Umnumzaan Sharpening Trouble

[Bugout Bill]

Ok, A week or two ago, I decided to touch up my CRK Star-Tac on my Sharpmaker. It did an ok job, but there was a very stubborn roll on the beginning of the belly portion of the blade that I couldn't sharpen out. After a bit of contemplation, I decided to sharpen the knife last night on my Norton India combo stone. The knife had a rather obtuse edge, so I made the decision to re-profile the knife.

***STUPIDITY BEGINS***

To make re-profiling a more efficient enterprise, I did something rather stupid. I sharpie marked the edge and the corner of the stone to hog off a lot of metal, and it seemed to do a good job. However, after going through the normal sharpening process, I couldn't get the rear portion of the blade as sharp as I felt it could. In fact, the knife really didn't cut any better than it did before the re-profiling, although the knife will shave leg hair.

My question to you all is as follows:

What did I do wrong? Do I need to re-profile the edge more?

Thanks for any input.

 

[L2bravo]

Lot's of variables there man, so pics would help a lot. Just so I understand, you thinnned the edge down a bunch, correct? You did this on the corner of the India stone? Did you smooth this profiled edge, or leave it toothy? Both will get what you want, it's just preference. Is the bevel even? That can make a good bit of difference, in the way that it cuts.

As far as your stubborn roll, use less pressure. That should start thinning it down, to where it goes away. That, or give it a couple of swipes on the 40 degree, and that will cut it off too.

Just so I beat the punch, somebody will be along shortly, to tell you "lightly drag the edge on a piece of wood". That has never done a single thing for me. Not ever. I have my strong doubts, about that working on stuff like S30V, and high wear steels.

 

[Bugout Bill]

Lot's of variables there man, so pics would help a lot. Just so I understand, you thinnned the edge down a bunch, correct? You did this on the corner of the India stone? Did you smooth this profiled edge, or leave it toothy? Both will get what you want, it's just preference. Is the bevel even? That can make a good bit of difference, in the way that it cuts.

I'm sorry about the lack of pics, I'm away from a camera for a while. I'll see if I can post some tonight.

-The edge was thinned out. Sharpie was removed fully along the edge. I had a lot of difficulty removing the sharpie on the very apex of the edge near the rear of the blade however.

-The re-profiling was done with the corner of the coarse side of the stone. The edge was then smoothed out by doing alternating strokes on the corner, at which point it would cut paper. Light was reflective along the edge. I then sharpened normally, although I had difficulty getting the rear portion to stop reflecting light. Eventually, I raised the angle to what it's stock angle was and I was able to get it clean along that portion.

-The edge bevel isn't even, it is wider along the tip and belly. It was that way from the factory too. The edge snagged along this portion until I raised the edge angle too.

-The edge is quite sharp, it will cleanly slice copy paper and shave course hair. It isn't as sharp as it can be though.

 

[HeavyHanded]

Not sure if I'm understanding everything you did. That knife doesn't have a recurve, why would you work the corner? That you had to raise it up to make it clean means you need to do more work along that portion. That is to be expected, the heel and straight portions make greater contact and will generally need more time on the stone than the belly and tip.

Working the corner of a stone that hasn't been smoothed with another stone, will leave you with an extremely coarse grinding surface. Maybe a bit more time on the heel using a flat part of the stone will bring it around.

 

[Bugout Bill]

Not sure if I'm understanding everything you did. That knife doesn't have a recurve, why would you work the corner? That you had to raise it up to make it clean means you need to do more work along that portion. That is to be expected, the heel and straight portions make greater contact and will generally need more time on the stone than the belly and tip.

Working the corner of a stone that hasn't been smoothed with another stone, will leave you with an extremely coarse grinding surface. Maybe a bit more time on the heel using a flat part of the stone will bring it around.

The part in bold answers your own question. Using the corner of the stone allows for very rapid removal of metal. It wasn't the wisest thing to do, but I didn't have my DMT extra coarse with me.

It seems like I'll need to continue re-profiling. How do you know when you've re-profiled "enough"?

 

[HeavyHanded]

The part in bold answers your own question. Using the corner of the stone allows for very rapid removal of metal. It wasn't the wisest thing to do, but I didn't have my DMT extra coarse with me.

It seems like I'll need to continue re-profiling. How do you know when you've re-profiled "enough"?

Using the corner also gives less surface area and makes it tough to control the angle accurately. It will also load up in a hurry. Properly rounded, it makes a great tool for recurves - using it on a flat blade could lead to creation of a recurve. Anyway, the Sharpie on the shoulder is a great idea, just keep at it. When you can blend the bevel at the heel into the bevel along the belly and tip, and raise a burr along the apex, you'll be done. Might take a while on an India stone, but it will get there.

 

[Bugout Bill]

Using the corner also gives less surface area and makes it tough to control the angle accurately. It will also load up in a hurry. Properly rounded, it makes a great tool for recurves - using it on a flat blade could lead to creation of a recurve. Anyway, the Sharpie on the shoulder is a great idea, just keep at it. When you can blend the bevel at the heel into the bevel along the belly and tip, and raise a burr along the apex, you'll be done. Might take a while on an India stone, but it will get there.

Some of the sharpening advice I've seen tends to view using the sharp corner of a stone as being more of an emergency measure than anything else. I did take care to avoid creating a recurve though. Thanks for the advice, I guess patience will be key. I'm using the course side of a Norton India combo stone (I think it is a Crystolon actually) and I has worked well on some other wear resistant steels. I might wait until this weekend so I can use my DMT for this job, but I am kind of weary of diamond stones. The scratches they produce on the edge are a pain to sharpen out.

 

[Sadden]

Maybe? Its still the same abrasive whether you use the top , side or bottom.....

What makes it work a bit faster is the decreased surface area increasing pressure on the contact surface between the stone and the blade. Which you could replicate by simply using more pressure , on the proper portion of the stone. Using the corner like that theres so much room for error that unless your working a recurve (like HH mentioned) then its not worth it.

 

[HeavyHanded]

Some of the sharpening advice I've seen tends to view using the sharp corner of a stone as being more of an emergency measure than anything else. I did take care to avoid creating a recurve though. Thanks for the advice, I guess patience will be key. I'm using the course side of a Norton India combo stone (I think it is a Crystolon actually) and I has worked well on some other wear resistant steels. I might wait until this weekend so I can use my DMT for this job, but I am kind of weary of diamond stones. The scratches they produce on the edge are a pain to sharpen out.

If its a Crystalon, you should have a reasonably easy time, even on high carbide steel. Maybe some oil, WD40, or windex will keep it grinding faster, the mud helps prevent larger scratches and keeps burr formation to a minimum. Bottom line...more elbow grease.

 

[Bugout Bill]

If its a Crystalon, you should have a reasonably easy time, even on high carbide steel. Maybe some oil, WD40, or windex will keep it grinding faster, the mud helps prevent larger scratches and keeps burr formation to a minimum. Bottom line...more elbow grease.

The Norton India Combo stone consists of a Crystolon medium and an India Fine side. Excellent stone, I've had no problems on S30V with it. I run the stone wet, it was degreased shortly after I got it.

 

[bgentry]

-The re-profiling was done with the corner of the coarse side of the stone. The edge was then smoothed out by doing alternating strokes on the corner, at which point it would cut paper. Light was reflective along the edge.

If you mean that looking straight down at the cutting edge, you could see light reflected, that means you did not apex the edge. You may have done a good bit of metal removal, but you most certainly did not finish the bevel.

I then sharpened normally, although I had difficulty getting the rear portion to stop reflecting light. Eventually, I raised the angle to what it's stock angle was and I was able to get it clean along that portion.

I've had experience reprofiling blades that had badly ground bevels in different spots. Several have had very obtuse angles at the very back portion (the rear, near the choil). I've had to spend considerable effort to make the bevel even on those blades. Spending literally 5 to 10 times the effort on the last 1/2 inch of the blade to get the bevel totally even. By this, I mean that the entire bevel has the same angle, which means grinding the crap out of the rear portion if it was sharpened to a higher angle (which is how several of these blades were).

It sounds like you "cheated" by matching the original angle after doing a bunch of grinding and trying to make it all one angle. You asked in a later post "how do you know when the reprofiling is done?" The answer is always the same: When all the sharpie is gone from the entire bevel *and* you've formed a full length burr.

Something that surprised me, was reapplying sharpie, doing some grinding, and then looking at the edge bevel (the side where the sharpie mark is) with a loupe. I found in several areas where I thought *all* the sharpie was gone, it wasn't. There was a whisper thin line of sharpie left at the edge because I wasn't *all* the way to the edge yet! On at least one blade, the difference between when I thought the sharpie was gone and when it really was gone, was quite a bit of grinding. It also resulted in an edge that shocked me with it's sharpness. This was one of the big Ah HA! moments for me.

Until you do both those things, you won't have one clean flat bevel. I'm not sure what you have exactly right now. Perhaps a microbevel on the rear portion. Perhaps a microbevel on the whole thing. Microbevels aren't bad; it's just not the same thing as a full reprofile using one angle and forming one bevel that apexes the edge.

Re-reading this my tone seems sort of harsh and I didn't mean that at all. I'm just trying to share my experience with this, and these last two points (all sharpie gone, FULL LENGTH burr) were enormously important in my sharpening progress.

I wish you good luck.

Brian.

 

[Bugout Bill]

EDIT: Nevermind, I got one side where I want it.

 

[Omega Leather Works]

Just so I beat the punch, somebody will be along shortly, to tell you "lightly drag the edge on a piece of wood". That has never done a single thing for me. Not ever. I have my strong doubts, about that working on stuff like S30V, and high wear steels.

You're probably right about it not working on certain steels, in fact I'd bet money on it.

I wouldn't suggest to someone that it doesn't work at all though. I've had it work quite nicely on very acute carbon steels. My Opinel and one of my 1095 carving knives are two examples.

Op, glad you got it worked out. I have had a hell of a time with Spyderco s30v, but haven't sharpened much CRK steel. Only one s35vn Sebenza, and that one I only brought the angle down a few degrees. Reprofiling is nasty sometimes because you are removing a lot of steel, all of which is resistant to getting to the apex. One reason why it's easier to cut directly into a stone when repairing a chipped edge.

 

[Bugout Bill]

You're probably right about it not working on certain steels, in fact I'd bet money on it.

I wouldn't suggest to someone that it doesn't work at all though. I've had it work quite nicely on very acute carbon steels. My Opinel and one of my 1095 carving knives are two examples.

Op, glad you got it worked out. I have had a hell of a time with Spyderco s30v, but haven't sharpened much CRK steel. Only one s35vn Sebenza, and that one I only brought the angle down a few degrees. Reprofiling is nasty sometimes because you are removing a lot of steel, all of which is resistant to getting to the apex. One reason why it's easier to cut directly into a stone when repairing a chipped edge.

Eh, I've realized that I didn't get one side fully reprofiled. Same problem, the very rear still isn't getting apexed. Back to the stone I guess.

 

[HeavyHanded]

Eh, I've realized that I didn't get one side fully reprofiled. Same problem, the very rear still isn't getting apexed. Back to the stone I guess.

If you aren't already, it really helps to have the fingertips of your off hand (hand that isn't holding the handle) right on the spot where you are grinding. If you're using full sweeping motions on this sort of work, you might want to try changing to more of a scrubbing motion (think Murray Carter). It is much more conducive to applying work where its needed and wasting less energy and steel. If you already grind in this manner, carry on good sir - nothing a bit of elbow grease won't set right.

 

[Omega Leather Works]

I agree with HH. Only thing I'd add is to be careful not to let your fingertips slide down to the edge. Edge leading with your fingertips caught between the stone and apex can ruin your day. Don't ask me how I know!

 

[Bugout Bill]

Alrighty, I'm pretty sure I got it this time. I took HH's advice and put my fingers right along the edge and used scrubbing motions, got all the sharpie off the edge. I still need to refine the edge a little bit more, but it cuts much better. Thanks for all the advice guys.

 

[evanPGH]

Wait...so you reprofiled with the MEDIUM stones?!

Jeez man I tip my hat to you, I repfrofile with the diamond rods and even that is time consuming enough. I spent over an hour grinding off the convex edge on my SR-1 but it's definitely worth it.

 

[Bugout Bill]

Wait...so you reprofiled with the MEDIUM stones?!

Jeez man I tip my hat to you, I repfrofile with the diamond rods and even that is time consuming enough. I spent over an hour grinding off the convex edge on my SR-1 but it's definitely worth it.

No, not the spyderco medium rods. A norton medium crystolon stone; totally different beast. Excellent stone though.

 

[evanPGH]

No, not the spyderco medium rods. A norton medium crystolon stone; totally different beast. Excellent stone though.

Oh ok thank god haha...I was a little worried there, I couldn't imagine how long that would take.