Sharpening problem

F

Frajbos11

Joined
Dec 5, 2013
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5
Hi. I use Sharpmaker to maintain my knifes. But today a found a problem when sharpening my Resilience. I was sharpening it as any other day and then the knife wasnt sharper... So I marked the blade with blue marker to find out what is going on. The stone isnt hitting where its supposed to be. I use 40 inclusive... I was sharpening this knife yesterday (use it a lot) and everything was OK :mad: It was like impossible to take a photo of it with my phone :) Any idea what how to fix this problem?
Thank you very much...

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That just means that the factory edge is more acute than 40 degrees. Have you tried the 30 degree setting?
 
I guess I can't see your picture very well, it looked to me like the 40 was hitting the microbevel, but not the main bevel. If you're not hitting all the way out to the apex with 40 inclusive, just keep working it until you do.
 
Frajbos11 said:
Indeed I tried and the result was almost the same (not hitting the microbevel) :(
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I am not sure if I understand. I guess you mean that little bit of leftover red appearing color near the apex? If so, it may be technique (are you rotating the knife to follow the bevel or are you "inwarding" the handle to do the same?) or a problem in grind at that very spot. Did you make sure you got a burr on both sides in that area while grinding/sharpening?
 
After opening the image in a new tab in my browser, and zooming WAAAYYY in to magnify, I think I can see what you're talking about. Just a hair-thin stripe of ink along the very edge? If so, that's just an indication that your edge is a little more wide than the SM's angle settings (I'm assuming wider than 40° inclusive). Looks like you're very close to being there, though. I'd just keep going at the 40° setting until it's fully apexed. Ideally, for the long run, I'd prefer to grind it down to fit the 30° setting, after which the sharpening and maintenance on the SM will be much, much easier. It'll obviously take some work to get it there in the first place, though. Diamond rods for the SM might be worth considering.


David
 
The first thing I do with all my knives is "index" them for the Sharpmaker. I free hand them down to about 25 or 27.5 inclusive and then I have my choice of 30 or 40 for a microbevel. Makes touching up a snap and the freehanding delivers a mildly convexed secondary bevel which is nice for a number of reasons. I am having most excellent luck with my Sharpmaker diamond rods. They are much coarser and cut much faster than I was lead to believe...and I'm glad of it. You can do a pretty fair job of reprofiling if you don't have too far to go. It still takes a lot of strokes but your arm will wear out before you get anywhere with the standard brown coarse ceramic.

I just did a D2 blade. Started with diamond plates free hand. I went ahead and put a 40 degree micro bevel on it and I wasn't happy with the performance...it's a big thick Adamas 275. So I took off the 40 micro with the diamonds at 30. I didn't get the whole thing last night. I need a few hundred more strokes on the diamonds and I'll have it. Compare that to even S30V. I removed a 40 micro with those in about 60 strokes per side...probably fewer. D2 is tough!

Your Resilience is made of good steel but it isn't going to be near as hard to sharpen as D2. David is absolutely correct. You almost have that. I'll bet 100 or so good clean strokes pers side (may 200) and you'll have it.
 
Yes, thats probably it, the microbevel is more than 40 degrees inclusive. I just cannot figure out how that happened... I have this knife for pretty long time and there really was 40 inclusive .. ;).. Another problem could be, that the main bevel is not very symmetrical, look what happens if I change to 15 degrees per side.. I guess this also explains why the second bevel (smaller edge=microbevel?) is on one side of the blade bigger?

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Asymmetrical blade grinds are very common, and more noticeable near the tip, as the steel becomes thicker behind the edge. Relative to the centerline (line drawn from spine's center to the apex of the edge), the steel on one side will almost always be thicker on one side, relative to the other. At least a little bit of variation in most any knife, and some are much worse.

It's possible the microbevel >40° came about from one or two erroneous sharpening passes on the SM, if the blade was inadvertently tilted slightly off of vertical, away from the rod. This is very easy to do (I've done it many times), and it only takes a pass or two to do it. For me anyway, it's much more likely to happen the more fatigued I become. Easy to lose focus for a second, if getting tired... :o

At any rate, it still looks like you're very close to a crisp apex. So, I'd just keep going until it's there (or take a restful break first, then attack it again when you're feeling fresh; that's what I'd do :) ).


David
 
And should not I maintain the bevel also to make the microbevel smaller? On one side the microbevel is like 3/4 of the bevel (photo in the first post):(
 
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As above, non-centered blade are very common, that is the reason why high quality custom knife makers put such a big deal into having the blade/grind centered!

And yes, at least in theory (but also in reality if you use your knife often enough and therefore sharpen it often enough) you should maintain all bevels regularly, meaning the main grind (flat, convex, etc.) to keep the cutting ability up to par, the secondary grind/bevel and, if present, the tertiary bevel (regular bevel, microbevel etc.). Most knives are overbuild, the blade thickness before the initial sharpening is often too thick, making the end user sharpening much more difficult than needed. Really, on a well made knife, the edge bevel should only be a fine line, easy to sharpen and maintain. That is the reason why I now prefer zero convex grinds (not meaning convex edges!).
 
Ok.... I will today sharpen this knife, but I you were me and you had this knife in the photo, would do something about this bevel? Or should I just wait till by sharpening the bevel dissappears and then completely resharpen it lets say 30degress inslucive and then put a microbevel on it?
 
Frajbos11 said:
Ok.... I will today sharpen this knife, but I you were me and you had this knife in the photo, would do something about this bevel? Or should I just wait till by sharpening the bevel dissappears and then completely resharpen it lets say 30degress inslucive and then put a microbevel on it?
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I wouldn't worry about the asymmetry of the bevel at all; therefore I see no need to completely re-bevel just for this. From the picture, it doesn't look as bad as many others I've seen. As you've suggested, maybe waiting until it's convenient to re-bevel to 30° inclusive is the ticket. If you finish it by fully apexing it now, at 40° inclusive, the knife will be just fine for a while. When it's in need of another major re-sharpening, then maybe that's the time to thin it out.


David
 
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