usually combined with heat or steam, just water. In carpentry work, in my experience, they don't even use water. With time and weather changes, the pine or cedar will swell naturally. Not sure if oak would....

Perhaps I lack in skills, but the idea of cutting a door, furniture or casework joint and then trying to "lock" it using kigoroshi and moisture is mildly repulsive to me now. The very idea of pounding a shoji joint home with a hammer is shocking.

If I cut a M&T joint, and glue it, the tight fit will wipe all but a fine film of the glue off the tenon when inserted. The glue alone will lock it so tightly that the joint would be destroyed before it could be disassembled. I am sure your joints are the same way.

I don't mean to offend those that see Mr. Odate as a saint of Japanese woodworking, but I will share a story of an embarrassing incident for me. I read the article in FW by Mr. Odate about making shoji a long time ago when FW was still black and white and Mr.Odate was a spry artist. He instructed that the narrow sides (vs wider cheeks) of mortises should be sloped inwards towards the bottom (making the mortise narrower/tighter at its bottom) so that the rail's tenons are compressed when hammered home. He also advocated using rice paste as a glue because the joints could be disassembled later.

I made quite a few shoji for homes and restaurants in Las Vegas and Salt Lake city using these techniques, and they worked OK, but they had problems. I went back to Japan again soon after, and showed my new master, Mr. Honda, a renowned joiner, Mr. Odate's techniques. The old boy looked at me in deep disgust like I had cockroaches scrambling in an out of my facial orifices.

Mr. Odate's technique is a version of kigoroshi. It messes up the tolerances and precise positioning of the rails. Precision is critical in shoji and other such joinery work. Mr. Honda made it clear that kigoroshi is not a sound technique where precision is required with slender parts. I had experienced the difficulties Mr. Honda mentioned, and so could only agree as I turned red with embarrassment.

But, silly boy that I was, I did try to argue about the rice glue. It makes sense, right? This time, he gave me a sad face as his rheumy old eyes followed the cockroaches, and said: "Why would you ever want to take a rail/stile joint apart, Stan?" You need the glue to keep the joint tight over the shoji's 70 year lifespan. Rice glue is weak. Kigoroshi tenons will loosen over time and with stress. "Try hard not to be a fool, and maybe you'll average out as just an idiot," he concluded. Wise words. SHMBO insists they didn't take root in my case.

Kumiko joints are not glued with anything, and can be repaired when they break. But rail/stiles joints are forever.

Stan

Interesting, I'm glad to read that about the kumiko. I've stopped gluing my kumiko joints and insist lately that should fit tightly together off the saw, and so far so good. I noticed them assembling tightly enough that I did not need to do anything to secure them and so friction along with the paper seem enough to keep them in place and I feel assured that I can replace a piece if it is somehow damaged without going through too much hell. For stuff I make for my own shop I don't glue the frame in place, they're just friction fit into the frame. For clients, a couple dabs of hide glue around the interior.

I haven't used kigoroshi in furniture joinery, but wanted to keep the door open earlier in this discussion to avoid it being condemned in every speciality having mentioned its use by boat and tub builders. I wasn't quite sure how this is viewed on the whole in Japan so I'm glad that you commented on the use of it with more specific uses. I had assumed similarly, but hesitated to comment specifically as I wasn't sure if it was commonplace to use it in sashimono work (but I assumed either not much or quite limited), and I has suspected it would be looked at quite poorly in shoji work as I never see it being used.

More often that not the sloped sides probably caused the joint to pop open and show a gap at the shoulder?

[Stanley Covington]

More often that not the sloped sides probably caused the joint to pop open and show a gap at the shoulder?

There are three significant problems with the compression joint.

First, especially in shoji with slender stiles (kamachi), the forces wedging the rail's tenons in place can combine to cause the stiles to warp. If you glue the kumiko's tenons in place, they will help to straighten this out.... until they don't. The thing about the stiles is they must align with the columns at each end of the opening, and with the stiles of the adjoining shoji. Easy to do with a single hamegoroshi shoji, not too hard with just a set of two, but four or six shoji in one span can make this challenging. Any unintended warpage of these stiles will quickly turn an intense task into a nightmare.

Second, an unintended consequence of crushing the tenon is that its dimensions are changed, and the amount of dimensional change to each side of the tenon is not necessarily equal, creating the risk of the rail being shifted up or down, some unforseen amount, instead of being precisely centered. This in turn creates problems for fitting the precisely cut kumiko vertically. More trouble, more shaving, more wasted time.

Third, and especially in the case of slender top and bottom rails, the amount of meat left between the tenon and the end of the stiles is small. Pounding the tenons into place tends to split the mortises after the horns are cut off. If the mortises expand and split, the fit in the tracks goes bad. If the piece of the mortise is pushed downward into the track, the shoji are tilted slightly.

The test of a set of shoji's or itado's quality is not just the appearance and quality of the individual shoji or itado, but how they fit and work with each other, how they move in the tracks, and the SOUND they make when moving. Don't forget the sound. Compression joints complicate all this with little benefit. Cut it right, cut it tight, and glue it.

[Stanley Covington]

I've stopped gluing my kumiko joints and insist lately that should fit tightly together off the saw, and so far so good.

A wise decision, Brian.

A sound, detailed plan, a good eye (knowing how good work should look, feel, smell, sound, and perform), proper preparation, and execution with precision, speed, and deftness are the sign of a professional versus a hobbyist in all human endeavors. One critical skill to reaching this level in woodworking is saw work that produces the right dimensions the first time every time without shaving, trimming, or shimming.

But the eye is the most important tool the human possesses. Training it takes time, effort, and money. If you get a chance, come over.

Stan

[James Pallas]

A discussion such as this one is exactly why I hang around here. I try to use the appropriate joint for the work. Sometimes one try's to use a method that works for one purpose but not others. Knowing what to use where is important. You may need to hammer tenons on a boat joint that won't be glued because of water but unwise to do it on your cabinet build. Hundreds of years, even thousands of years have taught the lessons. Isn't it great that the knowledge still exists and we don't have to do all of the trial and error stuff over again. Just a thought.
Jim

[Frederick Skelly]

A discussion such as this one is exactly why I hang around here. I try to use the appropriate joint for the work. Sometimes one try's to use a method that works for one purpose but not others. Knowing what to use where is important. You may need to hammer tenons on a boat joint that won't be glued because of water but unwise to do it on your cabinet build. Hundreds of years, even thousands of years have taught the lessons. Isn't it great that the knowledge still exists and we don't have to do all of the trial and error stuff over again. Just a thought.
Jim

Me too Jim. I agree completely.
Fred

[Brian Holcombe]

Thanks Stan, that makes a lot of sense. I could certainly see where you'd want to maintain the strictest level of precision when it comes to groups of four and six. In those tall red cedar shoji I made earlier in the year were certainly the 'ah-ha' moment for me, having everything multiplied by the sheer dimension of them being both tall and narrow the finest of changes had a large effect. It began to cement the idea in my mind that a good shoji is nothing short of a swiss watch movement in that every small change has a big effect and everything counts.

If ever presented with the opportunity I will certainly take you up on that. I would love to do so!

[James Waldron]

Beautiful! Do they swim as good as they look?

A good many of them do, even today. Some of Cap'n Nat's boats are still in service after more than a hundred years, although he didn't always use construction designed for long life. He was building light for racing most of the time. Some of 'em were so light they broke after a couple of seasons. But they were mostly winners on the race course and knock-your-eye-out beautiful things.

L. Francis designed a lot of cruising boats and they were built better and lasted better. But they were fast too. One of the all-time great ocean racers is Ticonderoga, original name Tioga II, a 71 foot (on deck) ketch:

366369 Click This

She's a record setting racer, a fabulous work in wood and famous throughout the world's ports for her beauty and grace. She's the favorite of a lot of sailors. I last saw her in St. Barts, looking smashing. She gets around a lot, even now.

Traditional boat building is woodworking plus. Lots of other crafts (foundry work in bronze, plumbing, electrics, gasoline and diesel engine maintenance, etc. The craft is being preserved through museums, craft schools and traditionalists.

I'm not one of the traditionalists, but I surely can admire their craft and sometimes learn from it.

[James Waldron]

Just stumbled into this:

https://www.youtube.com/watch?v=f7HaAZ1ugcA#t=349.161

I guess some use goes on in Japan.

Edit: I wasn't looking for it, I promise. It popped up at the end of a vid I was watching and the title jumped out at me.

Sorry.

[Stanley Covington]

Just stumbled into this:

https://www.youtube.com/watch?v=f7HaAZ1ugcA#t=349.161

I guess some use goes on in Japan.

Edit: I wasn't looking for it, I promise. It popped up at the end of a vid I was watching and the title jumped out at me.

Sorry.

I think this is the URL you intended to paste: https://www.youtube.com/watch?v=f7HaAZ1ugcA

[Stanley Covington]

Where kigoroshi becomes extremely useful is in wood connections that are exposed to water. Cooperage. Wooden bathtubs. Exposed timber frames. All softwood construction BTW. Boats use the same technique. They also kigoroshi the lapped portion of hull planks. When the planks gets wet, the joint swells watertight, and stays that way even when the boat dries out. Stan Below is a link to a Youtube video of a shipwright using a version of kigoroshi for planking a wooden ship. He uses a metal roller, and diring a second step, a hook to prep the joints between planks before caulking. This entire series of videos is very interesting for those into traditional techniques in woodworking. https://www.youtube.com/watch?v=Ox8r9SoDF3U&list=PLzlN3A2DLgNx6VDFT9mDNA4pN-r1dFwgL&t=172

[Frederick Skelly]

Thanks Stan. I'll go watch it!
Fred