'Touching up' an edge: when, how, and what to use

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d_rap
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Re: 'Touching up' an edge: when, how, and what to use

Post by d_rap »

Great perspective on thinning; thank you Joe.

Chappy, you've really opened up a couple key topics in this thread. I wanted to return to stropping/finishing on a high grit stone.

I know Grant mentions dry stropping above and Ourorboros said sure in response to your question this morning. And absolutely, a dry surface may deburr or remove traces of wire very effectively late in the game, and maybe better, under some circumstances than wet.

But I want to share something that has also worked very well for me lately that involves not just stropping on a wet 3-6K stone, but stropping on a stone with a fair amount of slurry into the bargain. The theory behind it (admittedly I just made this up) is that if leather works so well to finish it is partially because there is some give, or desired slight "inaccuracy" as an effect of softness. A leather, denim, etc. strop, with or without compound, is good because it is soft enough not to damage the almost finished edge and forgiving enough to delete imperfections that exist on either side of an imaginary straight line. Leather can be amazing late in the game precisely because of its pliability and slight imprecision.

So, in practice, let's say I have finished a knife on a 5K Rika, regular finish sharpening. Before proceeding I lap/flatten the stone (needs a touch up at this point anyway) and leave the slurry or mud from the lapping instead of rinsing or brushing it off. Not a big pile, but enough to get some slight give to the surface, emulating the effect you get with leather. The surface is damp, a bit muddy now by design, and in many cases I've found the perfect medium for high grit stone sharpening. Now I finish the knife on the same stone using all edge trailing/stropping strokes, moistening as I go. Works great with a softer soaker like a Rika, but also with a harder stone like an SG. I have gotten some really excellent results with this technique.

Of course there's nothing entirely new under the sun here. Everyone who sharpens seriously knows that it can frequently help to raise a slurry. What has been new for me is using my Atoma or cktg flattening plate specifically both to flatten and to dress a stone for stropping at the end of a session.

Not at all a diss of dry stropping on a high grit stone, but just another perspective, something to try that might work surprisingly well for at least some applications.
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Re: 'Touching up' an edge: when, how, and what to use

Post by Radar53 »

d_rap wrote: Mon Nov 30, 2020 4:27 pm What has been new for me is using my Atoma or cktg flattening plate specifically both to flatten and to dress a stone for stropping at the end of a session.
Not at all a diss of dry stropping on a high grit stone, but just another perspective, something to try that might work surprisingly well for at least some applications.
Yep totally agree when sharpening, and I'm really enjoying delving into the effects of "mud". But I'm a lazy bugger at times & if I'm simply looking for a light "refresh", that a strop is struggling to do, I want something quick & easy and use a ceramic rod most of the time. But I've been playing around with just grabbing a dry, fine stone, maybe less than half a dozen light strokes seems to do the trick. Effectively using it as a "flat" ceramic rod. Just checking it out for interest's sake.
Cheers Grant

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Re: 'Touching up' an edge: when, how, and what to use

Post by Chappychap »

Wow lots of interesting new info in this thread to find after finishing work today. Thanks all - time to experiment!
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Re: 'Touching up' an edge: when, how, and what to use

Post by David_R »

Great thread. A lot of experience being shared here. I like to strop to get my edge back newsprint cutting sharpness until that doesn't work or doesn't last long enough. Usually 1 micron strop on balsa or bass wood, but sometimes use leather as well.
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Re: 'Touching up' an edge: when, how, and what to use

Post by Chappychap »

Just a follow up to this thread to say thanks again for all the advice. It really helped me today when I was diagnoing my Masagake Koishi 150 petty today. Ended up dropping right down to 500 and putting a tiny burr on before removing and refining. Two things I learned today, in case helpful to others on thir sharpening journey:

1- Today I realised that my previous approach to feeling for a burr had been completely sub optimal. I was previously trying to feel it on the skin between thumb and finger, which I could only feel when the burr was frankly rather huge. I couldn’t figure out how people feel for the smallest of burrs (as referenced on this thread) until I tried the technique of trailing the edge backwards against my fingernail and feeling for that scratchy resistance feedback that indicated a burr was present. This was a game changer — it enabled me to a) take off far less metal and save time, and b) establish a more consistent burr, right to the tip. Glad I learned this relatively early on in my sharpening journey.
2- Using a high powered headlamp was incredibly useful as a secondary way to assess an edge, better than holding up to any static lights I had. Turns out the Petzl headlamp I use for walking the dogs has a second use! With the amount of light that put’s out it was so much easier to assess reflections caused by metal being out of line or in a burr — and then also to see when they were absent. A headlamp is my new favourite tool for making sharpening that little bit easier and more enjoyable.

For anyone interested this blog post covers some of the above and was extremely helpful today:

http://sharpener-pete.blogspot.com/2020 ... -them.html

For next time, I must remember to try raising a micro burr on each stone as Peter suggests. Now that I know the nail/burr detection trick, that level up in technique is within reach.

Also shout out to Mark at CKTG for his YouTube video on grip that popped up in my feed today. I thought I had this basic down already, but the video helped me refine the technique a bit, so I guess I didn’t! Much more consistent angle today as a result.

https://youtu.be/j5Zio0qRGaI
Last edited by Chappychap on Sat Jan 23, 2021 9:53 pm, edited 1 time in total.
d_rap
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Re: 'Touching up' an edge: when, how, and what to use

Post by d_rap »

Really feel you on feeling for a burr. Not even close to obvious. Fingernail, great suggestion, and for me everything bone dry, knife and fingers. Switching hands helps me too.

Another technique: having a perfectly clean, bone dry, fine microfiber cloth. Brush that up off the edge, with your fingers in the right position, and you can feel even a tiny burr. It's a slight catch. Switch sides and you'll feel the difference immediately.
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Re: 'Touching up' an edge: when, how, and what to use

Post by Chappychap »

That's a really great suggestion. Adding that to my notes to try for the next time. Thank you.

I also managed to sharpen my haircut scissors fit this first time due to this forum :)
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Re: 'Touching up' an edge: when, how, and what to use

Post by ronnie_suburban »

d_rap wrote: Sat Jan 23, 2021 8:33 pm Really feel you on feeling for a burr. Not even close to obvious. Fingernail, great suggestion, and for me everything bone dry, knife and fingers. Switching hands helps me too.

Another technique: having a perfectly clean, bone dry, fine microfiber cloth. Brush that up off the edge, with your fingers in the right position, and you can feel even a tiny burr. It's a slight catch. Switch sides and you'll feel the difference immediately.
I didn't come up with this on my own (in fact, I probably read it here somewhere) but I like to drag a q-tip along the edge of the blade. When the fibers from the swab catch, the burr is there.
=R=
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Re: 'Touching up' an edge: when, how, and what to use

Post by FisherMAn1298 »

Guys,read this article:
https://scienceofsharp.com/home/
Top
ON a shapton 320 it got a burr that had a small chip, it sharpened til he could cut paper. Then he did 10 leading stropping stroked on a s hapton 16k,
got rid of all the 320 scratches and wiped out part of the chip. after 90 more alternating leading strop strokes, no 320 scratches were there and the chip was gone. The data was arrived using cross sections from an electron microscope.
S I took mytw2-c161 tachikazi w #2 which I could cut paper ok, I did 10 LEADING EDGE strops on each side and I could cut paper VERTICALLY and horizontally cut the paper silently and so smoothly. The difference from stropping with a leading edge stroke was immense. I still haven't read all the chapters in that paper. Check it out guys, it'll change the game for you. I have shapton glass 500,2k and 4k. Was gonna add 8k or 16k, now I'm thinking adding 1k, then just working like hell on angle, hand placement and consistency of stroke. Also, I will do half trailing edge strops and finish with leading edge strops. I still can't believe what it did to my blade. When I ran it over my finger nail I felt NOTHING! smooth as silk, never had that before. Let me know what you guys all think after you READ the article and try it.
YOu just want to touch up a knife, as many leading edge strokes as you want. Also, I took a brand new leather strop, sprayed it with .125 micron spray, then sprinkled aluminum oxide powder on it and rubbed it in. 5 strops on a knife already sharpened, OMG!
Talk to me, guys. Tell me if you find the same results from all this.
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Re: 'Touching up' an edge: when, how, and what to use

Post by Eli Chaps »

Todd does great work for sure but it is also important to read the comments below his posts. It brings a lot of insight beyond the initial presentation. If I remember right, in those comments he also says he actually prefers just using edge trailing on a strop.

But, that said, I always do a few edge leading strokes side-to-side before deburring with edge trailing both on the stone and then deburring lightly on a strop.
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Re: 'Touching up' an edge: when, how, and what to use

Post by Chappychap »

Separately, finally got round to trying one of Ken's nano cloth strops today. Wow! What a quality product. Love the solid construction and backing. It brought my Kono SKD right bank to life. Looking forward to trying it with the 0.75 micron compound.
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Re: 'Touching up' an edge: when, how, and what to use

Post by Chappychap »

d_rap wrote: Sat Jan 23, 2021 8:33 pm Another technique: having a perfectly clean, bone dry, fine microfiber cloth. Brush that up off the edge, with your fingers in the right position, and you can feel even a tiny burr. It's a slight catch. Switch sides and you'll feel the difference immediately.
Testing continued tonight as it was takeout night and so wasn't cooking. Sharpened up the Wustoff paring Mrs. Chappy uses all the time.

The above technique was really useful. Thank you. Another that I discovered tonight was shining a light behind the edge, which allows you to see the tiniest of burrs. You can see a hairline of light reflection along the edge with the burr, and much more clearly see the spots you need to work on further without the reflection. The combination of this and the above enabled me to up my game significantly tonight, making sure I was getting to the edge of the edge with each stone.

Good discussion on this thread about the light trick, in case it helps anyone else: https://www.bladeforums.com/threads/rea ... 162/page-2
755581E7-1611-4AC8-BF5E-A872E127DD70.jpeg

Can't help but be slightly frustrated that none of my knives are dull right now. I can't wait to see how sharp I can get a higher quality knife with these techniques. Clearly need to be cooking even more to wear them down. :lol:.
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