OK...im frustrated

I've noticed, on virtually every single knife from the mfr (Benchmade, Ontario, Buck, even Bark River [although this one may be subjective to my imagination]), that the edges are never exactly the same. The only ones I'm unsure about are my Spydercos - one is a fully serrated Delica and the other a Police model which I haven't picked up in over a decade....so they may or not be asymmetrical.

If the difference in the asymmetry is minor, I usually compensate by tilting the offending edge by eye until I get tired of it (after a few sharpenings). Then I'll pick an angle, usually about 12.5 deg depending on the blade, and re-grind the edges so they're both the same. If it's major, I've been waiting for the first sharpening, then re-grinding.

I'm beginning to reach the conclusion I could challenge a production knifemaker to make both edges the same, and win! It's human error, I think, even if they're using machines because they still have to "setup" the knife for grinding.
 
I believe I have noticed the wire edge. I had the knife starting to feel sharp last night, not nearly as sharp as ir probly should be, but stil it was at least getting there. I noticed a bright wavy looking line at the edge and it was not along the entire blade, only near the back. I was also starting to feel a burr on one side of the edge or another. As I gently ground the edge, I could hear what sounded like a slight snapping sound (maybe the wire edge breaking?). After swiping the blade at a slightly steeper angle to attempt breaking the burr, the bright line dissappeared. But the knife was still feeling pretty dull. So I am failry cinfident I am able to raise at least an imperfect burr, but removing it and not dulling the knife at the same time has been difficult. So, as many forum members have pointed out very early on in this thread, I may be struggling with a wire edge. It made the edge look ragged and feel very dull so I assumed I simply wasn't forming an edge at all. So, I need to reform the edge as I have probly dulled it trying to remove this burr. Once I regain the burr, do I break it off by softly swiping a higher angle and then do I finish off the edge by making gentle strokes to smooth out the broken part? Even after removing what I at least thought was a burr, the edge still feeled dull.
 
There is something to consider that I don;t think has been mentioned before in this thread. That is: on some knives (maybe all), the primary grind gets more shallow (obtuse) from the belly to the tip. In other words, if the primary grind of the knife is 7 degrees, it's usually consistent at the rear of the blade, from the hilt to the beginning of the belly. That may explain why you're able to get it sharp in that area (coupled with the fact that there's less wrist involvement between hilt and belly). However, from the belly to tip, the primary grind could become more shallow, (say 8, 9, or 10 degrees), therefore dictating a more shallow attack on the Shaprmaker rods (say 17 or 18 degrees as opposed to 15). Does this make sense? Study the spine of the knife - you can;t see it but you can envision it.

Now, it may seem irrelevant if the knife grinder doesn;t follow the primary grind when grinding the edge. I mean, if the edge is ground at say 15 degrees, consistently throughout the length of the blade, then it doesn;t matter if the primary grind is off a few degrees one way or the other. BUT, I can say, at least on my RAT-3, that this is the case. I also notice it on almost all my Bark River convex grinds. I must grind more steeply as I approach the tip as opposed to the shallow angle that will work from hilt to belly.

Does this make sense? The only confusing point might be in the use of the words "shallow" and "steep", each sharpener I suppose has a different interpretation. WHen sharpening, I mean shallow to be the lessening of the angle between blade and stone - some guys might call that steep.

Anyway, consider that when sharpening. I have observed this on my knives and have also experienced, many times over, the rearmost portion of the blade being sharper than the end nearest the tip. It is the geometry of the grind, I'm sure, and we have to compensate for it.
 
I see what you are saying Stretch. My dad just bought a JET slow speed wet sharpener, and I am trying the kabar on it. Let me tell you, for me at least, this thing works infinitely better than the Sharpmaker. I have one side ground at 17deg and am working on the other side. The grind newr the tip becomes very flat looking and large for the reasons you specified (blade being more obtuse in this area). I didn't compensate for this, but just took the grind up to the tip. I had not idea how much metal I still had to take off in order to achieve my target edge. It would have taked forever on the sharpmaker, but most importantly, the edge is nice and flat and clean now, not all rounded and botched up like I made it on the Sharpmaker. I know the Sharpmaker is a good sharpener, just being a noob, the JET is much faster and easier to use and less frustrating. The knife will almost shave hair and I havent even finished the other side of the edge yet. Its sort of acting like a chisel grind right now as one side is complete and other is not. With practice I should be able to sharpen all my knives well. I realize I do need practice though before I ettempt sharpening on an expensive knife. Its still easy to mess up if your not super careful. Anyway, got to get going...Halloween party time. (wife making me go, i'd rather stay home and sharpen)
 
without a distal taper, any knife with a point higher than the edge is going to thicken at the tip, the grind gets shorter as the edge turns up. Depending on the knife/use, sometimes I alter the angle to keep the height of the edge bevel the same along its length, others I grind the same angle all the way down and end up with a nice wide edge bevel at the tip.

Once you get it sharp with the power sharpener, keeping it sharp with the Sharpmaker will be easier. Of course, you'll need to use the 40 degree slots with the 34 degree edge you're applying.
 
sounds great. I look foreward to using the sharpmaker to maintain edges, just not to create them!
 
As long as you have a power sharpener you should sharpen to 10 degrees per side and only microbevel at 15 with the white rods. 17 degrees is still too obtuse for anything other than a blade made of junk steel.
 
10 per side is so flat, I don't even know if all my knives would even take that edge without grinding away 3/4 of the blade thickness.
 
Well, you could start the edge at 12.5. THat's what I do on some. Bear in mind too that the primary grind of 7 degrees isn't consistent with all mfrs. Some like it a little steeper and some more shallow. I haven't ever ground an edge as shallow as 10 degrees, but I've seen other Forumites besides just Jeff saying that, so there's got to be some wisdom behind it.

Maybe try 12.5 with a 15 degree micro-bevel and see how you like it.
 
Maybe you're right - I don;t own a Kabar so I couldn;t say I tried it on one. Well then, 30 with a 40. That's not too thin or sharp for any knife, in my estimation.
 
What is a typical factory edge grind for a quality knife like the Sebenza? I am just curious. Do they have secondary bevels?
 
Sebenzas convex edge. Generally, but not always, they can be sharpened on a Sharpmaker using the 40 degree setting. I have one that was < 40 on the belly but > 40 about the last 1/2" to the tip.

It worked fine for me for quite a while but once I got my Edge Pro I thinned it to 10 degrees per side with a 15 degree per side micro-bevel. It performs much better now.

Spyderco is one of the few manufacturers you can count on having < 40 degree edges. A few years back Buck started making its edges thinner.

What you're going through is not unusual. Many knive come > 40 degrees. That's why an extra course bench stone is an excellent companion for a Sharpmaker.
 
I have a JET slow speed wet sharpener available to me for use and I am thinking of using it to grind primary edges and then use the Sharpmaker to create the microbevel. I would use the JET for both, but I find it difficult to get a finely ground micro using the JET as it takes off a lot of material, and the honing wheel seems to dull the microbevel rather than sharpen it. In otherwords, it seems theres a learning curve to the JET as well as the Sharpmaker. However, It is fairly easy to grind a decent edge with the grinding wheel and polish it up nicely using the honing wheel and then go to the Sharpmaker for a finely honed and polished micro using the full set of rods as well as the ultra fine rods. I am going to try this proceedure on a couple more test knives and see how it turns out. I am pretty much done with the kabar. It is not shaving sharp but nearly there. Its sharp enough for now and besides, i'm sick of looking at the thing. This forum is great. Tons of knowledge and loads of help from everyone. Thanks!
 
SUCCESS!!!!!!!

I am in complete and utter shock. I took out my United Cutlery Rambo 3 knife and decided to have a go at it. I was hoping my results would be better when starting with a fresh knife and VOILA, instant razor blade. I took the knife to the JET grinder and put a primary edge of 30 inclusive and then polished the edge to remove as many grind lines as I could and to make the edge look as shiny as I could get it. I was already fairly impressed with the semi-shaving sharpness of the large 30deg edge. I thought to myself "Why do people even use micro bevels anyway?". I thought the only purpose of a micro would be for ease of sharpening as there is simply less material to remove than to sharpen a large primary. Then I put the Rambo 3 through the entire Sharpmaker process, including ultra fines, and oh my goodness. I was sort of sceptical about how well it would work, but work it did. The knife is by very far the sharpest thing I have ever held in my hand. It shaves with zero effort and although it wont pop hair consistently, it will pop a few here and there when gliding it above the skin. Never had a knife that push cuts, but this one does it pretty consistently through notebook paper (have yet to try newsprint, but something tells me it will work there decently as well). I am totally extatic! I have yet to get better at grinding my primaries as far as both sides being consistent on and around the belly and up to the tip, as manual control of the angle is required here when using the JET. I also need to learn how to lessen the angle of the primary near the belly, as the 30deg really flattened out that area of the knife, and went well into the tip, effectively removing it. I am sickly impressed with the Sharpmaker and its ability to tun a hugeass knife into a razor blade with a handle. Holding a knife this sharp now becomes slightly nerve racking. One little touch of the blade or any carelessness will cause a deep cut. Thanks everyone for your help getting me to this point. I have a ways to go before I am confident in my ability to take a new knife and grind/sharpen it without damaging the tip and belly etc....but I am at least confident that I know how to make it insanely sharp. This is so much fun =)

Edited: I noticed no burr or wire edge. Is this sometimes normal?
 
Congratulations! :D Just don't use the JET on a knife with a fairly thin blade (thin is different from edge angle) like a kitchen knife. You are much better of with sandpaper, since you don't have much material to grind away.

Yes, some steels don't burr very much. Burr is not necessarily a good thing but rather something to be avoided. Only when you start out it is important to use the burr as indication that you finished grinding the primary edge bevel, that you really have come to the very edge. Once you get more experienced, you want to keep the burr as small as possible, since it can be a hassle to get rid of.
 
Esav Benyamin said:
"one large bevel" continues to the very edge getting thinner and thinner which means it is not very durable: it will chip or roll easily. The more obtuse microbevel is very short, does not significantly effect how the blade slips through the material it will cut, but it will also not chip or roll as easily.
Click to expand...

I get it now... Thanks Esav.

I gave my ka-bar to a friend a few years ago to resharpen it, which he did to a razor edge. You could tell by the way the coating was wore off that he had just made one large bevel, tapered all the way down to a very fine edge. While using the knife to make snap cuts on twigs and small branches i noticed the edge was chipping... I understand why now.
 
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