I just don't get it

[James Pallas]

I read all the things about "Don't scrape the bottom of mortises with your chisels", "You need 35* bevels on chisels" and so on. Yet we take a plane iron with a 25* bevel and shove it with both legs into wood, knots, edge grain, and some very hard wood at a 45* angle and expect it to keep performing. I do get the thing about more brittle steels chipping if you pry with them, that goes for screwdrivers with hard tips too. I also understand there may be issues if you use a 2 lb. hammer like Thor in a fight. But just using your chisel with normal hits with a mallet in a straight manner or scrapping a little is going to ruin the edge.
Tell me what I'm missing here.
Jim

[Stanley Covington]

I read all the things about "Don't scrape the bottom of mortises with your chisels", "You need 35* bevels on chisels" and so on. Yet we take a plane iron with a 25* bevel and shove it with both legs into wood, knots, edge grain, and some very hard wood at a 45* angle and expect it to keep performing. I do get the thing about more brittle steels chipping if you pry with them, that goes for screwdrivers with hard tips too. I also understand there may be issues if you use a 2 lb. hammer like Thor in a fight. But just using your chisel with normal hits with a mallet in a straight manner or scrapping a little is going to ruin the edge.
Tell me what I'm missing here.
Jim

If you aren't experiencing chipped/rolled/dulled edges with the methods you are using now, then the solutions to these problems others have suggested are irrelevant. That explains why you "don't get it."

For others, they are real problems, right now. They do "get it."

These problems have been around as long as humans have been using steel chisel and plane blades. They are not new solutions. Chances are you may need to apply these solutions to your work in the future. Maybe not. It all pays the same.

[Prashun Patel]

I always thought it was the depth of cut and levering the tip that was detrimental to the edge of the mortise chisel. That applies a lot of force across instead of into the tip.

When planing, the tip is never levered.

This being said, I tend to scrape the bottoms as you do, and it works ok for me. But I hop mortises by hand infrequently.

[ernest dubois]

I read all the things about "Don't scrape the bottom of mortises with your chisels", "You need 35* bevels on chisels" and so on. Yet we take a plane iron with a 25* bevel and shove it with both legs into wood, knots, edge grain, and some very hard wood at a 45* angle and expect it to keep performing. I do get the thing about more brittle steels chipping if you pry with them, that goes for screwdrivers with hard tips too. I also understand there may be issues if you use a 2 lb. hammer like Thor in a fight. But just using your chisel with normal hits with a mallet in a straight manner or scrapping a little is going to ruin the edge.
Tell me what I'm missing here.
Jim
James, I think you have to dial in on the question or problem as you see it like a laser or it will be asking for trouble. For example, there is no problem in, "just using your chisel with normal hits" and "scraping a little" will never "ruin the edge". In your question as posed, there are no problems despite the conclusions and assumptions other readers will be prone to draw and then carry on about page after page. For example, I would ask one thing, did you ever have a problem using your chisel and mallet normally?

[Stewie Simpson]

I always thought it was the depth of cut and levering the tip that was detrimental to the edge of the mortise chisel. That applies a lot of force across instead of into the tip.

When planing, the tip is never levered.

This being said, I tend to scrape the bottoms as you do, and it works ok for me. But I hop mortises by hand infrequently.

Prashun; have a listen to what Frank Klaus says at 1min in the following video about prying the waste free with a mortise chisel. https://www.youtube.com/watch?v=PQ6vBrqHH3A

[Matt Evans]

When planing, the tip is never levered.


That is the main difference.

If you don't have the issues with your mortise chisels chipping, cracking, or dulling quickly, then you may just have some chisels that have more forgiving steel than some others. It also sounds like you may simply have found your own natural "chip Limit" and "Mallet force" which means you likely aren't overtaxing your chisels in the first place. (I do a lot of larger scale mortises, and tend to go a bit overboard on occasion, and that is where I run into the most issues)

The Narex set that I have is great, but it definitely a little more brittle than the older chisels I've used. I've taken to using a cranked neck chisel to clean the bottoms of smaller deep mortises to help conserve the Narexs tips.

One other note: The deeper the mortise, the more straight line force you put on the tip of a chisel when levering. So, the bottom of a mortise on a deep mortise is going to see the greatest chance of a tip breaking off or chipping. To illustrate this you can draw an arc with a set of dividers with the depth of the mortise being the circles radius. Please excuse the poor upside-down illusration .

[Warren Mickley]

Without watching you work it is tough to know whether you are being rough with your chisel. If you need a 35 degree bevel or some weird steel for a mortise chisel, then these are clues that your mortising technique is none to clean. When I read about whacking or bashing or a chisel that must stand up to abuse, I am thinking that the writer is hard on his tool.

If a mortise is just a little shallow for the length of tenon, I usually make a series of shallow cuts along the bottom so that each cut pushes the waste toward the previous cut. That way everything down there is already loose if you want to lever it out. I generally mortise to within 5/16 of the far side of the stile, which leaves a little cushion for the chisel to avoid breaking out the back. Scraping the bottom strikes me not so much as abusive, but as a slow way to extend the depth.

[Jeff Heath]

Not all chisel steels are created equally, and not all people use/abuse/whack them the same way. These angles that always talked about should be used as a guideline as a place to start. Once you've done some work, you'll be able to hone in on what works best for you, based on the species of wood you use, and how hard you're hitting your chisel with a mallet. Big bites, and a lot of prying, are going to be harder on an edge. I have learned, over the years, how hard I can push my tools without damaging them. My sharpening station is 10 feet from my bench, so if I sense a chisel or plane iron is dulling, I either pick up another chisel in the same size (I have many) or go sharpen it again. There's a trade-off between a sharp edge and a steeper bevel angle. You'll figure out what works best for your situation, and your style of work.

[Jim Koepke]

I read all the things about "Don't scrape the bottom of mortises with your chisels", "You need 35* bevels on chisels" and so on. Yet we take a plane iron with a 25* bevel and shove it with both legs into wood, knots, edge grain, and some very hard wood at a 45* angle and expect it to keep performing. I do get the thing about more brittle steels chipping if you pry with them, that goes for screwdrivers with hard tips too. I also understand there may be issues if you use a 2 lb. hammer like Thor in a fight. But just using your chisel with normal hits with a mallet in a straight manner or scrapping a little is going to ruin the edge.
Tell me what I'm missing here.
Jim

One thing to remember when it comes to a plane blade is its support system. A thin blade, compared to a mortise chisel or just about any other chisel for that matter, has a frog under it and cap iron and lever cap on top of it. In a plane the blade is usually limited to taking a shaving less than a 1/16". A mortise chisel may be moving a chip four or five times that in a single whack.

The force of my mallet blow for mortising is the hardest whacking any of my in shop wood working tools receive. The really hard whacks are saved for splitting wedges and usually outside with extra room to swing a sledge.

At the end of the video Stewie linked Mr. Klaus shows a rather large lock mortise or swan neck mortise chisel that is made to get down into a mortise and clear the bottom of a mortise. Another method is to make the mortise a little deeper than the length of the tenon. That provides a little space for any extra glue. The bottom of a mortise doesn't have to be pretty.

jtk

[James Pallas]

I really don't think I'm having problems with chisels. I do wonder about all of the different opinions. I don't own any expensive chisels. I did at one time buy some chisels from a popular tool maker and ended up giving them away. They were nice chisels felt good in use. They were harder to sharpen and supposedly needed a different bevel angle. I have what I call inside and outside chisels. The inside ones I use at the bench and the outside ones I use for rougher work such as repair work or working on wood that is very dirty like my deck or something. I have owned chisels that were just no good, would not hold an edge cutting bass wood or something such as that. Would not even be good paint can openers. I have for years sharpened at 25* or a little more for bench chisels and 20* or so for paring. I've never felt that I had to sharpen more than necessary. More often in harder wood for sure and I expect that. If I have a chisel that folds I believe something is wrong, if it chips maybe I hit something or could be the steel. I can usually hear with the first hit if the wood is harder than I expect it to be and can adjust my technique for that work. I was just wondering about all of the comments that I read about it. Mortise chisels I try to keep at 30* +. Good comments here about the subject.
Jim

[Jim Koepke]

I really don't think I'm having problems with chisels. I do wonder about all of the different opinions.

Hopefully all of the different opinions circle back to people expressing what is working for them in their work.

What actually works for you in your work environment is reality. Everyone knows, or should know, one reality is worth more than an infinite number of opinions.

jtk

[Patrick Chase]

Prashun; have a listen to what Frank Klaus says at 1min in the following video about prying the waste free with a mortise chisel. https://www.youtube.com/watch?v=PQ6vBrqHH3A

Like many such rules, the prohibition from prying seems to be frequently broken by those with enough skill (not me). Obviously Klaus has a sense of just how hard he can lever his chisel without chipping or folding the tip, so he takes advantage of that to accelerate the waste removal process a bit.

[Jim Koepke]

Like many such rules, the prohibition from prying seems to be frequently broken by those with enough skill (not me). Obviously Klaus has a sense of just how hard he can lever his chisel without chipping or folding the tip, so he takes advantage of that to accelerate the waste removal process a bit.

What sharpness can't fix must be left to experience.

jtk

[ernest dubois]

I do wonder about all of the different opinions.


And the tool flippers, advertisers and the huge racket around them all know it, want you to be just curious enough to spend your money to see if what they all say just might be so. They will be wooing you with the newest gimmick, mystifying you with the numbers and the jargon and most of all belittle you for not having the latest.

[James Pallas]

And the tool flippers, advertisers and the huge racket around them all know it, want you to be just curious enough to spend your money to see if what they all say just might be so. They will be wooing you with the newest gimmick, mystifying you with the numbers and the jargon and most of all belittle you for not having the latest.
Nice one Ernest. There is that saying, "Believe none of what you hear and only half of what you see." I stopped going to that dance about 60 years ago when I got my first paying job. I'm not buying it unless I put it in my own hands. Same thing for trying things, I only believe it after I have done it.
Jim

[Patrick Chase]

And the tool flippers, advertisers and the huge racket around them all know it, want you to be just curious enough to spend your money to see if what they all say just might be so. They will be wooing you with the newest gimmick, mystifying you with the numbers and the jargon and most of all belittle you for not having the latest.

Or it could be that different tools/systems work for different tasks and individuals.

I very much doubt that the craftspeople who invented the sokozari (and its Western equivalent) were engaged in a long-running conspiracy to enable evil capitalist 21st-Century ironmongers to take your money. They did so because they saw a problem in their own work, and they came up with a tool to fix it. If you or Frank Klausz can forego it by doing limited scraping with your chisels then more power to you, but that doesn't mean that the dedicated tool is the product of a "racket".

I think that where we're on more solid ground is when we question the need for more modern "innovations". When I see a product that was technologically feasible in 1800 or 1900 but that wasn't made back then, my "gimmick detector" rockets to 11. It's a bit tougher to judge when the product wasn't previously feasible, as in the case of some newer steels for example.

[steven c newman]

Hmmm the old " Dazzle them with Brilliance, or Baffle them with....."

Remember what they said about opinions.....

[ernest dubois]

Or it could be that different tools/systems work for different tasks and individuals.

I very much doubt that the craftspeople who invented the sokozari (and its Western equivalent) were engaged in a long-running conspiracy to enable evil capitalist 21st-Century ironmongers to take your money. They did so because they saw a problem in their own work, and they came up with a tool to fix it. If you or Frank Klausz can forego it by doing limited scraping with your chisels then more power to you, but that doesn't mean that the dedicated tool is the product of a "racket".

I think that where we're on more solid ground is when we question the need for more modern "innovations". When I see a product that was technologically feasible in 1800 or 1900 but that wasn't made back then, my "gimmick detector" rockets to 11. It's a bit tougher to judge when the product wasn't previously feasible, as in the case of some newer steels for example.
I don't know this Klaus figure and also never felt the need to pretty up the bottoms of my mortice as some Japanese must, and which I can respect given that context. The idea of a specialized tool is problematic because of its subjectivity and provides this fertile ground exploitable by evil Capitalists.

Consider this, and please, provide the examples of contradictory evidence, I'm always open to the possibilities, but the last new idea in woodworking was the biscuit joiner introduced by the Swiss sometime late last century. For the rest we have two categories, gimmick or variations/refinements of the very basis concepts long ago established. And then think of this, Veritas tools.

[Stanley Covington]

I don't know this Klaus figure and also never felt the need to pretty up the bottoms of my mortice as some Japanese must, and which I can respect given that context. The idea of a specialized tool is problematic because of its subjectivity and provides this fertile ground exploitable by evil Capitalists.

Consider this, and please, provide the examples of contradictory evidence, I'm always open to the possibilities, but the last new idea in woodworking was the biscuit joiner introduced by the Swiss sometime late last century. For the rest we have two categories, gimmick or variations/refinements of the very basis concepts long ago established. And then think of this, Veritas tools.

Two points:

First, the Japanese sokozarai is a not a gimmick but a tool designed to accomplish a specific task. As you may know, the longer the tenon in a mortise & tenon joint, the more glue area, the more friction, and the more resistance to racking (to a point) is provided. Ergo, the through-tenon. But in most countries, including Japan, until recently, exposed end-grain was considered a sign of unrefined craftsmanship, and through-tenons were seen as country-bumpkin work. If we look at a door frame therefore, the optimal and elegant mortise & tenon joint has a mortise that is just shy of penetrating all the way through the stile, with only a very thin layer of wood remaining in the bottom. Indeed, light should come through. To achieve this, the craftsman needs a tool to actually shave the bottom of the mortise to a uniform depth/thickness. That tool is called the sokozarai. Even if you scrape away with your mortise or bench chisel, you will not be able to accomplish this detail without a sokozarai, or a very very very very tiny router plane. But there is no equivalent in the Western tradition that I am aware of, although I know timber framers that improvise a similar tool for cleaning mortises.


Another point:

Let us examine the router plane. The origin of this tool is the "Old Hag's Tooth." This is an ancient and venerable tool. But there is no equivalent in Japan, where they see it as a strange tool of little practical use.

The point is that traditions exist for a reason, and a wise man will try to figure out those reasons before criticizing. We would not want to create fertile ground to be exploited by bloody-handed socialists.

[Rob Luter]

I read all the things about "Don't scrape the bottom of mortises with your chisels", "You need 35* bevels on chisels" and so on. Yet we take a plane iron with a 25* bevel and shove it with both legs into wood, knots, edge grain, and some very hard wood at a 45* angle and expect it to keep performing. I do get the thing about more brittle steels chipping if you pry with them, that goes for screwdrivers with hard tips too. I also understand there may be issues if you use a 2 lb. hammer like Thor in a fight. But just using your chisel with normal hits with a mallet in a straight manner or scrapping a little is going to ruin the edge.
Tell me what I'm missing here.
Jim

I'm late to chime in, but my plane irons, bench chisels, and mortise chisels all have different edge geometry to foster durability in their intended applications. I can pry and scrape with my mortise chisels because the cutting angle is steeper than on my bench chisels. This said, I can't pare with them. I use my bench chisels with a shallower cut angle. I also don't whack them with Thor's hammer. I'd also never consider blowing through knots with a smoothing plane. I'd use another tool with a more durable edge. I have no "one size fits all" expectations with respect to edge prep.

[James Pallas]

Everyone is making good points here. Warren's about tool abuse, Ernest's about tools not needed, and Stanley's about why a tool is needed. I never knew that in Japanese work that it is expected that the bottom of a mortise be clean or the reason why. I think I understand Warren's points about it's may not be the tool but the technique. I don't think I have a need at this point in my work to carefully clean the bottom of a mortise but I now know the how and the why. I've never been one to buy gimmick tools but they are all over the place. I look at those tools like diet fads, the answer to that problem is well known. Tool abuse is a rampant thing see it done a lot. If you find that a tool is not working there must be a reason, too small, too big, not sharp, not being used as intended and the rest of a long list. Thanks for all the comments. I feel more confident now that in fact I do "get it".
Jim

[Robert Engel]

Tool abuse is a rampant thing see it done a lot.
Jim

Torturing a tool ought to lead us to a question "is there another way?" Yes, there's a better way to address a knot.

Specific to the mortise question you brought up, I would ask "Tellm me why does the bottom of a mortise need to be flat?".

In a more broader sense, in general, how essential is an effort when no one will see it and it doesn't affect integrity of joint?

I sometimes find myself in the vortex of self satisfaction over "doing it right" when in the final analysis, my efforts are inconsequential to the piece.

(BTW if you just have to have the mortise bottom flat, a sharpened paint can opener works fairly well.)

[Stanley Covington]

Torturing a tool ought to lead us to a question "is there another way?" Yes, there's a better way to address a knot.

Specific to the mortise question you brought up, I would ask "Tellm me why does the bottom of a mortise need to be flat?".

In a more broader sense, in general, how essential is an effort when no one will see it and it doesn't affect integrity of joint?

I sometimes find myself in the vortex of self satisfaction over "doing it right" when in the final analysis, my efforts are inconsequential to the piece.

(BTW if you just have to have the mortise bottom flat, a sharpened paint can opener works fairly well.)

I suspect your question was mocking, but since you asked it, I will answer it for the benefit of all following this thread. It is not an easy point to misunderstand

Unlike furniture or interior finishes, doors, windows, and shoji are moved by hand, often violently, and are subject to high loading from alternating directions. They are abused. Unless they are replaced, burned, eaten by bugs, or rot, eventually, they all fail, and the cause of that failure is clearly visible to the end user. If the reason for that failure is a sloppy mortise and tenon joint, do you doubt the consumer will complain to the craftsman that made it? Might that customer's dissatisfaction turn into word-of-mouth that will harm the craftsman's reputation? In Japan, you can bet your sweet bippy it will.

In the Japanese tradition, doors, windows and shoji are handled daily by small women with particular sensibilities. The doors, windows and shoji must therefore be lightweight and elegant in appearance, not heavy and clunky like castle joinery (depending on the architectural style, of course). The sensibilities are different. Even the sound a shoji makes is noticed by and important to these picky women. Believe me, the last thing you want is for a Japanese woman to start criticizing your work.

I am constantly doing factory inspections of joinery, furniture, millwork, stone, floor finishes, light fixtures, curtainwall, sash, doors, etc. for the projects I am in charge of. Often, Japanese women with the Client, architect, interior designer, or my staff attend with me (or on my behalf). It is truly scary how nit-picky these women are. I almost always have to make them backdown on their complaints during these inspections or nothing would ever get delivered to the jobsite on time. Japanese craftsmen, manufacturers and suppliers are used to this, indeed, expect it.

Over the life of a wooden sliding door, window, or shoji, the demands on their mortise and tenon joints are high. The physics pertaining to doors, windows, shoji, and other joinery include bending moments, shear forces, friction, withdrawal forces, force couples, crushing forces. These are not imaginary.

If a craftsman is unable or unwilling to make a clean flat bottom, then the tenon that will reside in that mortise must be made correspondingly shorter, and joint integrity may indeed be compromised to some degree. Simple physics.

You may not see the importance of this detail, but a lot of craftsmen over many centuries have made a living performing this hidden detail many times a day. They are/were not hobbyists. Their motivation is/was not just self-satisfaction, but quality.

In your job, your fellow workers may not mock you for neglecting to make your mortise bottoms clean, thin and uniform. Your customers may not demand this kind of quality, or examine failed joints with jaundiced eye, and complain with a serrated steel tongue. Your boss may not fire you if you neglect to work to these standards. But for some craftsmen, it is/was an essential part of their job. For essential jobs, specialist tools are often developed to increase efficiency and accuracy.

If you don't plan to work to these standards, and for these kind of Clients, then a sokozarai is not an essential tool for you.

[James Pallas]

Stanley, please keep going. Is there any concern for wood shrinkage with the tenon being full length of the mortise? I have on rare occasions seen tenons punch thru or separate at the shoulder is why I ask. Is the same standard with thin bottoms used in timber framing?
Jim

[Warren Mickley]

I have to agree with Stanley on the importance of tenon length. Short tenons are liable to break out the cheeks of the mortise or, if pinned, to split out between the pin and the end of the tenon.

In my area many customers expect a through tenon in frame construction. This is partly because through tenons are used in the finest 18th century Philadelphia furniture. However, it is also because seeing the end of the tenon is their assurance that the craftsman did not use cheapo tenons that only go halfway through the stile, or worse.

[steven c newman]

They do make a chisel for cleaning out the bottom of mortises here.....called a lock mortise chisel. Designed for cleaning up the bottoms of mortises.

Then again, there are a few "Homemade" versions out there...
381388
No..this isn't a screwdriver....
381389
It started life as an adjuster for drum brakes on a car. Was reground into a chisel shape, a tang was ground for the handle....The curve has a bevel down profile..
381390
1/4" wide, can be struck with a mallet, or just use you hand. Works nicely in the mortises I make.
YMMV...

[Edwin Santos]

I don't know this Klaus figure and also never felt the need to pretty up the bottoms of my mortice as some Japanese must, and which I can respect given that context. The idea of a specialized tool is problematic because of its subjectivity and provides this fertile ground exploitable by evil Capitalists.




Torturing a tool ought to lead us to a question "is there another way?" Yes, there's a better way to address a knot.

Specific to the mortise question you brought up, I would ask "Tellm me why does the bottom of a mortise need to be flat?".

In a more broader sense, in general, how essential is an effort when no one will see it and it doesn't affect integrity of joint?

I sometimes find myself in the vortex of self satisfaction over "doing it right" when in the final analysis, my efforts are inconsequential to the piece.

(BTW if you just have to have the mortise bottom flat, a sharpened paint can opener works fairly well.)




In your job, your fellow workers may not mock you for neglecting to make your mortise bottoms clean, thin and uniform. Your customers may not demand this kind of quality, or examine failed joints with jaundiced eye, and complain with a serrated steel tongue. Your boss may not fire you if you neglect to work to these standards. But for some craftsmen, it is/was an essential part of their job. For essential jobs, specialist tools are often developed to increase efficiency and accuracy.

If you don't plan to work to these standards, and for these kind of Clients, then a sokozarai is not an essential tool for you.

Hi,
Interesting discussion. Sometimes context can make understandable what otherwise might seem absurd. I've had some experience with Mr. Klausz, having taken two separate week long classes with him. In one he demonstrated the hand cut mortise behind glass right in front of us. He also brought a "hag's tooth" that he said was older than his own grandmother would be, and he demonstrated using it to clean out a hand cut dado (much shallower than the mortise obviously).

Here's a little bit of his story - he was apprenticed as a young teenager in the old world European tradition which involved conditions that some today might call abusive. For example, ignoring the destruction and then rebuilding of self-esteem at the hands of the shop master, and the penance of being the low man in the shop hierarchy, he worked 16 hour days that ended with sleeping for the night in a cot in the unheated workshop, only to wake up the next morning and do it again. The emphasis in the shop was aimed at some balancing point between European craftsmanship standards and practical trade production, not a whole lot of philosophy. Your craftsmanship was part of your trade and your trade was how you put food on the table. Most importantly every hand tool technique he demonstrated was one he had done thousands of times (maybe tens of thousands of times?), so it didn't take long for all of us in the class, regardless of experience, to defer our own opinions to Frank's way. You quickly learned not to contradict what Frank was saying based on what you read in some blog, that's for sure.

Switching continents, I've had the good fortune to spend some time in Japan and develop a fascination and respect for all things Japanese. While I would defer to Mr. Covington any day of the week on the subject, I picked up on the introduction of a cultural philosophy in craftsmanship that is not present in quite the same way in Frank's old world European tradition. Implicit in this cultural philosophy are concepts such as personal self-improvement, advancement along a never ending path striving for perfection, beauty exists not only where you can see it but also where you cannot see it (and where only the craftsman knows it). It's difficult to articulate some of these ideas, especially considering their roots come out of Asian thinking which is not as strictly linear and literal like our thinking in the West. However - and this is important - none of these ideas exist at the expense of the practical and functional, including the efficiency and economy of the tradesman. The Japanese craftsman is trying to maintain his commitment to certain principles, but put food on the table too.

I share this because it might speak to why a craftsman in Japan would concern himself with the bottom of a mortise, even to the point of adopting a tool for a purpose that seems questionable to another. It's for a practical, functional joint strength reason but also a personal philosophical reason. Coincidentally or not, I'm told the Japanese tradition of craft apprenticeship may not be that different than what Frank described, although I've never heard a Japanese person yell quite like he did (and that was to a group of grown adults who were paying money to take his class).

Please excuse the rambling, and not to suggest that anyone's opinion in this thread has been right or wrong per se. I thought some additional context and perspective might explain what might otherwise look like conflicting ideas (and maybe a few similarities also).

I'll admit a personal bias insofar as I can appreciate the old world European work that Frank showcased all day long, but there is a manner in which the intangible Japanese philosophies I've tried to describe can actually present themselves in the finished work in a way that is quite beautiful. It's as though the craftsman's person is revealed to you in some way even though he/she is nowhere to be found.

Edwin,

[ernest dubois]

I hope nobody it assuming that tenons not scraped or cut with this bottom chisel of the Japanese are not accurate. It's not a problem chopping a flat bottom mortice in the conventional way. It's only logical that a tenon should have maximal length to make a stronger joint. This is part of the basic knowledge that goes into joint selection . Where the joint like that is required the standard I know is leaving 5 mm thickness remaining, inclusive of 2 mm free space, where a through tenon is excluded. I can accept that Japanese may have even a smaller tolerance in this instance since Japanese joinery is much more involved and requires far greater skill.

The bottom cutting chisel is a gimmick but not in and of itself. For the shoji maker of Japan working in the context Stan has laid out certainly not but in a different context where the rational is not only not understood, maybe even incomprehensible and certainly not readily accessible - how many owners of these chisels in the West understand the Japanese attitude towards exposed end grain I wonder - it becomes an object exotic and mysterious and so, maybe something that can compensate for missing skill.

[Warren Mickley]

I laughed when I read Klausz's method for hand mortising in a 1979 Fine Woodworking article. Over the next decade he wrote articles and made videos about making mortises by machine. I assumed that machine mortising was his standard method.

About five years ago I saw a new video of Frank using a mortise chisel. In this video his was using a technique similar to what I have done for forty years, not what was in his 1979 article. I guess here in America even an old world cabinetmaker can learn how to do hand work.

[Mike Allen1010]

Edwin thanks for your very insightful comments regarding what customers value from the Japanese and traditional European perspective and how that might differ with contemporary western consumers. IMHO, very helpful in understanding how those consumer preferences influenced woodworking techniques in different cultures.

[Edwin Santos]

I laughed when I read Klausz's method for hand mortising in a 1979 Fine Woodworking article.

Warren,
I don't think I'll be able to locate the article you mention, so what may I ask what was it about his technique for hand mortising that made you laugh?

[Patrick Chase]

Warren,
I don't think I'll be able to locate the article you mention, so what may I ask what was it about his technique for hand mortising that made you laugh?

http://www.finewoodworking.com/1979/10/01/more-on-mortising

The diagrams show the chisel being used to make a series of vertical cuts to the same depth, working from one end of the mortise to the other. They indicate that the cuts should be made using the back as a reference, and that the chisel should then be rocked towards its bevel to lever out the resulting vertical slabs of waste, effectively using the edge as the fulcrum (!).

If you look at more recent video of Frank in action (https://www.youtube.com/watch?v=PQ6vBrqHH3A) he now rides the bevel diagonally instead of riding the back vertically, and rocks the chisel towards the bevel such that the top of the bevel serves as the fulcrum to lever the waste, both of which are preferable to what the '79 article showed in my experience. I believe Warren does something along those lines as well.

One thing to consider is that Klausz didn't actually create the problematic drawings from the '79 article. They're credited to Rick Mastelli who IIRC was an editor or staff writer at the time. The accompanying text that Klausz did write doesn't describe the specific chopping technique that he uses except to say that it's roughly similar to Ian Kirby's. Editors add filler like that to articles after submission all the time, and in this case it looks like they had a column to fill (maybe they didn't sell all of their allocated ad space that month?) and created diagrams until they had enough.

So the bottom line is that while the article unquestionably dishes out some awful advice, I'd think twice before dismissing Klausz out of hand on that basis.

[ernest dubois]

Edwin thanks for your very insightful comments regarding what customers value from the Japanese and traditional European perspective and how that might differ with contemporary western consumers. IMHO, very helpful in understanding how those consumer preferences influenced woodworking techniques in different cultures.
Not to go picking at nits but in all fairness to Edwin, it was Stanley who claimed or implied that the force driving the Japanese woodworker to excellent work was strictly crass commercialism. Edwin on the other hand clearly credits honor, beauty, integrity, constant self-improvement and all these high-minded ideals as the motivation behind the work. There is quite a difference between the two, although the one not necessarily exclusionary of the other and maybe Stanley and Edwin were just busy emphasizing two different points. Still we ought to keep the ideas of who said what straight and not go around mixing things up.

[Warren Mickley]

http://www.finewoodworking.com/1979/10/01/more-on-mortising

The diagrams show the chisel being used to make a series of vertical cuts to the same depth, working from one end of the mortise to the other. They indicate that the cuts should be made using the back as a reference, and that the chisel should then be rocked towards its bevel to lever out the resulting vertical slabs of waste, effectively using the edge as the fulcrum (!).

If you look at more recent video of Frank in action (https://www.youtube.com/watch?v=PQ6vBrqHH3A) he now rides the bevel diagonally instead of riding the back vertically, and rocks the chisel towards the bevel such that the top of the bevel serves as the fulcrum to lever the waste, both of which are preferable to what the '79 article showed in my experience. I believe Warren does something along those lines as well.

One thing to consider is that Klausz didn't actually create the problematic drawings from the '79 article. They're credited to Rick Mastelli who IIRC was an editor or staff writer at the time. The accompanying text that Klausz did write doesn't describe the specific chopping technique that he uses except to say that it's roughly similar to Ian Kirby's. Editors add filler like that to articles after submission all the time, and in this case it looks like they had a column to fill (maybe they didn't sell all of their allocated ad space that month?) and created diagrams until they had enough.

So the bottom line is that while the article unquestionably dishes out some awful advice, I'd think twice before dismissing Klausz out of hand on that basis.

Klausz had no trouble nitpicking a previous article on mortising by Kirby; in fact it was his critical letter about this that led to his association with the magazine. If he knew the drawing was wrong, I think he would have made a fuss.

Klausz also made a video on mortising shortly after the article appeared, which I watched at a tool store. The video covered machine mortising and hand mortising, so I did see him show his method in this video. I believe there were several different methods of machine work. For hand work, he was working very differently decades later.

[James Pallas]

The posts by Stanley and Warren now bring another question for me. If you chop verticle and then push an already cut chip out of the way doesn't that put less stress on the tip of the chisel then chopping down and then using the top of the bevel as a fulcrum to pry out the chip. It occurs to me that prying especially with Japanese chisels is not to be done.
Jim

[Stanley Covington]

The posts by Stanley and Warren now bring another question for me. If you chop verticle and then push an already cut chip out of the way doesn't that put less stress on the tip of the chisel then chopping down and then using the top of the bevel as a fulcrum to pry out the chip. It occurs to me that prying especially with Japanese chisels is not to be done.
Jim

You bring up a good point. The location of the pivot point aside, using the chisel to flick cut chips out of the mortise-in-progress will not damage the cutting edge appreciably. With experience and attention, one can learn how to cut mortises to provide space for severed chips to displace into, where they can then be flicked out of the hole without unduly stressing the chisel's cutting edge. Usually, but not always in my experience, a V cut centered on the mortise works most efficiently for this.

The problem arises when the chisel's cutting edge is thoughtlessly wedged tightly into the bottom of the mortise-in-progress, and then is used from this position to pry out unsevered wood. This puts a lot of stress on the cutting edge in its weakest direction.

If you stop cutting at the right point, before the chisel wedges tightly, and then flick out the severed chips in one movement, your chisel and hammer will remain in constant movement, and you will develop a rhythm that will allow you to cut very quickly and precisely. Of course, your cutting edges will stay sharper longer. This is the way of cutting mortises I was taught by very senior professionals in Japan. I did not invent it.

As I mentioned in another thread, if you doubt what I write, please test it in a controlled situation. I did. Very few make that effort, but just spout half-baked opinions. It is human nature to ask for advice, but to reject anything that does not agree with what they feel comfortable doing already.

I should add one thing. I am generally critical of convex (rounded) bevels on chisel blades because it does not typically help precision, and is more time consuming to sharpen. However, as I have stated before in this forum, when cutting large/deep mortises, a rounded bevel is very useful for flicking out the chips. It makes it easier to rotate the chisel in a scooping movement as the cut is in progress and seems to pop the chips out automatically.

In small mortises, however, the rounded bevel requires extra clearance to be effective, space that is often not available. In this case, the standard flat bevel is superior IMO.

[Warren Mickley]

A few notes. You want to ride the bevel whenever possible. This puts the cutting angle at 60 degrees to the fibers. Cutting straight down (riding the back) cuts the fibers at 90 degrees. Also when cutting straight down, the bevel pushes the waste down into the hole, not the best strategy.

When levering out waste you want to be working with loose chips, not prying stuff still solid. Penetrating deeply with a hollow ground or a secondary bevel causes the tip to become deeply embedded in solid tissue, where it is vulnerable.

[Stanley Covington]

A few notes. You want to ride the bevel whenever possible. This puts the cutting angle at 60 degrees to the fibers. Cutting straight down (riding the back) cuts the fibers at 90 degrees. Also when cutting straight down, the bevel pushes the waste down into the hole, not the best strategy.

When levering out waste you want to be working with loose chips, not prying stuff still solid. Penetrating deeply with a hollow ground or a secondary bevel causes the tip to become deeply embedded in solid tissue, where it is vulnerable.

Excellent additional information.

[Pat Barry]

A few notes. You want to ride the bevel whenever possible. This puts the cutting angle at 60 degrees to the fibers. Cutting straight down (riding the back) cuts the fibers at 90 degrees. Also when cutting straight down, the bevel pushes the waste down into the hole, not the best strategy.

When levering out waste you want to be working with loose chips, not prying stuff still solid. Penetrating deeply with a hollow ground or a secondary bevel causes the tip to become deeply embedded in solid tissue, where it is vulnerable.
Thanks Warren. This is a very crisp and vivid explanation of proper method.

[James Pallas]

Exactly answers I wanted to see. There is so much written about having big heavy mortise chisels and driving them with so called lump hammers that it could be confusing. I always felt, right or wrong, that the large handles on mortise chisels and wide face mallets are there so you can watch the work progress instead of watching your aim for the hammer hitting the chisel. There are some cases where this is not true, such as a railroad spike hammer when it is more important not to hit the rail so the head is smaller than a sledge for busting rock.:)
Jim

[James Pallas]

I should say here that I do cut straight down. The only time that I ever broke the tip on a mortise chisel was fulcruming off the bevel. I do listen to the sound that the tools make and stop when the tone changes. I also tend to lighten up on the downward pressure when levering the chip. That being said maybe I should mend my ways and try the other way again. I still don't know if I'm ready to take a steel hammer to a chisel tho.:)
Jim

[Edwin Santos]

A few notes. You want to ride the bevel whenever possible. This puts the cutting angle at 60 degrees to the fibers. Cutting straight down (riding the back) cuts the fibers at 90 degrees. Also when cutting straight down, the bevel pushes the waste down into the hole, not the best strategy.

When levering out waste you want to be working with loose chips, not prying stuff still solid. Penetrating deeply with a hollow ground or a secondary bevel causes the tip to become deeply embedded in solid tissue, where it is vulnerable.

This clarifies the issue for me very well. Thank you!

[Patrick Chase]

A few notes. You want to ride the bevel whenever possible. This puts the cutting angle at 60 degrees to the fibers. Cutting straight down (riding the back) cuts the fibers at 90 degrees. Also when cutting straight down, the bevel pushes the waste down into the hole, not the best strategy.

Nice, succinct description.

The approach in the FWW article is even worse than you say, because it shows the bevel being levered down even further at the end of the cut to "remove" the waste.

[Patrick Chase]

Klausz had no trouble nitpicking a previous article on mortising by Kirby; in fact it was his critical letter about this that led to his association with the magazine.

On a tangent, I've always had a soft spot for Ian Kirby's writing, though I don't follow all of his techniques. His dovetail book was one of the first hand-tool WWing books that I ever read.

Kirby's article (the one Frank Klausz responded to) shows both approaches to cutting the mortise: http://www.finewoodworking.com/1979/04/01/the-mortise-and-tenon-joint. He also notes that the back-registered approach is best suited to cutting in layers instead of going to full depth all at once.