Are japanese chipbreakers set like western chipbreakers

[Paul Bent]

I have a 60 mm 4 piece plane which I am trying to set up and I can't find info on how close to set the chipbreaker. I use the "just a sliver" method on my western planes bd capiron when smoothing and wonder if that is the approach to use for japanese planes which seem to have a capiron on top?

[Brian Holcombe]

Very similar yes, they're set extremely close when taking finish shavings. The important part is that the setting show through in the chip. The chip should come up and out of the plane, straight.

I have a few posts on my blog WRT setting up Japanese planes.

https://brianholcombewoodworker.com/2016/08/11/hikouki-kanna-dai-prep/

https://brianholcombewoodworker.com/2016/08/04/hikouki-kanna-blade-prep/

[Paul Bent]

Brian, those were great threads. They answered a few additional questions which were coming up. My blade was significantly wider than the chipbreaker and I was wondering what I was missing with regards to it. Thanks!

[Brian Holcombe]

My pleasure!

[Paul Bent]

One more quick question. I currently have about 1/32" on my leading edge flat of the blade that the chipbreaker rests against. The corners and sides have approx 1/8 to /3/16th How do I get more metal at that front area. Do I use a flattening process similar to chisels to increase that area or something else?

I'm thinking I need the ura-dashi according to your blade thread but I'm unsure how to do it.

[Brian Holcombe]

Ura-dashi, but one need research this quite intensely before proceeding. Do you have an anvil or similar and appropriate hammer? Do you have any experience in working metal?

[Paul Bent]

I have a metal working vise and a little tack hammer. Am I just trying to lightly "push the metal" from the soft up into the hard? Hope that makes sense. Not to many videos out there.

[Brian Holcombe]

Check out Desmond King's blog and you may also want to purchase his book as he details the process.

A metal working vise won't be of much use in this case.

[Paul Bent]

Ok thank you very much.

[Patrick Chase]

I have a 60 mm 4 piece plane which I am trying to set up and I can't find info on how close to set the chipbreaker. I use the "just a sliver" method on my western planes bd capiron when smoothing and wonder if that is the approach to use for japanese planes which seem to have a capiron on top?

Adding one thing to what Brian said: As I understand it Japanese craftsmen were close-setting the cap irons of their double-iron planes all along. They didn't "lose the recipe" and then have to rediscover it with the aid of a Japanese video, as most Westerners did (with some notable exceptions like Warren).

[Paul Bent]

Here is a video that seems to give a pretty good overview. No, not in english but the comments are fantastic. https://www.youtube.com/watch?v=omy749ByoVQ :)

[Brian Holcombe]

That video looks pretty fantastic for the depictions of how it is done. You may well also want to join Piedmont Japanese Carpentry group on Facebook, one of the participants Jim Blauvelt, I think he can tap out plane blades in his sleep (and probably does).

Hopefully Stan Covington will comment here as well.

This video is a little more clear in the part where they actually do the job (less dark).


https://www.youtube.com/watch?v=UjbRcnESURI

If its any consolation, having a very thin edge is an easier fix than having uneven sides. I had to completely regrind the hollow on one (by hand!), but worth the effort as it is very easy to maintain now.

[Luke Dupont]

I had to completely regrind the hollow on one (by hand!), but worth the effort as it is very easy to maintain now.

I'm curious; how do you go about doing this?

[Brian Holcombe]

I used india slip stones to work the areas that needed specific attention, then finished the back with sandpaper (the hollow, not the edges) until I could get a good looking ura.

[Stanley Covington]

Most people (including myself) mistakenly chip a blade the first or second time they do uradashi, creating themselves a lot of work, and shortening the lifespan of the blade. But with caution you can avoid this.

The anvil can be most any piece of steel. A sledge hammer in a vise works fine, just be sure to use a rounded, smooth corner. Another option is a piece of min 1" black pipe with steel cap screwed onto the end. Make this long enough for one end to rest on the floor while clamped upright in the vise with the cap at a comfortable elevation. If you don't have a round, smooth corner, make one.

I suggest you place some duct tape on the anvil to help keep the blade from slipping. Of course, this wastes some energy, but that is better than a chipped or cracked blade.

The hammer should be pointy. Lightweight is best. The first video shows a big claw hammer. Not recommended since the face is so wide and it is more difficult to sense exactly where it is striking. A tack hammer or even a Warrington hammer works fine. I use a Yamakichi style. A light hammer is best since it gives you better control. The guys in the videos are striking too fast for a beginner, so don't try to imitate the speed.

Don't try to bend the blade. This is a big, rookie mistake. The correct process is to dent/deform the jigane (soft layer of steel) a tiny bit with each hammer strike. These dents/deformations will accumulate expanding the length of the jigane lamination and eventually bending the hardened and brittle steel layer in an evenly supported, safe manner. So you can see that there is no point in trying to bend the steel layer with mighty blows.

The spot on the ura (hollow part of the blade) precisely behind the hammer's impact MUST be supported directly on the corner of the anvil. This allows the hammer's impact forces to induce maximum deformation to the jigane. In the other words, the forces of the hammer strike need to flow straight from the point of impact on the jigane, through the blade, and into the anvil without causing the blade to dance and jiggle and twist. You will feel the alignment is right when you find it. Every strike of the hammer should be aligned with the same sweet spot on the anvil. You need to shift the blade a tiny bit left or right between each hammer strike in order to walk the dents across the blade's width. In the case of right-handed guy, the blade is typically held in the left hand, and the hammer in the right. Carefully tap with the hammer until you find the sweet spot on the anvil and memorize it with your right hand. Work the right and left hand in harmony as the blade is moved across the anvil, so the hammer always strikes in perfect alignment with the sweet spot on the anvil, while the left hand moves the blade across this point on the anvil in tiny increments.

Be patient!

Use a straightedge to check progress.

The majority of the blows should be at the center of the blade's width, becoming fewer the farther from the centerline. There is no point at all in working the far right/left edges of the blade that are clamped in the plane's block. Bending these areas will only cause you grief.

When flattening the ura, use a marking pen or dykem to color the areas being ground so you don't cut too far or unevenly. Be patient when grinding down so you don't round the cutting edge over. This is easy to do when using a rough grit of carbide powder on a kanaban grinding plate. Diamond plates work better than a grinding plate and carbide grit. Keep everything wet since the grinding forces at the very thin metal at the extreme cutting edge can get hot enough to ruin the steel's temper, especially with the finer grits. This won't ruin the entire blade, but it can make the blade soft for the first couple of sharpenings.

Stan

[Paul Bent]

Thank you Stan. I have more faith in understanding where to place the hollow in regards to the hammer strike and supporting surface and why.

[Stanley Covington]

Thank you Stan. I have more faith in understanding where to place the hollow in regards to the hammer strike and supporting surface and why.

You are welcome Paul. Despite their simple appearance, Japanese hiraganna planes are extremely sophisticated tools, and because of that sophistication, they can be a pain in the butt, with uradashi being perhaps the most difficult maintenance operation. I hope my explanation helps you to get your plane up and running again.

Stan.

[Paul Bent]

Ok two more questions. How hard and how close to the edge should I get. I can't see a laminate line in the blade. And I don't seem to be moving any metal. How many strikes offhand would you guess to start seeing something. I've probably done 30 with no apparent change.

And another. Why do my shavings and board (pine) have a much higher sheen even with the same thickness of shaving (translucent) compared with western planes sharpened the same way and same grit. BU and BD planes. I've set my plane so that it has 2 contact points.

[Brian Holcombe]

Paul, can you post a picture of what you've got so far?

[Paul Bent]

Will do it in the am.

[Steve Voigt]

Why do my shavings and board (pine) have a much higher sheen even with the same thickness of shaving (translucent) compared with western planes sharpened the same way and same grit. BU and BD planes. I've set my plane so that it has 2 contact points.

Without physically being in your shop it's impossible to say for sure, but here are some factors that could contribute:

- Your Japanese planes may be bedded at a lower angle than your Western (BD) planes. On a straight-grained board where tearout is not an issue, a lower angle will produce a more reflective surface. For BU planes, same thing, except the relevant metric is the effective cutting angle.

- Your Western irons may be A2 or some other high-alloy steel, and it may be impossible to get them as sharp as the very fine-grained, high-carbon steel in your Japanese irons. Or, it may not be possible to get them as sharp with whatever sharpening media you're using.

- The metal soles (I'm just assuming your Western planes are metal, I could be wrong) could be affecting the surface, particularly if there is any roughness to them.

- The chipbreakers on your Western (BD) planes may be set closer to the cutting edge, and/or the leading angle may be blunter. On a softwood like pine, a very close-set chipbreaker can have a detrimental effect on surface quality.

Some of these factors are more likely than others; the first one (bed angle or effective cutting angle) is a biggie. But the main thing to do is experiment.

[Patrick Chase]

Without physically being in your shop it's impossible to say for sure, but here are some factors that could contribute:

- Your Japanese planes may be bedded at a lower angle than your Western (BD) planes. On a straight-grained board where tearout is not an issue, a lower angle will produce a more reflective surface. For BU planes, same thing, except the relevant metric is the effective cutting angle.

While this is a very credible explanation in general, my experience is that most people who are skilled enough to get translucent shavings and high sheen with *any* plane are cognizant of cutting angle.



- Your Western irons may be A2 or some other high-alloy steel, and it may be impossible to get them as sharp as the very fine-grained, high-carbon steel in your Japanese irons. Or, it may not be possible to get them as sharp with whatever sharpening media you're using.

Same remark as for edge angle - it would surprise me if somebody could get translucent shavings without being attuned to the sharpness (or lack thereof) of their irons.



- The metal soles (I'm just assuming your Western planes are metal, I could be wrong) could be affecting the surface, particularly if there is any roughness to them.

Note that in the 2-contact-point setup that Paul described the freshly planed wood isn't touched by the sole of the Japanese plane at all, so that's a *big* difference.



- The chipbreakers on your Western (BD) planes may be set closer to the cutting edge, and/or the leading angle may be blunter. On a softwood like pine, a very close-set chipbreaker can have a detrimental effect on surface quality.


Yep. Close-set cap irons don't degrade surface finish as much as high cutting angles, but they do degrade it a bit.

[Warren Mickley]

The placement of the cap iron is an art. It is not as if one can just follow some formula and have a fine surface. You can't say "oh look, the shaving is straight" and then proclaim the surface perfect. It takes experience, knowledge of your material, discernment and judgement. It is a great help to do stock preparation by hand because one has some intimacy with the timber long before taking the final strokes. A cap iron that is set too close will make a mess of the surface.

I see lots of people get translucent shavings without being exceptionally sharp; the surface tells the story. It could be that Paul has neglected the back of his BU or BD plane iron, and that his Japanese iron with its recent work and its hollow is in better shape. I guess he likely he has some kind of high chrome iron.

[Steve Voigt]

While this is a very credible explanation in general, my experience is that most people who are skilled enough to get translucent shavings and high sheen with *any* plane are cognizant of cutting angle.
…
Same remark as for edge angle - it would surprise me if somebody could get translucent shavings without being attuned to the sharpness (or lack thereof) of their irons.


Neither I nor you really is in a position to say what the OP knows, or doesn't know. It seems safer not to assume.

[Stewie Simpson]

A cap iron that is set too close will make a mess of the surface.

Nicely stated Warren; some others are still playing catch with their idea of a super duper tight clearance on their cap iron.

Stewie;

[Patrick Chase]

Nicely stated Warren; some others are still playing catch with their idea of a super duper tight clearance on their cap iron.

Stewie;

And yet some others were insisting that high angles were the One True Solution For Tearout (tm) as recently as a few months back.

The funny thing is that everybody here said the same thing: Very closely set cap irons can compromise surface quality, and may explain what Mark saw. Nothing remotely Earth-shaking there.

[jamie shard]

Just some advice from someone who also chipped his blade (actually a chisel blade) the first time he tried it...

You can be quite far back from the edge with your hammer taps and still move metal. Nowhere close to the edge and actually a fair distance away from the lamination line. Trust that eventually enough taps will move the metal.

Check progress by rubbing on the sharpening stone. When you first see that your edge is moving downward you will be happy. You will need to keep going to get the ura, don't rush, just keep going with the small taps.

Listen to the sound of the anvil. If it "clicks" or "rattles" then the tap wasn't right over the anvil. Adjust until you get a nice dull tone, where the force of the hammer is going straight through the blade and right into the anvil.

I used the endgrain of some hardwood as an anvil the second time I tried (the first time I was successful). It was more forgiving but I was also going a lot slower and tapping a lot further from the edge.

Did I mention to trust that it will work and go slow and keep your taps well away from the edge? :)

[Paul Bent]

Having trouble uploading. Is there a file size limit? 2k+? 345754

On another note, I was able to finally get it to move the metal. I'm at 1/8th" now. Kind of a serpentine shape initially but I will get better. Now I have to figure out why I am jamming in one corner but search will be my friend.