Coarse edge with a little stropping
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- This topic has 39 replies, 13 voices, and was last updated 04/07/2015 at 8:15 pm by Aaron kimpton.
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03/17/2015 at 9:26 pm #24402
Lately I’ve been playing around with some different edges and it’s been really instructive. Hopefully we’ll get our new sharpness testing machine built soon so we can gather some empirical data. In the meantime, it’s been great to just change up my carry knife to get a sense of how things are working. My latest setup is the following:
I thin the edge down to something pretty acute like 15° per side. I work through all the grits I want until I get a polish I like. Then I add in a micro-bevel at 4°-5° per side wider, in this example 20° per side. I do this with only a few light strokes with the 200# stones. After the stones, I lower the angle back to 15° and do a few very light strokes with my strops.
I’m enjoying this kind of edge because it slices very well, very aggressively through tough and/or fibrous material. It shaves easily and push cuts copy paper. I haven’t tested to see if it push cuts anything else yet. It fees dangerously sharp using Murray Carter’s 3 Finger Test. Touching up is a breeze, needing only one or two strokes per side with the 200# stones at 20°, a couple of strokes with the strops if desired. It’s a great looking edge, the micro-bevel being almost invisible so you see the highly polished primary bevel.
Has anyone else been playing with an edge setup like this?
-Clay
03/17/2015 at 11:00 pm #24409Yes, I have! But I haven’t gone down to the 200s to micro-bevel. My rationale was based upon all that I’ve been learning about the geometry of Japanese kitchen knives and how every facet of the overall sharpening process seems to have a specific end function in mind. Also, the notion that the relief bevel is the most important part in “slicability” because less friction takes place between the blade road and the material being cut (among a few other reasons)… But, what if you don’t have the option on a wide relief, say on an EDC? Can you accomplish the same idea by creating a super polished secondary bevel done at a reasonably low dps that reduces friction, and, at the same time, create a micro-bevel for a more aggressive cutting edge that holds up to the task at hand?
Clay, I’d definitely be interested in some magnifyied images of the edge polished at 15dps with 200 grit 20dps micro-bevel if you have the time!
03/17/2015 at 11:09 pm #24410very interesting clay! I have tried similar but only down to 400 grit. I will def. have to try that though!
03/17/2015 at 11:17 pm #24412Clay,
Since you posted the link to the science of sharp:
https://knife.wickededgeusa.com/forum/11-thoughts-theories-science-related-to-sharpening/13485-more-sem-images-from-the-science-of-sharp
I thought about it for a bit and sharpened my Zero Tolerance 0801 in similar fashion; thinned and polished to 17 degrees per side, stropped at 15 degrees followed with two strokes of the 400 diamond per side at 20 degrees. I didn’t follow up with further stropping like you mentioned, but the results are striking compared to some other methods I have used. I chose the 400 grit mainly from the video and my 400 is broken in more than the coarser diamonds.
Then I did the same on another Elmax knife and a S30V both with the final bevel at 21 degrees.
I use the S30V Blur for all sorts of nasty jobs like scraping old caulk out and this method seems to stay sharp better than the previous method of thinning at 20 degrees and final bevel at 22 degrees with the 1000 grit diamond.
Thanks Clay for your continued enlightenment. There is no better education on sharpening than this forum. I’ve come to realize that the definition of sharp is as varied as to the material being cut and who is doing the cutting; there is no perfect sharp that we all keep striving to attain.
–Gregg03/17/2015 at 11:42 pm #24414Thanks for that Clay. Yep, been playing with 5 degrees, actually the 15/20 combo exactly, but like the others have not dared to just hold at 200 or 400 for the micro. wow. I’ve only gone as low as 800. I must try to be more creative and try/experiment with these things… especially after reading that recent Science of Sharp post.
“Thanks Clay for your continued enlightenment. There is no better education on sharpening than this forum. I’ve come to realize that the definition of sharp is as varied as to the material being cut and who is doing the cutting; there is no perfect sharp that we all keep striving to attain. –Gregg”
yep – bingo – the fun is trying to… regardless.
03/18/2015 at 1:40 am #24427Here are a couple of hasty shots of the edge on my ZT 0770:
The second one is taken through my loupe so you can see the micro-bevel better. I haven’t gone for a true mirror here, just a fast progression through the stones and strops to 3.5 microns.
Attachments:-Clay
03/18/2015 at 2:22 am #24429Ah, very very nice. The 200 grit micro-bevel is crystal clear. Thanks Clay!
~Steven
03/18/2015 at 2:51 am #24432Outstanding! I never woulda thunk it. Which is why this forum is so goldarn fascinating. Every week there’s at least one forehead-slapping post by one of you – Doh!
03/18/2015 at 3:13 am #24433One of the most rewarding things for me of working with the jig is that I can do this kind of customized edge very precisely. If I wanted to refine that micro-bevel, just a few strokes with a fine stone would do it. Conversely, I could have begun with a very fine micro-bevel and made it increasingly coarse after using it a bit. Lots of fun.
Maybe some others would like to take up the challenge – sharpen at a low angle and polish the bevels. Then add a fine micro-bevel. Create some sort of easy cutting test like cutting a piece of rope on while it’s on a cutting board on a scale for example. Use the knife that way for a little, then go back and redo the micro-bevel with a stone one grit coarser than the last. Continue doing that until you’ve got the edge you love best.
-Clay
03/18/2015 at 4:15 am #24439Here is a Spydeco with the 1600 stones and a 1000 grit micro bevel. At 80x
[Img]http://www.pbase.com/dsgrouse/image/159234644.jpg[/img]
03/18/2015 at 8:51 am #24447Clay,
Since you posted the link to the science of sharp:
https://knife.wickededgeusa.com/forum/11-thoughts-theories-science-related-to-sharpening/13485-more-sem-images-from-the-science-of-sharp
I thought about it for a bit and sharpened my Zero Tolerance 0801 in similar fashion; thinned and polished to 17 degrees per side, stropped at 15 degrees followed with two strokes of the 400 diamond per side at 20 degrees. I didn’t follow up with further stropping like you mentioned, but the results are striking compared to some other methods I have used. I chose the 400 grit mainly from the video and my 400 is broken in more than the coarser diamonds.
Then I did the same on another Elmax knife and a S30V both with the final bevel at 21 degrees.
I use the S30V Blur for all sorts of nasty jobs like scraping old caulk out and this method seems to stay sharp better than the previous method of thinning at 20 degrees and final bevel at 22 degrees with the 1000 grit diamond.
Thanks Clay for your continued enlightenment. There is no better education on sharpening than this forum. I’ve come to realize that the definition of sharp is as varied as to the material being cut and who is doing the cutting; there is no perfect sharp that we all keep striving to attain.
–GreggGregg, this may or may not be of interest to you… but Cliff Stamp that has done some work showing that when cutting softer materials at least edge retention increases as your edge angle decreases until you hit the cross over point where it is too weak. most people sharpen way more obtuse than they need to and are not optimizing the edge retention capabilities of their knife.
03/18/2015 at 11:35 am #24448This is very interesting, I’d like to give it a try.
A newbie question though – when applying the micro bevel do you use edge trailing or edge leading strokes? Does it make a difference?Also, thanks for these types of threads! This forum has been invaluable to me as a new user.
03/18/2015 at 12:24 pm #24449Honzi:
Wish I could give you a definite answer on that, but I don’t think there is one. I’ve done it both ways and they both seem to work.
I’ve read elsewhere here that there is a difference in the direction of your micro-bevel (or final) strokes, depending on whether the user prefers to use the knife pulling or pushing through the veggies or whatever. A heel-to-tip down-stroke will produce “teeth” which will cut better in a pull cut rather than an away cut. Of course, the opposite applies for a user who prefers to slice away from him. Methinks it takes a very well-tuned user to feel the difference.
It seems intuitive to me that trailing-edge strokes would leave a more pronounced tooth than leading-edge strokes. I hope I’m not wrong on that. I’ve been known to be wrong at 3:00 AM.
With that, I think I shall hit the rack.
03/19/2015 at 1:40 am #24465I’ve never really noticed too much difference. Orienting the “teeth” in the direction towards the tip is what I go with because I’m the most comfortable with the natural motion of the stones which is up and away from me. At least it’s natural to me.
I have occasionally brought the strops up and towards me before, but I can’t do this very well in a light and consistent matter with my stones judging on a magnified look at my edge plus how it feels to me. I’ve not tried this yet with the longer arms from Oldawan, but I suspect I’d have better luck with the longer arms.
A lot of people assume that the natural cutting motion with a knife is a slice pulling the knife towards you or in a motion where the tip of the knife follows the handle. The majority of my cutting needs and uses is processing heavy cardboard boxes (not in my job but we just accumulate a lot of them at home) for easier disposal and because it’s fun trying different knives and edge combinations. My natural motion is to brace the cardboard edge on the counter or floor and push downwards with the knife tip staying pointed towards the floor in the entire motion. The tip to belly portion of the knife starts the cut, and the belly to heel finish it. All of my knives done on the WEPS breeze through cardboard this way so I actually find it advantageous to finish my knives this way.
IMO I don’t think it makes a huge difference but who knows. When making tip trailing slicing motions on plastic wrap or cellophane or phone book paper I don’t have any issues either. Just my 2 cents.
03/19/2015 at 11:43 am #24480Just happened to have my para 2 up on the blocks for a tune up so decided to give the coarse edge a try:
Primary bevel set at 12dps, kicked it out to 15dps with 200 grit for 5 light passes. Bevel is 2mm top to bottom…
I had the same initial results as Clay 100%, grabs hard at the finger pads with light touch and still would slice but not push cut phonebook paper. :blink:
There have been so many things going on in sharpening lately, SEM tests, Cliff Stamps field tests…I personally am also very excited to see/experience the results of a real world testing jig.
On a final note for the Para 2 s30v. I had it at something like 10 dps and it failed under medium use. The edge rolled just a bit… :whistle:
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