-
The BladeForums.com 2024 Traditional Knife is ready to order! See this thread for details: https://www.bladeforums.com/threads/bladeforums-2024-traditional-knife.2003187/
Price is $300 ea (shipped within CONUS). If you live outside the US, I will contact you after your order for extra shipping charges.
Order here: https://www.bladeforums.com/help/2024-traditional/ - Order as many as you like, we have plenty.
Cliff Stamp on Destressing Edge
- Thread starter 4th. Down
- Start date
- Joined
- Apr 12, 2009
- Messages
- 13,390
If I recall, 'destressing the edge' is all about lightly grinding the apex off, by drawing the edge across a stone with the blade held perpendicular to the surface of the stone.
Assuming that's the case, the resulting apex will be flattened across its width somewhat, and therefore will reflect a visible 'thread' of light along the edge. Finishing the edge after that is all about narrowing the apex again, by regrinding the bevels from each side, until the two bevels intersect completely at such a narrow apex width that the apex will no longer reflect visible light.
Put more simply: Grind the bevels until the apex is at such a fine 'point' (in cross-section), that you can no longer see any light reflected from it while looking directly into the edge with a light source directly above it. This is where the apex will be as sharp as it can be, and cutting tests will prove that out.
Assuming that's the case, the resulting apex will be flattened across its width somewhat, and therefore will reflect a visible 'thread' of light along the edge. Finishing the edge after that is all about narrowing the apex again, by regrinding the bevels from each side, until the two bevels intersect completely at such a narrow apex width that the apex will no longer reflect visible light.
Put more simply: Grind the bevels until the apex is at such a fine 'point' (in cross-section), that you can no longer see any light reflected from it while looking directly into the edge with a light source directly above it. This is where the apex will be as sharp as it can be, and cutting tests will prove that out.
Last edited:
- Joined
- Jul 14, 2017
- Messages
- 586
Not sure why but the video seems out of sync for me. Basically what David said, Cliff was a big fan of micro bevels and that was the last step of this process, slightly increasing the angle using very light force.
- Joined
- Apr 12, 2009
- Messages
- 13,390
A microbevel is a quicker way to narrowing the apex, once the steel behind the edge is thinned out sufficiently. The microbevel adds some strength and stability to the edge as well. If I recall, Cliff likes to grind edges very, very thin. An edge can be very fragile at such thinness - so the micro can bolster the edge a bit. I used to not microbevel my edges. But I'm finding some value in it these days, when done very, very minimally in maybe one or two passes per side at the lightest possible touch.
- Joined
- Mar 8, 2008
- Messages
- 25,892
Cliff's "destress the edge" step was the removal of any material at the very apex of the previous worn edge that had been fatigued from use, which prevented small fractures that could otherwise occur along the edge and result in more rapid dulling. Doing a couple of light cuts perpendicular to the stone was all it took to remove the small amount of affected material.
- Joined
- Apr 12, 2009
- Messages
- 13,390
The reflectivity of light from the apex is of some value in sharpening, because it's realistically possible to thin the apex to something thinner than the wavelength of visible light. Visible light's wavelength, as can be detected by the human eye, is in the 380-700 nanometer range. In the micron-unit terminology we often use in sharpening, that'd be about 0.38 - 0.7 microns. A well-honed edge for shaving is usually assumed to be somewhere in the 0.5-micron (500 nanometer) or thinner ballpark. So, if the edge is truly thin enough to not be seen by the naked eye in good lighting, it can be assumed to be a very keen edge.
- Joined
- Apr 12, 2009
- Messages
- 13,390
Completely agree. I knew many shaving edges on true razors were at least down around 0.2 micron or so. So that doesn't surprise me at all. But that's why I included 'or thinner' in my own earlier reply. I sort of recognize something around 0.5 micron on an EDC blade as beginning to shave decently for such a blade, albeit not like a true razor.
- Joined
- Sep 3, 2006
- Messages
- 3,131
- Joined
- Mar 8, 2008
- Messages
- 25,892
Yeah a while ago. Was very sad news.
6/21 @ 47......he was a good one...very good to the blade community.
cudgee
Gold Member
- Joined
- May 13, 2019
- Messages
- 7,672
- Joined
- Jan 9, 2006
- Messages
- 9,684
Yes, at the very end, a few passes on each side for ultra sharpness. In the video he continued to use a low grit splash water stone and finished with it. What a guy and ultra sharing with us for no $$$$ back to him.
- Joined
- May 25, 2007
- Messages
- 1,157
Looks like in the last few months/years he devoted his life as a volunteer for a good cause instead of "chasing the edge". Sad to see that knowledge pass away.
Yeah, destressing just means cutting the tired steel with a couple of light cuts straight into the stone.
The idea with his "plateau sharpening" method is to form the bevel until it doesn't reflect any light, but before you form a burr. Then use very light passes to refine it to a cutting apex. This way you have minimal stressed steel at the apex. It's easier if you increase the angle slightly at that point, and after that lower it to blend the bevel/micro-bevel. Again, very light pressure. This method is fast, allows you to not muck about with burr removal - have a more durable cutting edge, and produces consistent results with different steels.
The idea with his "plateau sharpening" method is to form the bevel until it doesn't reflect any light, but before you form a burr. Then use very light passes to refine it to a cutting apex. This way you have minimal stressed steel at the apex. It's easier if you increase the angle slightly at that point, and after that lower it to blend the bevel/micro-bevel. Again, very light pressure. This method is fast, allows you to not muck about with burr removal - have a more durable cutting edge, and produces consistent results with different steels.
- Joined
- Mar 22, 2014
- Messages
- 5,357
Seems there is always going to be some burr in practice, however small burrs are more manageable.
FortyTwoBlades
Bravo, excellent description.
RIP Cliff.
Perhaps. But if you can cut it off after making one, you should be able to cut it off as it forms. Only a microscope will tellSeems there is always going to be some burr in practice, however small burrs are more manageable.
Bravo, excellent description.
RIP Cliff.
In any case, it makes sense trying to not make them, minimize them.