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Thread: Pm-v11 at 20*

  1. #16
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    Can someone start a unicorn thread here. Fascinating. I need to unlearn (and learn) some things.
    Last edited by Todd Zucker; 07-29-2020 at 8:51 AM.

  2. #17
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    Quote Originally Posted by Todd Zucker View Post
    Can someone start a unicorn thread here. Fascinating. I need to unlearn (and learn) some things.
    First watch David's first video: https://www.youtube.com/watch?v=Do7FdOh6S9s

    The following is a post I wrote at WoodCentral ...

    There has been a great deal of interesting photography of buffed edges to date. I don't have the microscope to add to this, and so I will just take what has already been presented that provides evidence of enduring edges. Edges which last longer are lovely, but ...


    ... I want the edges also to be sharp and take the type of shavings that are evidence of a working tool, not just a long-lasting, but dull-ish edge. Rounded edges increase the cutting angles from 20/25 degrees to 40-ish degrees? I mean, chisels are not expected to act like BU planes, are they? Or the scraping chisel of Bill Carter?


    Then I sharpened a chisel. Not just any chisel, but a Marples Boxwood with a 20 degree bevel. Actually, 5 of them. I wasn't in my right mind when I hollow ground them to 20 degrees - thinking that I could do with a few chisels with low cutting angles for dovetails - especially when they struggled to hold an edge at 25 degrees!


    And the new buffed edge? Well, it took amazing shavings. Amazing! And it did not stop taking these amazing shavings .... which is a miracle, since the blades of these chisels are made of cheese.


    They looked like this .. unfortunately not the Marples, but a Stanley #60 chisel (we all have a few of these for opening paint cans). The wood is Tasmanian Oak (similar to White Oak) ...




    Sharpening system? Nothing much. I had a much used 6" stitched mop soaked in Lee Valley green compound. This was chucked into my lathe ...





    The wheel was spun at 1450 rpm, which is the speed of a half-speed bench grinder in Australia. I use an 8" half speed bench grinder to hollow grind blades, so it made sense to use the same speed.


    The bevel was presented to the spinning mop and angled about 10 degrees (please note, if you are reading about this method for the first time, that the mop is spinning away from the edge).





    This resulted in a fine wire, and rather than buffing this off on the mop as David has done, I wiped the back of the blade on a section of hardwood with green compound.


    Having satisfied my self several times over that this method worked, and that it looked a Good Thing, I decided to purchase another grinder rather rely on the lathe .








    I got to thinking about trying this out on plane blades. In fact, I did so, and realised that it may not be a good idea. All the bench plane blades I have are cambered. Planing with a buffed cambered blade created shavings that were stringy, indicating an uneven edge. You can get away with this in a chisel, but not a plane blade. I shall try again, but that is my initial observation.


    I also tried this with block plane blades. Now this was different: 25 degree straight bevel, just like a chisel. But would it cut differently, especially on end grain where low cutting angles are expected to rule?


    A LN blade was hollow ground at 25 degrees, and then went through a typical process of extra fine diamond stone/Medium and Ultra Fine Spyderco ceramic stones, and a final polish on green compound-on-hard wood. At least the green compound would be the unifying medium.




    The surface/shaving on Jacaranda (the softest wood to hand) looked like this ...




    The buffed edge looked like this ...




    The buffed edge felt sharper and left a cleaner surface.


    This was repeated on Jarrah end grain. First the honed blade ...



    .. and the buffed edge ...


    Nothing in the two? If so, that is a win.


    Regards from Perth


    Derek

  3. #18
    Derek,

    I've just started reading about this and as always there are questions but I can also accept that it may be valid for no other reason than I've maintained forever that the important action with respect to cutters is not just the acuteness of the edge but equally the smoothness of the cutting edge (smoothing and decreasing the size of the saw teeth). From my experience a stropped edge will cut smoother and last longer than one not stropped. And BTW, I've never seen the effect of dubbing the edge, I'm sure it can be done, but. Of course you run into a problem with Japanese cutters if you wish to have a pretty bevel with a good difference between hard steel and soft iron, the strop destroys the difference Could be a small price to pay.

    ken

  4. #19
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    BTW, I've never seen the effect of dubbing the edge,
    A few careful strokes on a strop isn't likely to cause dubbing. A lot of strokes, especially carelessly done is likely to round an edge.

    Pressing down hard on the bevel while drawing it across a leather strop will compress the strop. The decompression action takes place right on the edge.

    Using hardwood for a stropping surface may help to prevent this action.

    My casual research on this was done by testing the blade off of the stones and then testing after stropping.

    If an edge indicated a 'toothy' blade fresh off a polishing stone it usually could be improved by stropping. It could also be improved by a bit more work on the polishing stone.

    A 'toothy' edge is one that catches hair when shaving.

    A fine keen edge straight off a polishing stone didn't have much improvement after careful stropping. It was possible to dub the edge if the stropping was excessive or wasn't performed with care.

    What this tells me is in the absence of a fine honing stone stropping can improve the edge, possibly substantially.

    jtk
    Last edited by Jim Koepke; 07-29-2020 at 2:13 PM. Reason: added; Using hardwood, was excessive or & rearranged wording
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  5. #20
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    Any way that produces results you can use the results of is fine. That line up the wall behind Derek's buffer wheel is the reason I can't use that method in the old houses I work on. The same for almost any kind of grinding, and especially dry grinding, even with a CBN wheel.

  6. #21
    Derek,

    "...Then I sharpened a chisel. Not just any chisel, but a Marples Boxwood with a 20 degree bevel. Actually, 5 of them. I wasn't in my right mind when I hollow ground them to 20 degrees - thinking that I could do with a few chisels with low cutting angles for dovetails - especially when they struggled to hold an edge at 25 degrees!

    And the new buffed edge? Well, it took amazing shavings. Amazing! And it did not stop taking these amazing shavings .... which is a miracle, since the blades of these chisels are made of cheese..."

    Just a question: Were your Marples chisels post 1933? In the photo the Marples chisels in the background are blurry and I can not see if the tangs are flat or round. My experience with flat tanged Marples is the steel is very good.

    BTW, all of this is very interesting. While it doesn't change my thinking about the importance of the condition/smoothness of the very edge of the cutter it may change how I get there.

    ken

    ken

  7. #22
    Quote Originally Posted by Jim Koepke View Post
    A few careful strokes on a strop isn't likely to cause dubbing. A lot of strokes, especially carelessly done is likely to round an edge.

    Pressing down hard on the bevel while drawing it across a leather strop will compress the strop. The decompression action takes place right on the edge.
    This is the conventional wisdom on stropping. I admit I've never done a thorough investigation of the subject. But the numerous tests done by David Weaver and Winston Chang suggest the conventional wisdom is flat out wrong, whether the stropping is done manually, or with a cotton buffing wheel.
    My advice to anyone who's interested: Read the threads on Wood Central, make sure you understand what is going on, then experiment yourself. Don't assume what you've previously believed is true.
    For two decades, I believed the conventional wisdom on cap irons. But in 2012-2013, I became convinced that the conventional wisdom was wrong. Most of the convincing happened on Wood Central and was spearheaded by a group that included the aforementioned Mr. Weaver.
    Another guy who was part of the group investigating the cap iron is Bill Tindall. Bill said to me the other day that it's hard to change, especially if you're already doing something that's successful. And he's right. But keeping an open mind, continuing to experiment and try new things, is a good way to avoid stagnation.
    "For me, chairs and chairmaking are a means to an end. My real goal is to spend my days in a quiet, dustless shop doing hand work on an object that is beautiful, useful and fun to make." --Peter Galbert

  8. #23
    Quote Originally Posted by Steve Voigt View Post
    This is the conventional wisdom on stropping. I admit I've never done a thorough investigation of the subject. But the numerous tests done by David Weaver and Winston Chang suggest the conventional wisdom is flat out wrong, whether the stropping is done manually, or with a cotton buffing wheel.
    My advice to anyone who's interested: Read the threads on Wood Central, make sure you understand what is going on, then experiment yourself. Don't assume what you've previously believed is true.
    For two decades, I believed the conventional wisdom on cap irons. But in 2012-2013, I became convinced that the conventional wisdom was wrong. Most of the convincing happened on Wood Central and was spearheaded by a group that included the aforementioned Mr. Weaver.
    Another guy who was part of the group investigating the cap iron is Bill Tindall. Bill said to me the other day that it's hard to change, especially if you're already doing something that's successful. And he's right. But keeping an open mind, continuing to experiment and try new things, is a good way to avoid stagnation.
    Steve,

    As Artie Johnson would say, very interesting. I've just started reading the threads so my take may be wrong but it may turn out that Paul Sellers isn't a joke after all. Correct me if I'm wrong but one test that has been done is stropping at ~45* angle with good results. If that is the case the dubbing problem can go the way of the tight mouth along some with other conventions of the world of wood.

    ken

  9. #24
    Quote Originally Posted by Steve Voigt View Post
    My advice to anyone who's interested: Read the threads on Wood Central, make sure you understand what is going on, then experiment yourself. Don't assume what you've previously believed is true.
    This is great advice.


    Quote Originally Posted by ken hatch View Post
    Correct me if I'm wrong but one test that has been done is stropping at ~45* angle with good results. If that is the case the dubbing problem can go the way of the tight mouth along some with other conventions of the world of wood.
    That's right (I'm the one who did that test). I've had a charged strop for a while, but I generally avoided using it because of the possibility of a dubbed edge. What I didn't ask back then was, what effect, exactly, would a dubbed edge have? Now I ask myself, why did I assume it would be a bad thing?

  10. #25
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    Here is a picture of a Marples chisel (Boxwood handled bought new in 1970's)windows e 009 (800x600).jpgwindows e 010 (800x600).jpg, at 20 degrees, rolling up shavings of fine toothed backsaw ridges left on small tenon cheek offcuts. The offcut is from window sash rails, so not very big. The light colored shaving in the background is from a block plane. This was a job to make 38 reproduction window sash for an 18th Century house, that were exact reproductions of the one original left. No sharpening was needed beyond what was done at the beginning of that job, and I don't want to count how many mortises, and tenons were cut, but every intersection of parts had them. The wood is very old, reclaimed Heart Pine of Southern Longleaf Pine.

    I don't own any PM-v11 steel, so sorry no help with the original question.

    I'll find some other pictures of Stanley no. 40 (the modern kind from the '80's with black plastic handles) that are kept at 18 degrees for jobs other than woodworking. We use sharp chisels for many more things than woodworking.

  11. #26
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    Stanley no. 40 at 18 degrees. Some more of other uses somewhere, but I'm not sure if I can find them. I feel like I can get these sharper than any other cutting edges I own, but I don't own any fancy, new ones. These are probably the newest chisels I own.
    Attached Images Attached Images
    Last edited by Tom M King; 07-29-2020 at 4:42 PM.

  12. #27
    Quote Originally Posted by ken hatch View Post
    Steve,

    As Artie Johnson would say, very interesting. I've just started reading the threads so my take may be wrong but it may turn out that Paul Sellers isn't a joke after all. Correct me if I'm wrong but one test that has been done is stropping at ~45* angle with good results. If that is the case the dubbing problem can go the way of the tight mouth along some with other conventions of the world of wood.

    ken

    Hey Ken,
    I'd never say P.S. is a joke, though I'm not a huge fan either. But more to the point, the "unicorn" seems to me to have some key differences from Sellers's method. His is a smooth convex curve along the whole length of the bevel, maybe 3/8" or so depending on the thickness of the steel. The convexity Dave and Winston are describing is happening over something like .005", and if there is a steep (e.g. 45°) angle at the tip, it's only in the final couple thousandths.
    "For me, chairs and chairmaking are a means to an end. My real goal is to spend my days in a quiet, dustless shop doing hand work on an object that is beautiful, useful and fun to make." --Peter Galbert

  13. #28
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    Quote Originally Posted by ken hatch View Post
    Steve,

    As Artie Johnson would say, very interesting. I've just started reading the threads so my take may be wrong but it may turn out that Paul Sellers isn't a joke after all. Correct me if I'm wrong but one test that has been done is stropping at ~45* angle with good results. If that is the case the dubbing problem can go the way of the tight mouth along some with other conventions of the world of wood.

    ken
    Ken, Sellers’ technique may resemble the rounded, buffed edge of the “Unicorn” micro bevel, but it is not the same at all. He is not rounding and increasing the angle at the micro edge; he is simply working the full face of the bevel in a curved action. He takes care to avoid lifting beyond (say) 30 degrees at the edge.

    Regards from Perth

    Derek

  14. #29
    Quote Originally Posted by Winston Chang View Post
    This is great advice.




    That's right (I'm the one who did that test). I've had a charged strop for a while, but I generally avoided using it because of the possibility of a dubbed edge. What I didn't ask back then was, what effect, exactly, would a dubbed edge have? Now I ask myself, why did I assume it would be a bad thing?
    Winston,

    Thanks, That is what I thought I understood. Good work.

    ken

  15. #30
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    This finally feels like the old days. Everyone is dead wrong, and everyone is dead right, about sharpening (chisels at least). I am excited. Maybe we can unify the field.

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