Recommendation? Sharpening advice re asymetric bevel/ edge pro

B

Buttersongguy

Joined
Sep 30, 2018
Messages
85
Hi all,

I’ve searched extensively as I’m sure this question must have come up before but I can’t find exactly what I’m looking for.

I’m sharpening a 110 PM2 for the first time on an edge pro apex (not my first time as I have some other PM2’s but this one has not been sharpened since new) and using a sharpie for checking the angles. I’m finding that on one side when all the sharpie is wiped off I turn it over and it only clears a tiny amount of sharpie near the edge.

I double checked the angles with a digital angle finder and I’m pretty sure that both sides the stone is hitting the edge at within 0.5 degrees of each other so pretty consistent at approx 16.5 degrees.

I have checked by eye and by loupe the primary bevels and centering of the edge and honestly cannot see anything that looks very different from one side to the other in terms of size of bevel. Centering if the edge in the blade stock I just cannot tell.

So the effect of sharpening very lightly with 1000 stone has been to produce a very keen edge which is a secondary bevel from one side and (an almost) primary bevel from the other.

My question is over the course of time which side should I be sharpening more to even whatever it is I can’t see out to make the edge more symmetrical?

I just can’t get my head around it because the two primary bevels look the same width to me and so I feel if I ground down the higher angle side (the one with most sharpie removed) I will end up with a very wide bevel on that side and it will look uneven. If I grind away on the other side that doesn’t feel right either because it’s already at a much shallower angle than the other side as denoted by most of the sharpie staying on. If there is a hard and fast tip for this situation please let me know!
 
Most likely the primary grinds are uneven.

You can choose make the edge bevels even looking by sharpen them at different angles or by grinding the narrower side more each time.
I grind the narrower side down to get even bevels over time.
This would make the edge off center, but you would not notice it.

Bevel.JPG
 
miso2 said:
Most likely the primary grinds are uneven.

You can choose make the edge bevels even looking by sharpen them at different angles or by grinding the narrower side more each time.
I grind the narrower side down to get even bevels over time.
This would make the edge off center, but you would not notice it.

Bevel.JPG
Click to expand...
Thank you very much for taking the time to sketch this I really appreciate it! So if I understand correctly the narrow side will be the one where I am wiping all the sharpie off at the moment (the bigger angle side - green in your diagram)? Is it possible that my edge is not centred from the factory as the bevels currently look similar? So then over grinding that narrow side would increase the bevel on the narrow side to be wider than the other side but push the edge into the centre? Or would you suggest grinding the other side (purple) instead, if indeed I had even bevels but off centre edge to begin with?

Sorry I’m writing this in a confusing way so would you agree with the following rules:

1) If factory bevels are uneven width / same angles but edge is centred to the blade stock then grind narrow green side - results in even bevels but off centre edge. Most material is removed from the shoulder where the primary bevel on the narrow side meets the rest of the blade stock.

2) If factory bevels are even width /uneven angles resulting in edge being off centre then grind purple side (the side where only a tiny bit of sharpie comes off near the edge) - will result in even bevel widths and edge will be centred BUT a lot of edge will have to be removed.

How can one even tell if the edge is centred to the blade stock? My bevels look more or less the same width but one side must have a much steeper angle than the other, so maybe number 2) above is more my case?
 
I think you are overthinking.

These are the two possibilities (the mix as the third), and I don't think you can distinguish them.

Untitled-1.jpg

If you want to keep the factory edge bevels, you can use the different angles to sharpen it (16.5 on one side and a shallower angle on the other).

If you want to sharpen it at the same angle, just sharpen the side with the shallower angle more at each sharpening session.
Eventually, you will have somewhat even bevels at the same angle.

I would not try to make the bevels even immediately nor care about the centering of the edge.
 
Thanks, I think that’s clear to me now. So to sharpen both sides at same angle I sharpen the shallow angle side (the one where only the sharpie close to the edge is removed) a little more every time. In your diagrams above that is the left side of the second and third diagram. This will eventually even out the bevel angles regardless of the actual cause of the original imbalance. The actual edge may not be centred but it does not matter / is difficult to detect from a functional and aesthetic perspective. The bevels will be the same width however at the end of the process over a number of sharpenings.

Please shout if I have still not got it right lol!
 
Would you say my post above is factually correct now? Ie I sharpen the left side of your diagrams that apply to my case. The side with the sharpie only being taken off the edge side of the bevel rather than the whole bevel?
 
Yes.
If you are fine with the angle, you can just sharpen the shallower side (left in the diagram) away more than the other side each time.
That is what I do on my knives.
 
Miso , you’ve been a great help, not to mention very patient while I get my head around this. Thank you so much!
 
I cant draw any fancy pictures but a little simple advice is to walk away when you start getting wound up.
It is easy to remove a lot of needless metal and end up worse off than you were.
Keep it fun, I am willing to bet you have other knives you can use, come back rested and having thought it out.
When I was starting out guys on here saved me a lot of zdp189 and d2 dust on my work bench.
You are in a good place, Miso knows his stuff, we all have the same affliction here... Enjoy!
 
mycough said:
I cant draw any fancy pictures but a little simple advice is to walk away when you start getting wound up.
It is easy to remove a lot of needless metal and end up worse off than you were.
Keep it fun, I am willing to bet you have other knives you can use, come back rested and having thought it out.
When I was starting out guys on here saved me a lot of zdp189 and d2 dust on my work bench.
You are in a good place, Miso knows his stuff, we all have the same affliction here... Enjoy!
Click to expand...
Oh yes! That is sage advice which I unfortunately learnt the hard way. When I first got the edge pro a few months ago I thought my first project would be to take an old s30v PM2 (which was probably around 17 + 17 factory primary and 20+20 secondary off a sharp maker) and give myself an hour before dinner to get the whole thing to 15 + 15. I think it took about a month in the end. Those first hours were some of the most irritating I’ve ever had but gave me a healthy appreciation for blade steel and the benefits of not short cutting the sharpie method. Before this experience it would have driven me nuts to know my brand new s110v was not perfectly centered and would have tried to correct it immediately. Now I just feel it has character that needs a little extra nurturing and TLC every time I go to sharpen it lol.
 
Or you could just relax and enjoy your knife once you get it sharp.
Maybe this will help :
Some Japanese knives are ground just like your asymmetric edge.
Go here to this Link >>>>>
and page down to Figure 6 with the caption
Cross-section of the tip of a typical factory sharpened traditional Asian knife edge, magnified 50x (right-handed)
Click to expand...
:thumbsup:

PS:
You can choose make the edge bevels even looking by sharpen them at different angles
Click to expand...
Sweet !
Thanks!
Now I have a reason to buy the Edge Pro Pro and use it along side my Edge Pro Apex at the same time on the same knife.
. . .
hmmmmmm
or . . . dare I say it . . . a Wicked Edge and clamp the blade off center . . .
PS Edit : set one rod at a different angle than the other.
hmmmmmm
 
Last edited:
Thanks for the link that was interesting. It does seem I have bagged the Sushi chef edition PM2 at no extra cost. I was also worried about sharpening S110v having heard it was difficult but this was the easiest and fastest knife I’ve ever had to get scary sharp so maybe there is something to these asymmetric or one sided Japanese style bevels!
 
Buttersongguy said:
I have bagged the Sushi chef edition PM2 at no extra cost.
Click to expand...
:) :rolleyes:
Buttersongguy said:
sharpening S110v having heard it was difficult but this was the easiest and fastest knife I’ve ever had to get scary sharp
Click to expand...
I went back and looked at your original post. I didn't see where you said you were using diamond stones.
I fooled myself with my Shapton Glass stones that I was getting great edges on my S110V.
I wasn't getting durable edges just weak hair whittling ones that broke down when cutting more challenging media than hair.

With other stones it is readily possible to get very sharp edges but one is just manipulating the steel matrix around the Vanadium carbides like Play Dough with rocks in it (it's possible to hide the rocks in the Dough).

To get durable edges (sharpened Vanadium carbides) I strongly recommend diamond plates; at least for the last stone or two.
 
Wowbagger Wowbagger I am in no way an accomplished sharpener. I got the edge pro a few months back and have been on a learning curve. I’m now at the stage where I am “happy” because I am more easily getting a consistent edge from Choil to tip which I struggled with at first (especially near the choil on a PM2). I bought some of the 0.5 inch edge pro stones and I found they helped a bit with this consistency vs the 1.0 inch which seemed to over sharpen the belly more than anything else, for me at least. With the S110V I thought I was going to have a relatively tough time but all I did was use the 0.5 inch 1000 grit (the yellow one) for a few light passes (it wasn’t terribly dull to begin with) and I was pleasantly surprised at how the edge came straight back really well to the same or better than original factory edge, despite me thinking oh dear about the asymmetry isssue and seeking advice about that. I have a 1 inch 3000 grit edge pro stone which I then also tried but couldn’t detect any real difference to using just the 1000 grit but my testing is basically only as sophisticated as how it feels shaving a few hairs off my arm....

In terms of the edge durability I have no reference point to be able to say it’s a durable edge or not but given my lack of experience I would say I’m sure there is a lot of room for improvement so I’m interested to hear what the best set up (eg best stones) is for the edge pro.

One of the things I like about the edge pro stones is they are mostly the same depth so I don’t have to mess around with a collar too much but haven’t researched other stones. Please do let me know the ultimate setup if there is one!
 
One thing I forgot to mention is the positioning of blade.
Sometimes FFG blades are not really flat and rather convex slightly.
This could make the sharpening angle steeper, if the blade is pushed down too hard on the Edge Pro stage.
 
miso2 said:
One thing I forgot to mention is the positioning of blade.
Sometimes FFG blades are not really flat and rather convex slightly.
This could make the sharpening angle steeper, if the blade is pushed down too hard on the Edge Pro stage.
Click to expand...
I tend to put the PM2 handle right up to the side of the stage so the reference surface is the bit of blade stock that isn’t ground (before the edge starts) which I assume is flat?
 
In that case, it should be fine as long as you don't apply pressure any more than the weight of the stone/handle.
 
You must log in or register to reply here.
Back
Top