Freehand sharpening question

btron · #1

Hi guys, just put an edge on my XHP Native. It isn't perfect but it's only my second edge that I've put on a knife. Used Shapton Glass 500, 1k, 4k, 8k and KP strop. It looks good enough for me although around the ricasso you can see some dissimilarities.

My question is...what am I doing wrong? It won't cut through phone book paper smoothly at an angle, but will cut it decent when the blade is straight. It seems to get caught when slicing, but with a back and forth motion it is fine. It will cut hairs off my arm as well. When I feel the edge with my finger, it is nice and smooth and feels sharp when I apply little pressure. It just doesn't seem to cut paper as well it appears to be. Does the polished edge make it not cut through paper as easy as a factory edge? Now I know, I'm not gonna be cutting phone book paper, but I'd like to know that it would be able to :p

The angle of the edge, I don't know. I tried to keep it as close to factory as I could trying to make it a tad thinner. Just kinda went with it and kept a consistent angle through the stones.

78lilred · #2

You could have some burr or a wire edge, possibly rounded apex. Should cut just fine at 500grit, progressing after that is just refining the "teeth".

Cliff Stamp · #3

You are jumping grits and the apex isn't getting ground.

"It seems to get caught when slicing"

If properly finished, the blade will do that off of the 1k Shapton, likely even the 500.

There is one of two things happening :

-the blade is never apexed
-it is apexed and a burr is formed which isn't removed

btron · #4

Thanks guys. I'm guessing I never established the apex since I can't see or feel a burr. Any tips on creating that apex? I'm afraid to remove too much metal I notice when I sharpen.

Cliff Stamp · #5

Get some cheap knives to practice on, you have to be fearless when sharpening, if you are hesitant and doubting yourself it isn't going to happen.

-cut the edge off so it reflects light
-grind alternating on both sides until the light stops reflecting, check frequently

When the edge stops reflecting light, depending on your vision, it will be ~20 microns thick, this means it is right at the point of being apexed. Of course if you are grinding with a coarse abrasive then it will be apexed once it stops reflecting light as the coarse abrasive has greater than 10 microns deep scratches.

But the main issue is that you can't be timid, you won't develop the necessary motor skills / feedback control if you are, so forget about that. Tell your friends you will sharpen all of their knives for free, you will quickly get past being nervous to any extent.

btron · #6

Thanks for all the help Cliff! I really appreciate it! I'll be sure to get over that nervousness. I have an Opinel that seriously doesn't even have an edge. I'll probably practice on that.

Are there any videos on making the apex? I tried looking but only found videos on the Edge Pro Apex :P

Cliff Stamp · #7

This is doing it on a brick : https://youtu.be/mSt2mCWGFII . It is easier if you use an actual stone, same basic process.

btron · #8

That is just amazing that you were able to do that on a clay brick :o

Not sure what I'm doing, but I did what your video showed and it just made the knife incredibly dull

You must have the magic touch Cliff lol. Might as well stick to the Sharpmaker :p

Cliff Stamp · #9

There are a number of things which can go wrong, you can't go as fast as I went in that video until you can feel the edge on the stone and know when you are above the apex. If you actually hit the apex going that fast then depending on the stone then you can damage the edge, similar if it rakes over the corners or over the end.

This is why I really recommend getting a cheap knife you don't mind using up and just grinding on it until you know how it feels. It is pretty easy to learn because you just put the knife at a really high angle (like 45) and learn how that feels and then put it at 5 dps and learn how that feels. This is how it feels when it is at the apex and when you are below it.

Then you can start to tell when you are approaching the apex and you slow down and finish the edge with a micro-bevel and then minimize the burr as necessary.

As well set a goal for sharpening, however long it takes you now, cut that in half and don't spend any more time than that, and set as your goal twice as sharp as you can get it now. Don't get frustrated if you can't do it right away, just make sure your goal is always well ahead of where you are now.

My current time limit is one minute and the goal is push cutting newsprint, cross grain, true-90. I don't get there all the time, and if you had asked me even last year if that was possible I would have thought no. But if you keep moving your goal it has no where to go but up.

btron · #10

Thanks Cliff. Your kind words actually make me not give up :p

Welp, I made an edge on my Opinel no. 6 that before, was completely nonexistent. I got it to be able to slice newspaper and phone book paper relatively easily only using the 500 glass stone. It can also take hairs off my arm at the right angle. I did pretty much the same technique as I've been doing. Any particular reason why I was able to get my Opinel this sharp, but not my Native? Is XHP really that hard to get a nice edge on? It took me maybe 15 minutes total for the Opinel and it is a joy to cut with.

With that being said, if I was able to essentially create an edge that is able to cut phone book paper from an "edge" that was nonexistent, then my technique can't be that bad, can it?

Also, to be sure, 1k grit will refine the edge more and make it sharper correct? Whereas 4k and 8k are more for polishing, not necessarily making it sharper?

78lilred · #11

Opinel and other carbon steels will grind relatively easy compared to the high carbide steels like s30v/xhp/etc. Congrats on getting it figured out so quickly and glad Cliff came in to help. The grit to stop at will depend on the job of the knife. Kitchen knives will like the 4k/8k finish(depending) while most pocket knives and high carbide steels will hold a working edge for a decent amount of time with a 220-1k finish.

btron · #12

Thanks man. I'm hoping I figured it out haha. I still want to mess with the edge on this Opinel to get my technique fully down. I kinda want to mess around and try to get a convex edge on this thing using the glass stones.

jackknifeh · #13

There is nothing magical about a "factory" edge. In fact a lot of people are of the opinion the factory edge will not perform as well as an edge that has been reprofiled and sharpened because of reasons we can discuss later. Also, the factory edge is at a higher angle than what the steels can hold an edge with most of the time IMO.

Lots of guys here have great advice. Cliff's opinions and advice is usually accurate I've found. I have to say I have learned a lot from his posts in the past 6-12 months.

I've learned so much from the guys here it's amazing. Also, from people on other forums, emails and on the phone. All of this has resulted in the technique I use now. It is simpler and easier to learn than anything I've done in the past. Also, and possibly more important is I know why I do everything I do. My motions are not what has developed over time based on little or no advice or teaching. In as effort to pay back for all the help I've received her and other places I made videos of what I'm doing now. I posted them yesterday in this thread: http://www.spyderco.com/forums/showthre ... -technique. This is a simple, easy to learn technique that works. I also know why I do everything I do. Check it out if you want. By posting these videos I hope to accomplish two things. The first is to help otheres. Especially the guys just getting started. The other thing is I'd like to get opinions on what I'm doing now (good or bad). I'm still learning.

Glad you are making progress with your edge. The thing about the portion of the edge at the handle being inconsistant. I believe this is normally caused because when the stone is at that portion of the blade the steel RIGHT AT THE START OF THE CHOIL is not straight. I normally create what is known as a "sharpening notch" there. By doing this the edge remains straight and doesn't cause the edge to "raise" off the side of the stone at the corner edge of the stone. This has been discussed in detail here and all info can be found. Or ask in this thread if you don't understand the "sharpening notch". searching on the forum isn't the best.

Good luck.
Jack

Fancier · #14

Btron, every Opinel I've owned has been ground very thin. I've never had to remove very much metal to achieve sharpness on an Opinel.

Cliff Stamp · #15

btron wrote:I did pretty much the same technique as I've been doing. Any particular reason why I was able to get my Opinel this sharp, but not my Native?

Yes, you didn't think it would not be a problem and so it wasn't.

There are slight differences due to the fact the Native is harder to grind and the angle is higher, but these are minor influences. The main one is that you simply don't care what happens to the Opinel and so you are relaxed.