Sharpening questions.

J

Justin Wood

Joined
Apr 2, 2021
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15
Ok so I started very recently getting into knives again. I randomly heard the term “super steel”… I went and checked my knife collection from when I was a kid and realized all I had was junk designated only as stainless. (Most of which I probably picked up from gas stations or flea markets in the 90s)

So I bought some knives… I have 154cm, d2, s35vn, 14c28n, 7cr, AUS8, 1095, 1084. At first when one got dull I was sharpening on a smilths 4 inch diamond stone (the one from Walmart). I was getting a paper sharp edge that would not shave. So I made a strop. Then I was able to shave a few hairs here and there, but my edge was not consistent. I would have dull spots that mostly resided on the base and tip of the knife.

So I bought a worksharp precision system. Now I can get my blades sticky sharp. They will shave with ease (my arms are bald 😂) However the one thing I am not getting is this mythical thing called a burr… I have been paying attention, but I have never seen or felt it. Sometimes I notice a small dark grey build up on the edge of the knife… I would equate that to saw dust but it’s steel. I don’t think that is a burr..? What am I missing? I know it must exist… I feel like I am getting the desired result, but confused/wondering if I could be getting better/faster edges.
 
How did you check for the burr? How good is your eyesight? As far as I am concerned, if you have sharpened your edge to an apex from heel to tip, then you had to have raised a burr during sharpening.
 
Eye sight is decent, but I can tell it’s starting to go lol. I have looked for it by sight, and I tried to feel for it with my finger nail going from top of the bevel to the edge. I have also tried with the pad of my finger. The problem with “feeling” for it is that I do not know what it feels like.

I honestly wonder it it’s something with my technique. Like I am knocking it off… because of my sharpening motion. With the precision sharpener I am doing an up and down motion across the edge starting at the edge and pushing towards the shoulder of the bevel.
 
some of the steels especially the harder super steels won't raise a burr as noticable as others. diamond also will reduce the burr along with the worksharp. try only sharpening one side and see if you can get a burr
 
Maybe you’re not staying long enough on one side to form a burr.
If I switch sides often when sharpening, I will barely feel the burr. But the blade gets sharp, you’d be surprised what a couple of passes will do when you get the edge shaped up and even.
 
imo if you're getting sticky sharpness you should keep doing what you're doing and not worry about the burr that you are most likely creating.

it's probably just too small to detect. like others said you may want to stay on one side until you FOR SURE feel one start up.

those precision systems are nice.
 
J Justin Wood , if your knife can cut tomato skin at 90° to the surface, by the weight of the blade/knife, then the apex is burr-free and you don't need to worry:

It can shave, but not slice a tomato????

I’ve been using Chosera and Shapton glass stones on a variety of knives and I loose the ability to slice a tomato at some point each and every time. 3000 on the Chosera is my last good slice (I can and have gone to 10,000 with the hair leaping off my arm). And 2000 on the the Shapton as well ( I...
bladeforums.com bladeforums.com

If you want to finally see and feel what a burr is:

How To - Detect or Remove the Micro Burr?

I enjoy freehand sharpening and even developed my own technique which i call 204-freehanding. In the past 2yrs i successfully freehanded hundreds(!) of various edges (EDC knives, kitchen knives/machines/cutlery, gardening tools, other cutting tools, etc.) to scary sharpness and in all modesty ;)...
bladeforums.com bladeforums.com

Good luck, i'm out.
 
The 'dark grey build up on the edge' is usually a strong indication there is a burr, at least in some portions of the edge. That buildup is the stuff that collects behind the leaning burr, as dirt would collect underneath the fingernails, if they were scraped along a dirty surface.

And the issues with variable degrees of sharpness, i.e., cutting paper but not shaving, and the 'sticky sharp' description of the edge would (maybe) point to a combination of likely burring and other portions that probably aren't fully or cleanly apexed. Some 'sticky' edges feel as such due to heavy, toothy burrs. But depending on what's meant by 'sticky' in one's own description, it can be a good thing too.

Rounding the apex would prevent a consistent burr from forming or holding at all. Steels like the mentioned AUS8, 154CM and 7Cr are usually prone to forming and holding pretty tenacious, stiff burrs. So with those, it should be more obvious. If it's not seen with those, then the edges are likely not fully apexed and/or they're rounded over.

On guided systems, the burr created might not reveal itself in such an obvious manner, because the unchanging angle of sharpening tends to prevent the burr from folding over in a more obvious way. The 'burr' formed can get ridiculously broad, but very, very thin in cross-section. So it produces an edge that's much too weak for anything other than shaving. So, to check for it's presence, something more than shaving needs to be tested. Cut some paper, then draw the edge through some hardwood (across the grain), and then test paper-cutting again. If there's an aligned burr on the edge, it won't survive that treatment - it'll either break away or fold, after which the cutting performance will likely change immediately and obviously.
 
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Justin Wood said:
Eye sight is decent, but I can tell it’s starting to go lol. I have looked for it by sight, and I tried to feel for it with my finger nail going from top of the bevel to the edge. I have also tried with the pad of my finger. The problem with “feeling” for it is that I do not know what it feels like.

I honestly wonder it it’s something with my technique. Like I am knocking it off… because of my sharpening motion. With the precision sharpener I am doing an up and down motion across the edge starting at the edge and pushing towards the shoulder of the bevel.
Click to expand...

I use a piece of paper towel bent in half or a Q-tip to feel for the burr. Not the regular Q-tips, but Q-tips that have the cotton packed tighter on the stick. I bought them on ebay for cleaning electronics, but they work great checking for burrs also.
 
Thanks guys for the great tips and the explanations. I think I will have to try some of the suggestions here.
 
Justin Wood said:
Thanks guys for the great tips and the explanations. I think I will have to try some of the suggestions here.
Click to expand...
Another suggestion, get yourself a hand held LED microscope, you can see what is happening to the edge, and if there is any sort of burr or wire edge, you can see it. I have found these invaluable in sharpening and you will learn so much about edge geometry, you can get them on the net for about $20, well worth it. :thumbsup:
 
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