Thomas Ascher

[Thomas Ascher]

Jose,
Congrats on your new possession. Sorry I haven’t posted photos. My camera is over 1,000 miles away! I’ll be gone for the summer. Maybe next year. Check out photos linked to other posts. I think you only begin to understand the HobbiGoni after you’ve used it on many knives, and especially at various stages of sharpening, or re-sharpening the same knife. It would be instructive to take a knife that’s been damaged or purposely dulled, then examine with the HobbiGoni at each stage of re-sharpening. Maybe next year when I have my HobbiGoni and camera and knives in the same place I’ll do! I don’t understand “measure each side independently”. The instrument shows both sides, one on each side of the scale so you can examine, compare each side.
Tom

[Thomas Ascher]

When you receive the HobbiGoni termed a “Laser Knife-Edge Protractor” you find an enclosed booklet of User Instructions. It shows diagrams and patterns of reflections from thin and thick knives, curved or hollow ground surfaces. The key item mentioned is that “the closer the reflection is to a full and bright dot the nearer the surface is to a perfect mirror polish.”

In my experience, I found that I needed to use the instrument on various knives, looking at various patterns to educate myself on what I was seeing and why. If I saw a bright dot on each side of the scale, I knew that I had achieved a flat, highly polished surface on each edge. If I found that I had more than one point, or an angled line, or a blurred, wide reflection, I knew that I had something less than perfection. Over time, comparing the reflections from the laser with what I was able to observe about the knife edge under a microscope, I’ve educated myself regarding what imperfections of sharpening technique correlate with what patterns of reflections in the HobbyGoni.

One of the surprising things I discovered was that a couple of Masamoto knives I had newly acquired from Japan, one an HC, the other a VG, had rather blurred, indistinct reflections when viewed with the HobbyGoni. My initial reaction was that the HobbyGoni was a rather crude, not very useful instrument. Over time, re-sharpening, polishing these knives, I achieved much more precise reflections with the HobbyGoni confirmed by real-world improvements in cutting performance.

[Thomas Ascher]

http://www.catra.org.uk/product_p/cuhg.htm

Sorry for the misspelling in the heading. Couldn’t find a way to edit after posting!

Tom

[Thomas Ascher]

There’s almost too much information, too much testing, too many photographs! I’m overwhelmed! Think I’ll get the leather strops and try the smallest pastes. It has so much to do with direction of movement, number of passes, technique! I’ll know more when I’ve gone back to the strops and try on my own. Thanks for the help, references, there’s really no lack of information on the forum! This really goes way beyond practicality. My knives are really sharp enough. But as a hobby, much fun and less expense than restoring classic cars or old homes… :cheer:

[Thomas Ascher]

What about after the micro-fine?

[Thomas Ascher]

Okay, maybe I’ll order a pair of leather strops again and give a try. Which strops and paste would you recommend once I finish with the micro-fine ceramics?

[Thomas Ascher]

Good suggestion where I find leather strops too difficult. Expensive, but maybe less hassle in the long run!

[Thomas Ascher]

I understand using leather strops on short knives using just up motion. On a 240mm Gyuto not so easy. Maybe I’ll look into using finer stones. Or just being satisfied to end with ceramics!

[Thomas Ascher]

I really like the Murray Carter video as it demonstrates difference before and after stropping. Can someone clarify for me what “stropping” might mean? I go as far as the extra fine and ultra fine ceramics. What is the next, “stropping” step? Could I get a barber’s strop and use that? What are my options? I tried the leather strops from WE but could never master. Always ended up slicing the strops to ribbons before I got very far with my knives! 🙁

[Thomas Ascher]

sub 20* inclusive angle?! Didn’t know such a thing exists! Where? I’ve sharpened my Gyutos to 12* degrees on each side for a 24* angle and even this I find hard to maintain without chipping!

[Thomas Ascher]

Yeah, the video of the Konosuke HD Gyuto is the kind of thing I’m talking about. I have a couple of Japanese Gyutos that I’ve polished with the WE ultra fine ceramics and come close to this, but not quite. The idea of polishing on newspaper is something I’ve not tried! Gives me something to aspire to. On the other hand, finding some truly ripe, juicy tomatoes might do the trick! 🙂

[Thomas Ascher]

Let me be sure what is being asked here. First, once the angle cube is laid flat on the base and zero’d I find that it will consistently read zero when re-placed in the same location. Now, when the cube is laid against either arm, then moved and replaced, readings can be expected to vary slightly. This is because the position of the cube on the arm can vary, the position of the arm on the knife edge can vary,and finally the pressure of the cube against the arm can vary. There is a slight give, or bending of the knife itself in response to pressure. In summary, a variance of a few tenths of a degree is nothing to be concerned about.

[Thomas Ascher]

One item not mentioned, which should be, is that the manner in which the vise clamps secure a blade vary depending upon how they are tightened. The WEPS needs an upgrade so it is possible to rotate a knife blade to achieve 90 degrees relative to the base every time. Otherwise, it is all too easy to have a degree or two of variance every time it is clamped into place. It doesn’t do much good to use a sharpee or angle cube to set the angle for the stones if it is not possible to control the angle of the knife itself.

[Thomas Ascher]

Doing much research on the internet, this is one of the most muddled topics I’ve seen! Many conflicting, contradictory explanations regarding the value of asymmetrical edges as well as the proper means of sharpening. The discussion so far seems good in that as indicated, asymmetry can be achieved either by having the same angle on each side, but the edge displaced one way or another, or the same displacement with different angles on each side. The best rationale I’ve seen is that with a very thin blade, having most of the sharpening on one side you can achieve a very thin, fine-cutting edge without losing so much metal on the other side that it is easily chipped.

The idea of a knife inherently being asymmetrical doesn’t seem to me to make much sense as you can order the same knife sharpened for either left or right-handed use.

I’d like to hear from people who have used a right-handed knife left-handed or right-handed or the reverse and know if they’ve actually experienced any difference in how it cuts.

[Thomas Ascher]

While we’re on the subject, I thought I’d clarify the need for the Angle Cube given that the WE sharpener already has a scale for angle adjustments. The scale is only approximate and needs to be compensated for depending on the width of the knife being sharpened and the thickness of stones. For example, with my chef’s knives which are about 2″ wide, the angles need compensation for the fact that the edge is higher above the clamp than on a narrower knife. Also, Chosera stones are thicker than the WE diamond stones. That changes the angle as well. So, My Shun chef’s knives have a factory edge of 16 degrees. Using the WE stones, I have to set the WE angle settings to 18 degrees to get 15.6 degrees as measured by the Angle Cube. When I switch to the Chosera stones, I have to move the WE settings to 20 degrees, again, to get 15.60 degrees.

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