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David Wong
01-26-2014, 1:26 AM
I have often read warnings of cracking a japanese plane blade if ura-dashi (tapping out the back) is done improperly, but I have never seen the failed results. Well, I cracked a blade tonight, and the results are horrible.

https://lh3.googleusercontent.com/-mqJ7ePTOCDI/UuShXbzuPeI/AAAAAAAAAeY/hfYU7Am9hS4/w800-h640-no/DSC01937.jpg

https://lh6.googleusercontent.com/-MK0OccbtqyA/UuShYVfdShI/AAAAAAAAAeA/wjpGmL3h30w/w1800-h640-no/DSC01938.jpg

I re-beveled the blade to a slightly steeper angle, and needed to tap out a new flat. I had just started with some light taps on the blade against my anvil, listening for a dull thud sound as I strike the blade to know the back is adequately supported. As I was making my way across the blade and establishing a rhythm, I saw the large semi-circular crack appear. Note that none of the hammer marks are near the edge.

This is not my first time attempting ura-dashi. I have successfully tapped out blades on 4 or 5 other times. What really surprised me is how the blade cracked when I was using fairly light taps. To fix this blade, I will have to grind off better than 1/4 inch of blade. This is no cheap blade. It is a good (i.e. expensive) Yamamoto swedish steel blade.

Bradley Gray
01-26-2014, 4:38 AM
What a drag. Do you think the weld failed?

Jim Matthews
01-26-2014, 8:48 AM
It does look like a clean fracture.

What sort of hammer was used?

David Weaver
01-26-2014, 8:52 AM
That stinks. What was the shape of the support under the edge. It wasn't similar to the break was it?

I remember reading a description that So had on his page about a really short iron that he was selling (or maybe he wasn't, sometimes it's hard to tell), where he said that he had to grind away a large part of the iron because it developed a crack when he was tapping it out.

george wilson
01-26-2014, 9:20 AM
The weld did not crack. The steel is very hard and brittle. Maybe TOO hard. It might well could use some tempering. What do you think,David? I do not use Japanese tools. They use very hard steels.

I see the 2nd. picture is the other side of the crack. Good. It will grind away with not too much loss. What I am concerned about is why the steel cracked. If it is just too hard,it will also be too brittle. The 2 go together. Usually Japanese blades get away with it because the hard steel is welded to a soft steel,which supports it. Could there have been a tiny chip or anything else on your anvil that pushed against the blade and caused that chip? Is your anvil flat,or worn with a wavey surface? That will cause a chip.

David Wong
01-26-2014, 2:34 PM
It is not uncommon for the leading edge of a newish japanese blade to be somewhat brittle. A few sharpenings may be needed to until the blade settles down.

My anvil is a japanese rail track shaped thing, and the surface I was using was smooth and gently curved. My hammer blows were from the edge of the head. My guess is that I was improperly supporting the back of the blade during one blow, and the blade flexed, causing the crack. Maybe supporting too far forward of the blow. I was choking up on the hammer so as to not strike too hard, but... After grinding, I'll try it again even less aggressively.

280857

They sell a mechanism specifically for ura-dashi, but the cost is ~$200. If it prevents me from cracking another blade, the cost would be worth it.

280855280856

Winton Applegate
01-26-2014, 3:04 PM
Hey !
This one looks right up my alley.
Or not.
You guys can shoot me out of the sky later but here are some thoughts. Keeping in mind I am no big essspurt on super hard laminated blades (though I have some).

Here are some general metal working things to keep in mind:

First the relatively un related . . .
the deep marks in the blade produced by the hammer concerns me. Use a "peen" like hammer to tap the blade when drawing out the metal. Meaning the area of the face of the hammer that is hitting the blade needs to be narrow, rounded and polished so you don't cut furrows in the blade. Hey at least you can plant potatoes now.

The anvil surface against the back side of the blade needs to be able to fit into the concave back of the blade. See the machine in the photo. Also his comment in the close up of the text. Ignore my underlining that was from when I read the book.

http://i801.photobucket.com/albums/yy298/noydb1/IMG_2491_zpscdcd24d9.jpg (http://s801.photobucket.com/user/noydb1/media/IMG_2491_zpscdcd24d9.jpg.html)

http://i801.photobucket.com/albums/yy298/noydb1/IMG_2493_zpsb8401c4d.jpg (http://s801.photobucket.com/user/noydb1/media/IMG_2493_zpsb8401c4d.jpg.html)

The book is a good one if you don't already have it.
http://www.amazon.com/Japanese-Woodworking-Tools-Tradition-Spirit/dp/0941936465/ref=sr_1_1?s=books&ie=UTF8&qid=1390765898&sr=1-1&keywords=toshio+odate


Next and I believe fairly, or perhaps critically, significant is the "stress risers" you have created from the grinding.
See (http://en.wikipedia.org/wiki/Stress_riser)
and
this (http://www.badgermetal.com/ml-vs-polish-stresses.htm)

I would recommend polishing the blade, at least on the bevel side where you were grinding to eliminate the scratches. The scratches ARE the stress risers.

Are you familiar with the way they cut glass ? They scratch it and then flex it and the scratch concentrates all the stress and channels it along the scratch and down into the glass bellow the scratch.
The curve of the crack and the curve of the scratch marks from the grinder are suggestive.

george wilson
01-26-2014, 3:17 PM
Yeah,I'll bet all the Japanese carpenters have that gadget!!

David Wong
01-26-2014, 3:45 PM
Thanks Winston. The stress risers are interesting. Normally, I grind by hand on 80 grit sandpaper, or a 220 grit waterstone. This was the first time I had used mechanical help, in the form of diamond lapidary wheels on a worksharp. The deep scratches were left behind by 100# and 500# wheels. I really liked the lapidary wheels because they did not really cause the blade to heat up. Something I am always afraid of on japanese blades. I do not use a peen hammer because I find it difficult to see exactly where I am striking. Also all other examples of tapping out that I have read or seen in videos, people have used the edge of their hammers to create those furrows. The area I am striking is soft iron, so an edged hammer helps to prevent the hammer from slipping.

Winton Applegate
01-26-2014, 7:56 PM
OK I hear you on the edged hammer. To be clear I wasn't saying use a "western" ball peen. I just wanted to create the image in the mind of the reader of a rounded and polished edge on the traditional Japanese hammer.


This was the first time I had used mechanical help, in the form of diamond lapidary wheels on a worksharp

Electrons are the Devil's work. Shun them or perish.

(just kidding)

Wilbur Pan
01-26-2014, 10:17 PM
My anvil is a japanese rail track shaped thing, and the surface I was using was smooth and gently curved. My hammer blows were from the edge of the head. My guess is that I was improperly supporting the back of the blade during one blow, and the blade flexed, causing the crack. Maybe supporting too far forward of the blow. I was choking up on the hammer so as to not strike too hard, but... After grinding, I'll try it again even less aggressively.

280857



Hi David,

I think you’re on the right track. Either your blade wasn’t supported well enough, or you hit the blade too hard or too close to the edge.

For me, I use a body shop dolly for an anvil. (This is a tool used to repair dents.)

http://farm3.staticflickr.com/2868/12164913983_ff126e07d7_c.jpg (http://flic.kr/p/jwYn7g)

I think the important thing is that the surface of this is nice and rounded, which helps me make sure that the plane blade is in good contact with the anvil. I don’t have a rail-type anvil, but I’ve seen them and I think it would be a little trickier to keep the blade in contact with the rounded area that is there. You might want to take a file and make that rounded area bigger, to give you more room for error.

The hammer on the left is the one that I use for tapping out. I put it next to a 375 g Japanese hammer for scale. My tapping out hammer is considerably lighter, at about 125 g. This reduces the chance of hitting the blade too hard. Even if you were choking up, a lighter hammer is easier to control

http://farm4.staticflickr.com/3717/12164676035_fbae478db3_c.jpg

Finally, here’s another view of the end of the hammer that I use for tapping out. Notice how much pointier it is.

http://farm6.staticflickr.com/5521/12165336886_4e827f5bba_c.jpg (http://flic.kr/p/jx1wPG)

I know it’s possible to tap out a plane blade with the edge of a regular Japanese hammer. It’s far easier to control the point of impact if the hammer is pointier. You may want to look into getting a lightweight tack hammer for tapping out. It’s going to be a lot cheaper than the tapping out jig, for sure. ;)

I have some more information on tapping out a plane blade here (http://giantcypress.net/post/5446904360/tap-tap-revenge), and a brief video here (http://giantcypress.net/post/5634759952/given-that-tapping-out-a-japanese-plane-blade-is-a).

David Wong
01-27-2014, 1:28 AM
That's a nice shaped hammer. I have been meaning to pick up a more suitably shaped hammer, like one for japanese boat building, but have not had occasion to do so.

I'm convinced I did not have the blade back adequately supported. The surprising thing to me was how large the fracture was relative to the strength of the hammer blow. I guess I am lucky that the blade looks like it can be recovered (fingers crossed).

Wilbur Pan
01-27-2014, 10:06 AM
Japanese boat builder hammers are readily available down to 6 oz (170 g). Hida Tool has tack hammers in 80g, 110g, 165g, and 225g sizes.

Fixing the blade won’t be as hard as you think. The hardest part is regrinding the blade so you’re past that crack, mainly because you don’t want to draw out the temper from overheating the blade. I use a Tormek (http://giantcypress.net/post/5446904360/tap-tap-revenge) when I need to do this, since the water cooling ensures that the blade won’t get too hot. I am sure that there are some people who can do this on a dry wheel grinder without screwing things up, but I’m not one of them.

jamie shard
01-27-2014, 11:04 AM
For what it's worth, using the end grain of a wood block for an "anvil" is a little more forgiving. Probably takes longer, but the "shock" seems less dangerous.

David Weaver
01-27-2014, 12:16 PM
The weld did not crack. The steel is very hard and brittle. Maybe TOO hard. It might well could use some tempering. What do you think,David? I do not use Japanese tools. They use very hard steels.


You might be talking to the other David, but I'll offer up a few observations that do come from decidedly limited use of tools (in terms of numbers and credibility):

* A lot of the mid-range stuff that's marketed to people isn't as hard as its spec says it is. 6 or 7 years ago, a friend bought an iyoroi mortise chisel that was specified 64 hardness, and it tested on an average of three strikes at 61. I didn't have a western chisel over 60, though I gave him a couple of things to test. My iyoroi chisels are probably about the same (61) - they are harder and hold their edge better than most of my vintage stuff, but they can be sharpened on oilstones. They do, however, still hold an edge better than anything else I have except for the harder japanese chisels. I believe my ouchi chisels are a tick or two harder, as are the koyamaichi (those two probably are what they say they are) - they barely barely sharpen on oilstones unless there are loose particles. In the balance of things with use, the iyorois are just as nice to use, but they are not the red oak handled iyorois that most people are used to seeing so I'm not telling people to go out and buy iyoroi for chisel nirvana. Mine are wrought iron backed and would be expensive to replace.

* Alex Gilmore (a dealer in sharpening stones and some vintage japanese tools) for a time was having vintage irons struck to determine their hardness. One of the things I see thrown around is age hardening, but his 50s vintage irons tested 60-62, and I didn't see any above 62. That's actually a really nice hardness to use on a carbon steel iron for japanese planes...62 or so. It doesn't really chip, it's easy to sharpen and quick because it doesn't chip. I believe that many of the modern irons are harder than the vintage irons, though I've heard more than one place that a lot of tokyo smiths made hard irons. It would take someone who knows what they're looking for to clarify that. Oilstones are a good test with carbon steel, because once something gets above about 62, they really struggle with it. I'm convinced the mosaku iron that I have is too hard, and chips a little compared to some softer irons I have. It's a bear to sharpen on any oilstones despite being white #1, and it's even a bit difficult on natural japanese waterstones.

* Some of the makers making irons now still aren't that hard. I'm convinced (and this is just tinfoil hatting) that most of the swedish stuff that's described as very easy sharpening is a tick or two softer than hitachi steel tools that come from tokyo and nigata. I've got an iron that is well regarded by the planing contest people over there (Ogata), and it takes a great edge, but sharpens extremely easily. It's softer than the mosaku by quite a bit. Part of that is because the backer is softer, but part is the steel. I have to admit that i like it better, too. Nothing unpredictable happens with it. Stan Covington mentioned that he had chipping problems with a mosaku plane that he got based on my comments, and I think he's cursed my plane, too!! The last time I used it, I had tiny chipping issues with it, and combined with its hardness, that can make for an undesirable session.

I also have two funjii (cheap brand) planes that are some kind of white or yellow steel, and they are probably about 60 or so hardness. They were marketed as 64. I use one as a jack with a ton of camber on it, it holds up very well at the hardness it is. It would be less nice to use for that coarse work if it was harder. It's my white collar plane (in that if you're not in shape enough to work pushing a plane continuously, you can put one that you pull into the mix and then go on working for a long period of time with nothing more than sharpening breaks).

My experience with yamamotos (having had 3) is that they are somewhere between in hardness. They are not as hard as the mosaku iron, but the ones I had (not swedish) were not exactly soft, either.

David Wong
01-28-2014, 9:43 PM
To conclude this thread...

While grinding the plane blade down, I uncovered a defect (or two) in the blade. As I ground the blade down near my scribe line, I noticed a black smudge on the ground part of the blade. I assumed it was just metal filings and water, as I just quenched the blade. I made another pass and found the black spots still there. On closer inspection, they are voids in the hard layer of steel. I am making the assumption that these voids right at the base of the crack line, caused the fracture.

https://lh5.googleusercontent.com/-bgOD5ZGeAEI/Uuhh-VLKowI/AAAAAAAAAfA/yeLm5NxM68Q/w1119-h554-no/DSC01960.jpg

I was able to recover the blade and tap out the ura. This blade was very difficult to tap, and I had to hammer dangerously low on the soft layer of the bevel to eek out barely 1mm of flat. I somewhat forced the process by excessive flattening of the back, so the ura is not very attractive. In future, I will switch to a more pointed hammer, as Wilbur suggested.

https://lh6.googleusercontent.com/-cOPkepd3XkM/UuhnvcaF7xI/AAAAAAAAAfU/nXbDZRdqV_w/w800-h640-no/DSC01967.jpg

jamie shard
01-29-2014, 11:04 AM
Very interesting, thanks for posting those images!

george wilson
01-29-2014, 11:16 AM
Just goes to show that metal can be defective even on expensive tools. Especially if they are forge welded. Heating high carbon steel up to sparkling white hot,very near the melting point to get it to weld is tricky business. The higher the carbon,the trickier as it burns up worse. It is hard to get high carbon to weld to low carbon(or wrought iron). Their welding temps are different. We have expert smiths in Williamsburg. They don't like to forge weld steel over 1080. Your blade is much higher carbon.

I have had to repair laminated blades on good American made antique chisels at the museum. One such was not even hardened,and the cutting edge curled back like a fish hook,seen from the side view. Another just plain came loose from the iron body of the chisel. I forget how many "high quality" old tools I had to repair or harden,etc.

I honestly cannot recommend tapping any tool with a hard lamination on a rusty,irregular surface. That is just asking for trouble. And I do not have to be a user of Japanese tools to know that.

Any way you can get a refund on that defective iron?

Winton Applegate
01-30-2014, 1:38 AM
For any one interested in the process of hand forging high quality steel blades (including making the steel from iron and carbon in an authentic duplication of an ancient furnace) (and modern laboratory authentication of the quality of the steel ) be sure to check out the Nova episode here (http://www.pbs.org/wgbh/nova/ancient/secrets-viking-sword.html).
Maybe overly dramatic . . . maybe not. I enjoyed the show.

Winton Applegate
01-30-2014, 2:04 AM
For what it's worth, using the end grain of a wood block for an "anvil" is a little more forgiving. Probably takes longer, but the "shock" seems less dangerous.

Toshio Odate in the book I posted photos of agrees with you. That was his practice and recommendation as well.

Wilbur Pan
01-30-2014, 9:28 AM
To conclude this thread...

While grinding the plane blade down, I uncovered a defect (or two) in the blade. As I ground the blade down near my scribe line, I noticed a black smudge on the ground part of the blade. I assumed it was just metal filings and water, as I just quenched the blade. I made another pass and found the black spots still there. On closer inspection, they are voids in the hard layer of steel. I am making the assumption that these voids right at the base of the crack line, caused the fracture.

Hi David,

Where did you get your plane?

David Wong
01-30-2014, 11:54 AM
Hi Wilber,

I got it from a shop in Japan.

http://www2.odn.ne.jp/mandaraya/kashin.html

Greg Portland
01-30-2014, 2:53 PM
For any one interested in the process of hand forging high quality steel blades (including making the steel from iron and carbon in an authentic duplication of an ancient furnace) (and modern laboratory authentication of the quality of the steel ) be sure to check out the Nova episode here (http://www.pbs.org/wgbh/nova/ancient/secrets-viking-sword.html).
Maybe overly dramatic . . . maybe not. I enjoyed the show.
It's now available on Netflix for those who subscribe...

jamie shard
01-30-2014, 5:12 PM
Toshio Odate in the book I posted photos of agrees with you. That was his practice and recommendation as well.

Thanks, I've been trying to convince him for a while. I'm glad he approves. :D

note: this statement in no way implies any actual conversation has occurred between the Mr. Shard and Mr. Odate. Further, no japanese plane blades were harmed in the writing of this post.

george wilson
01-30-2014, 5:35 PM
I had thought that the Viking sword maker was doing everything the right way,always only forging at a red hot temperature. That,and very high carbon steel was the secret of the ancient Wootz(Damascus) steel. When Europeans forged,they heated their steel to a much higher temperature,causing their carbides to melt and re form as large crystals. Forging at red heat caused the unmelted carbides to be crushed into tiny crystals,but was nearly as hard as forging cold steel for the blacksmith. It is these very small carbides in a soft matrix that give Wootz steel its ability to take a sharp edge and still be tough. Then,he heated the sword white hot to weld in his lettering(which did not really appear to be truly up to welding temp,as it was not sparkling hot),and would have ruined the carbide structure.

Then,the quench was way too small. The oil was boiling,and he took the blade out while it was still really hot. The quench should be large enough to not heat appreciably when an object is quenched. I am not sure how he imparted a spring temper into the sword,unless the hot withdrawal from the too small quench was supposed to automatically make a spring temper. It is not the usual way to go about hardening and tempering.

I am not sure the original sword had inlaid letters. They looked just chiseled out and left that way. If the Vikings had inlaid letters made of lower carbon steel,or wrought iron,they would not have corroded away as fast as the blade itself,and would still have been seen in the blade.

I don't know. Maybe there are things that are standard practice in sword making that are not employed in ordinary work.

Pat Barry
01-30-2014, 8:05 PM
To conclude this thread...
While grinding the plane blade down, I uncovered a defect (or two) in the blade. As I ground the blade down near my scribe line, I noticed a black smudge on the ground part of the blade. I assumed it was just metal filings and water, as I just quenched the blade. I made another pass and found the black spots still there. On closer inspection, they are voids in the hard layer of steel. I am making the assumption that these voids right at the base of the crack line, caused the fracture.


I would say this is a chicken and egg situation. My thought is the defect you found when grinding the blade is most likely due to the crack caused by hammering. Highly doubt that the steel just happened to have voids there before hand. My 2 cents obviously.

Wilbur Pan
01-30-2014, 8:40 PM
Hi Wilber,

I got it from a shop in Japan.

http://www2.odn.ne.jp/mandaraya/kashin.html

Did/do they ship to the U.S?


I would say this is a chicken and egg situation. My thought is the defect you found when grinding the blade is most likely due to the crack caused by hammering. Highly doubt that the steel just happened to have voids there before hand. My 2 cents obviously.

That is a good point. I’ve cracked one blade when tapping it out, to the point where I popped the chip completely out. I remember it leaving a jagged surface much like in David’s picture above.

Also, if those inclusions were there, by the location in the photo some sort of defect should be noticeable on the back of the plane blade.

Wilbur Pan
01-30-2014, 8:43 PM
For any one interested in the process of hand forging high quality steel blades (including making the steel from iron and carbon in an authentic duplication of an ancient furnace) (and modern laboratory authentication of the quality of the steel ) be sure to check out the Nova episode here (http://www.pbs.org/wgbh/nova/ancient/secrets-viking-sword.html).

Another Nova episode worth watching is here: http://www.pbs.org/wgbh/nova/ancient/secrets-samurai-sword.html

David Wong
01-30-2014, 9:19 PM
Did/do they ship to the U.S?



That is a good point. I’ve cracked one blade when tapping it out, to the point where I popped the chip completely out. I remember it leaving a jagged surface much like in David’s picture above.

Also, if those inclusions were there, by the location in the photo some sort of defect should be noticeable on the back of the plane blade.

The shop will ship to the US using EMS.

I tend to think the voids were present in the blade before my cracking it. You can see that the walls of the voids are black oxidized. I do not recall whether they were visible on the back of the blade.

Stanley Covington
01-31-2014, 7:48 AM
Everyone makes this mistake. From your picture, clearly the problem is improper support.

The important thing to keep in mind is that the purpose of the hammer strikes is not to bend the blade, but rather to deform the jigane (softer, low carbon steel layer). Each individual hammer strike deforms a little area of the jigane. After many blows, the accumulated deformation causes the jigane to expand. But at the same time, the high-carbon steel layer refuses to deform and expand, and the resulting stresses cause the blade to curve.

To effectively deform the jigane without cracking the HC steel layer, the specific spot on the bevel your hammer strikes each time must be supported on your rounded metal anvil surface and aligned PRECISELY where the hammer would strike the anvil if the blade was not there. This is absolutely critical. The commercial jig shown in the previous post ensures this precise alignment. Remember, you don't want to support the blade across its width on the anvil, but only where the hammer blow will fall. I imagine tapping a ball bearing welded to the anvil with my hammer. Some practice is helpful.

Make a hardwood practice piece approximately the same dimensions as your plane blade, including a bevel. Hold it lightly between thumb and forefinger, and rest it against the anvil, indexing against your forefinger so that the spot you intend to strike is in full contact, and not offset. If you have aligned the practice piece properly, and swing your hammer precisely, the hammer strike will not cause the piece to flip, or twist, or dance a jig, but it will just sit there while all the hammer's force goes directly through the wood, crushes some fibers on its way, and then flows into the anvil. It's a very stable feeling.

Use a rounded metal anvil surface. The corner of a vise rounded over with a file works well, but I have used a 5lb sledge as an anvil in a pinch. A bit of paper glued to the anvil makes for a softer surface that might help your control. Use a lightweight hammer with a smallish face: A tack hammer, or sawset hammer works well. A domed-face hammer won't.

I don't have time to talk about the strike pattern, other than to say most of your strikes should be focused on the center two thirds of the bevel, and well away from the HC steel cutting edge. Also, there is no point in striking either end of the bevel's width. It helps to draw an oval "strike zone" on the bevel using a marking pen to help focus your hammer strikes.

Get right on top of the anvil, and orient your wrist against your body to help maintain the length of the hammer's arc in perfect alignment with the strike point on the anvil so you don't inadvertently extend the hammer too far and chip a big piece out of the blade. Strike with the bottom edge of the hammer making little crescent indentations. Move the blade a little with every strike. Remember, you want the stresses distributed fairly evenly, so your strikes must be distributed in a regular pattern. Don't try to develop a rhythm yet: Make every strike precisely and deliberately, pausing between strikes. Speed will come with lots of practice. Check your progress frequently.

I hope this helps.

Stan

Stanley Covington
01-31-2014, 7:58 AM
Stan Covington mentioned that he had chipping problems with a mosaku plane that he got based on my comments, and I think he's cursed my plane, too!! The last time I used it, I had tiny chipping issues with it, and combined with its hardness, that can make for an undesirable session.

My experience with yamamotos (having had 3) is that they are somewhere between in hardness. They are not as hard as the mosaku iron, but the ones I had (not swedish) were not exactly soft, either.

Sorry to hear your Mosaku is misbehaving, David. Mine has settled down and is performing nicely. Bought a Keisaburo (Uchihashi san) plane a few weeks ago, and am very impressed. A bit pricey, but well made in every way. I think this younger smith has a bright future.

Stan

David Weaver
01-31-2014, 9:11 AM
Everyone makes this mistake. From your picture, clearly the problem is improper support.

The important thing to keep in mind is that the purpose of the hammer strikes is not to bend the blade, but rather to deform the jigane (softer, low carbon steel layer). Each individual hammer strike deforms a little area of the jigane. This accumulated deformation causes the jigane to expand. But the high-carbon steel layer refuses to deform and expand, and the resulting stresses cause the blade to curve.

But to effectively deform the jigane without cracking the HC steel layer, the blade must be supported on your rounded metal anvil surface and aligned PRECISELY where the hammer would strike if the blade was not there. This is absolutely critical. The commercial jig shown in the previous post ensures this precise alignment. Remember, you don't want to support the blade across its width on the anvil, but only where the hammer blow will fall. Some practice is helpful.

Make a hardwood practice piece approximately the same dimensions as your plane blade, and cut a bevel as well. Hold it lightly between thumb and forefinger, and rest it against the anvil indexing against your forefinger just where you intend to strike. If you are supporting the blade on the rounded anvil surface properly, the hammer strike will not cause the wood to flip, or twist, or dance a jig, but it will just sit there while all the hammer's force goes directly through the wood, crushes some fibers on its way, and then flows into the anvil. It's a very stable feeling.

I don't have time to talk about the strike pattern, other than to say most of your strikes should be on the center two thirds of the bevel, and well away from the HC steel cutting edge. Strike with the bottom edge of the hammer making little crescent indentations.

Use a rounded metal anvil surface. The corner of a vise rounded over with a file works well, but I have used a 5lb sledge as an anvil in a pinch. A bit of paper glued to the anvil makes for a softer surface that might help your control. Use a lightweight hammer: A tack hammer, or sawset hammer works well. Don't try to develop a rhythm yet: Make every strike precisely and deliberately, pausing between strikes. Speed will come with lots of practice.

I hope this helps.

Stan

Excellent and precise as usual, Stan. It's such a joy to read your posts.

Glad to hear your mosaku is settling down. I'm sure mine will, though back when I was accumulating japanese planes, I wish you'd have been around on the forums as I'd have half as many planes and they'd be twice as good.

Chris Griggs
01-31-2014, 11:59 AM
Excellent and precise as usual, Stan. It's such a joy to read your posts.


Indeed!

Stan!!!! My man! Where you been dude? We've missed you!

Stanley Covington
01-31-2014, 12:08 PM
Indeed!

Stan!!!! My man! Where you been dude? We've missed you!

Dude! Busy as a one-armed, one-legged, hung-over, paper hanger! Come to Kyoto, and I'll show you!

Chris Griggs
01-31-2014, 12:26 PM
Dude! Busy as a one-armed, one-legged, hung-over, paper hanger! Come to Kyoto, and I'll show you!

That's pretty darn busy! Always glad to have you pop up though.