Sharpmaker observation

T

trugracie

Joined
Nov 10, 2009
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Well after a long wait I finally received my Spyderco sharpmaker. I immediatelly took it to my Griptilian which takes an awesome edge on it with my belt sander set up. I wont say it was really dull, but was more of a touch up that it needed.
As expected it took a ridiculous sharp edge using the sharpmaker and the ultra fine stones. Quite frankly My griptilian had never been this sharp ever, the only problem is, the edge retention was very weak with this method.
Just to be sure, I took my other knives and put that same ridiculous edge on with the sharpmaker and took them to work one at a time. Sure enough, all of them lost their edge after some cardboard cutting in one day. Me being curious I went back to my belt sander and sharpened all my knives with the usual 800 grit and then leather with green and white compound. To this day, I've used my griptilian for 4 days now and it still shaves hair off my arm.
Do you guys have any clue as to why the v edge created by the sharpmaker dulls so easy, or is it the simple fact that the convex edge made by my belt sander is much more superior?
 
Look up the term "wire edge." You'll have to adjust your sharpening technique, I think.
 
Please post sharpening discussions in this forum, Maintenance, Tinkering & Embellishment.

Tsujigiri nailed it: wire edge. When I use the Sharpmaker, I hold the blade vertically to sharpen, but then I hold it at a parallel angle to the opposite stone and lightly stroke a few times down each stone, and strop it on my shirt sleeve or pants leg to break off that wire edge.
 
I'm also betting it's a wire edge issue. Ceramics are VERY GOOD at creating them, especially if much pressure is used (which is multiplied greatly on the edges/corners of the triangular hones, or on the radius of round ceramic hones).

On the upside, ceramics are also excellent at removing the burr/wire edge, IF you know to expect them. Just elevate the edge angle slightly, and make a few passes (less than 5) on the rods with feather-light pressure. Then strop. Some steels are more prone to creating stubborn burrs & wire edges, so if there's still some burr or wire edge left, repeat the process. LIGHT PRESSURE is key to removing them, above all else. Too heavy will just fold it to the other side, or perhaps even make it bigger. Light pressure will work to gently 'file' it away, or break it off.
 
When you say "lost their edge", just how dull were they after one day? Do you have a jeweler's loupe or magnifying glass?

HH
 
Wouldn't cutting through cardboard be one of the classic ways to remove a burr?
 
So that's it!!! I love this sub-forum. Same problem for me...also new with a sharpmaker.

I still prefer to freehand with diamond plates but the ease and simplicity of the Sharpmaker just seems too practical to pass up for touch up jobs.
 
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"Anybody with eyes and a fingernail can identify a wire edge, right?"

You would think so, but we are also dealing with people new enough to sharpening that some of them don't know what a wire edge is. That's why we have to start with the basics.
 
With regard to removing burrs or wire edges, some are easier than others. Cutting cardboard might take care of some (with some steels), but not all. I used to 'handle' most burrs by cutting into a piece of hardwood (cross-grain). That took care of some of the easier ones. The reason I started relying on ceramic to remove them, is I eventually realized it was my 'go to' means for burr removal, if/when the wood/cardboard/etc didn't quite get it done. Oddly enough, some relatively 'soft' (read: easy) steels I've dealt with, like 420HC blades on Case stainless knives, have had some extremely stubborn burrs on them. I've come to always rely on a ceramic hone to clean 'em up. VG-10 and ATS-34 are a couple of others that have sometimes proven stubborn. I deal with them the same way.
 
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@ Obsessed

VG-10 is my steel "in question". So I stropped the living daylights out of my Endura, green compound, very light pressure, very high number of reps. In your opinion, would this knock a wire edge off of a VG-10 blade? I am definitely going to go with your ceramic modified angle method described above next time. I was wondering why I had so much trouble getting it sharp but I finally did after probably several hundred reps on the strop. I mean I sat there and watched TV and stropped until my wife said it was "just creepy". I too am a little obsessed with edges but I am not nearly so experienced with them.

Anyway, please comment if you care to. I will be trying your method of removing the burr the very next time I use the Sharpmaker.

Q
 
When I know I've got it right on my Sharpmaker and it's still snagging a sheet of paper. Happened last night on two knives I touched up - I drag the edge through a large cork and then hit it a couple more strokes. Did this and the blades hissed right through the paper cut test. Good bye wire edge! :thumbup:
 
HoosierQ said:
@ Obsessed

VG-10 is my steel "in question". So I stropped the living daylights out of my Endura, green compound, very light pressure, very high number of reps. In your opinion, would this knock a wire edge off of a VG-10 blade?
Click to expand...

That's exactly why I remember VG-10 to be troublesome. The first time I re-bevelled one of my VG-10 knives (and finished with a ceramic hone on my Lansky setup), I kept noticing it scraping little bits of leather & compound from my strop (from the underside of the edge; a wire edge was doing it). So, I kept stropping, on the assumption I'd eventually get rid of the wire. No such luck. That's when I decided to take other means: cutting wood, then finally ending up up using my Spyderco ceramic hone.

I am definitely going to go with your ceramic modified angle method described above next time. I was wondering why I had so much trouble getting it sharp but I finally did after probably several hundred reps on the strop. I mean I sat there and watched TV and stropped until my wife said it was "just creepy". I too am a little obsessed with edges but I am not nearly so experienced with them.

Anyway, please comment if you care to. I will be trying your method of removing the burr the very next time I use the Sharpmaker.

Q
Click to expand...

Just remember to keep it light on the pressure, when using the ceramic to remove any burr or wire. Test your edge after every 2 or 3 passes, on a piece of paper (draw/slice cut, from the ricasso all the way to the tip). When you can slice cleanly & repeatedly like this, through the paper, along the full length of the edge, you should be in good shape. That's when it's time to take it to the strop.
 
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This is from Jeff Clark. After I read it my sharpening results improved 100 percent . With the Sharpmaker this would be easy.


"Burrs form when you remove more than the minimum amount of material to reach an edge. The burr is the remnant of the material that you thought you removed from the apex of your edge, but in reality it folded away from your hone as you worked. Even with a light touch you can get some burr, but using excessive honing pressure (particularly on a narrow honing surface like a ceramic rod) will cause a larger fraction of the edge to bend out of alignment. So first of all use light pressure as you approach the end of your honing process. Another thing that maximizes a burr is honing on one side at a time. As you get to the later phases of your honing be sure that you are honing on alternate sides of the edge on every stroke (left-side, right-side, left-side, right-side...).

A burr forms because your hone's abrasive particles are not shaving off little bits of the edge like a razor blade. The particles varie from rounded, to pointy, to flat-topped. They shave off some material, but they also have a tendency to simply plow through and bend over some of the blade material. If the blade is extremely brittle like glass it will microchip as you hone it. If the blade material is softer it will not chip, but it will tend to do some burr formation as soon as your edge gets thin. If your carbon steel knife is 58 or 60 RC hardness it will form a bit less burr than a stainless steel blade that is 56 or 58 RC. If your stainless steel has large chromium carbide grains in it those will tend to fold over rather than get cut.

The sure way to debur an edge is to lightly hone edge-forwards at an angle that is significantly greater than your normal honing angle using an abrasive that cuts more than simply polishing. When I do most of my honing at 15 degrees I will bebur using clean medium-grit ceramic rods at 25 degrees. It only takes about 8 light strokes to do it (left, right, left, right, left, right, left, right). Then I go back to 15 degrees and restore my edge with a minimum number of strokes. If you go back and hone too much you will just create another burr.

You may actually still have a burr on your carbon steel blades. Carbon steel is easy to push into alignment and it forms a fairly sturdy burr. For years I happily used burred carbon steel blades. They shaved great and I didn't notice that they dulled faster than they should have. For a kitchen knife you might be happy if you just pushed your burrs into alignment by a little light stroking on smooth ceramic rods or on a smooth steel. You could do the same thing if you sort of lightly hone a burred edge on the side of a glass. Remember to work on a soft cutting board in the kitchen."
 
Thanks for all the info gents.
Will work on that burr tonight and hopefully get some nice long lasting edges.
 
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