Edge Pro sharpening (being updated occasionally, July 2020)

Yeah, I am still in the OCD phase and don't know how long it would continue......


Miso
 
miso2 said:
Yeah, I am still in the OCD phase and don't know how long it would continue......


Miso
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Oh yah, enjoy the dark side. I used to go regularly to a hair salon near our house to collect some hair. The hairs I could harvest from my wife's hairbrush weren't enough for my hair whittling activities. I also had to explain to the salon owner why I needed hair. They thought I was going to use it for witchcraft or some such. :)
 
Oh, please! I got a visual of a guy with a knife on his hand crouching down on the floor to inspect a bunch of hair at a hair salon. Maybe whittle one or two while stared by a herd of hairdressers and female customers on the chairs.

But to be honest, I do collect my wife's hair and my 11 yo son's (and mine as well). I found that it is much more difficult to whittle my son's hair and use it for testing. What a gross hobby sometimes...... Definitely a dark side of it......


Miso
 
miso2 said:
Oh, please! I got a visual of a guy with a knife on his hand crouching down on the floor to inspect a bunch of hair at a hair salon. Maybe whittle one or two while stared by a herd of hairdressers and female customers on the chairs.

But to be honest, I do collect my wife's hair and my 11 yo son's (and mine as well). I found that it is much more difficult to whittle my son's hair and use it for testing. What a gross hobby sometimes...... Definitely a dark side of it......


Miso
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Fine hairs are definitely harder to whittle. We used to call ourselves(sharpness ocd's) dark siders before. The dark side was the pursuit of the ultimate sharpness. I don't have an idea if the term is still in vogue these days. Anyway, trying to improve skills and tools is always a positive for me, especially the skills part. Although a hair whittling edge is not much use, it is fun learning to get them. We used to argue before about hair whittling edges with some guys saying the pursuit was useless. I looked at it as an exercise in sharpening skill. If you can get there, then you obviously know how to shape an apex and remove a burr.
 
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Damn.. And I thought I went far with my sharpening... Seems not... Also on a side note I will go back to my 3d printed edge pro clone with dmt diamond plates (th one for the aligner kit). Then add strop to it as a final step. I have them all the way up to extra fine.
Didn't warm up to my complete set of Naniwa specialty stones and free handing. So sold them again. Maybe I should have cut the apart to use with the edge pro clone.
Personally I feel like the stability of the guided sharpening helps me more than the sharpening medium I choose.

Gesendet von meinem SM-A310F mit Tapatalk
 
Little update on PSI International.
I tried to make an account on their page, but instead of approving it, they told me that there is a local distributor in Japan. I will try to contact the distributor......


Miso
 
singularity35 said:
I think that you can get anything equally sharp if you have the proper abrasives. What I am trying to say is that in my experience(average maybe), fine grained steels hold an fine edge longer. The high carbide volume steels quickly lose that fine edge but will hold a "working edge" longer. Still, as I have also experienced, any steel will lose a hair whittling edge with just a few cuts on cardboard. It probably is a YMMV thing.
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This is somewhat well studied phenomenon in cutlery steels, though it remains a fairly controversial area. All I will say on the topic is that you and Miso may wish to Google the terms "apex stability" and the name "Roman Landes," do some reading, and evaluate for yourselves the extent to which you find the concept of apex stability and its implications useful to you.

On another note: I typically use ~20 degree per side microbevels on my EDC knives at ~4000 grit, and it would be my expectation that such an apex would survive a bit more than "a few cuts" on cardboard before it lost its ability to do crossgrain pushcuts on newsprint. I would also expect that type of microbevel on one of my knives to remain in good enough shape under light use (say cutting up 1-2 corrugated cardboard boxes) to be able to touch up the microbevel back to being able to do crossgrain pushcuts on newsprint with any part of the apex.

Since I rarely tend to use my EDC knives for extended amounts of work in a single day, I can often keep them touched up at near initial sharpness for a couple of weeks between full sharpenings this way.
 
Thanks for your comment, Steel_Drake. I tried to follow the discussion you and others have in another thread on sharpening high VC steels, but it is just too technical to me to understand.....

Anyway, I appreciate that you pointed me to a direction to understand this issue better.

In the mean time, I am waiting for fine diamond stones and polish tapes to see if I can get more stable polished edges on S35VN and S110V. If the apex refinement and stability depend on the carbide volume and size, (and assuming that the carbide at the apex cannot be refined using abrasives without eliminating them) I will not be able to get those edges on the steels. Based on the SEM images ToddS provided in the other thread, carbides at or near the apex appear to be refined during sharpening and stropping.


Miso
 
Procedure updated based on the discussion in this thread and on my recent results. A few more results posted as well.

Miso
 
My current procedure.

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Abrasives used:
#150 diamond stone from Gritomatic
DMT Extra Extra Fine (EEF) stone​
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The point of this method is to create scratch marks with the coarse stone and to keep them as much as possible, while refining the apex with the EEF stone.


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Procedures (The Venev stone should be soaked in water with a drop of dish soap for a couple of minutes before use.)
I do not apply pressure to a stone but just rely on the weight of the stone and the Edge Pro arm.
I only use edge-leading strokes on both stones.

1. Bevel setting
Raise burr with the #150 stone (typically 5~10 strokes on each side unless you reprofile the edge bevel), then deburr with alternate strokes on the stone. The burr should be easy to detect.
(Care should be taken for the tip. You should stop when the stone just goes over the tip. Do not slide the stone beyond the tip. It would round the tip. You can use a microscope to check if the stone grinds the very tip.)

2. Deburring and refinement
Swipe the blade on the EEF stone with a slightly raised angle. Couple of strokes on each side.

3. Wire-edge removal (optional)
Draw the edge on hard wood twice and then on thumb nail with a light pressure to remove any remaining wire edge.
Strop on linen (jeans).
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This is it.
You should get a very aggressive toothy-fine edge.
You can also revive it many times by just using the EEF stone.
This could also work with finer stones like #400 instead of #150.
Loaded strops may further refine the edge (I have not tested this).​
 
How much do you ‘slightly’ raise the angle for the eef stone? Maybe 1/2 a degree or so? Are you putting on a micro bevel? I use the EP, I like the sounds of sharpening like this. Thanks.
 
I do not know for sure, but maybe a couple of degrees.
It does put a micro bevel, which is not obvious even under microscope.
You can raise the angle until you feel edge refinement (the effect is obvious).

Edit: I don't know if raising the angle is important. I just raise it to make sure the stone hits the apex because I am bad at freehand sharpening.
 
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Wowbagger said:
It gets worse than that . . . even the stone flatting equipment is not always flat.
I have a Starrett granite surface plate so I can check stuff for REAL flatness.

The stone leveling stone in this photo, the pink stone with the wide diagonal slots cut in it, was quite far out of flat.


I was able to FLATTEN IT using the diamond plate shown here being verified on the surface plate. (actually I am measuring the depth of the dimples for an on line member. He was saying the dimples had no depth and were flush with the diamonds. Nope, nope, nope they are well bellow the diamonds.



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Flattening water stones with that plate can damage it and wear it out... And DMT won't cover it under warranty if such is the case. They actually make a specific diamond's plate for lapping (dia-flat)
 
This is the edge I got.
The very thin horizontal line at the edge is the micro-bevel created by DMT EEF.
I forgot to put a scale, but the width of the entire edge bevel is about 0.5 mm on this blade.
When I measured the micro-bevel width before on another blade, it was 10~30 micron.

Edge2020.jpg


I am not sure is the occasional deep scratches shown are due to grit inconsistencies of the Venev stone or not.
I recently got an Edge Pro matrix stone and will test it at some point.
 
Edge performance.
Paper cutting test with tissue paper instead of printer or phonebook paper.

 
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