Anyone tried this: Peening your tenons

[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:

Attachment 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:

Tioga.jpg 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