Sharpening Help Needed

K

Keegaroo

Joined
Jun 26, 2011
Messages
35
I recently got an Ontario Sp2 and decided to give it a little sharpening. I used a 25 degree guide and sharpie to make sure the edge was correct, and I discovered that while one side was perfect the other was far from matching.

So I spent an hour or so trying to get the side to 25 degrees. I believe that it is almost there but when you look at the knife directly it looks to almost have a microbevel, any ideas on how to rid of that so that both sides are perfect? Thanks in advance for any help.
 
Keegaroo said:
Could I also use some very coarse sandpaper in place of the diamond stone?
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Absolutely.

I was reading your post, and contemplating a recommendation. Sandpaper (wet/dry silicon carbide) was among the better options. It works fast, is fairly easy to use, and it's CHEAP! To remove some metal quickly, so the bevels can be evened up, you might start around 220 grit, give or take. If you want to maintain a V-bevel, use a hard backing (like glass or hardwood). Edge-leading stroke, with LIGHT pressure (so the paper won't be cut/torn). If convexing is a possiblity for you, a soft backing like leather, with an edge-trailing stroke will do the job.

Use a magnifier and bright light to inspect as you go, to make sure the new bevels are clean & complete, all the way to the apex of the edge.
 
Obsessed with Edges said:
Absolutely.

I was reading your post, and contemplating a recommendation. Sandpaper (wet/dry silicon carbide) was among the better options. It works fast, is fairly easy to use, and it's CHEAP! To remove some metal quickly, so the bevels can be evened up, you might start around 220 grit, give or take. If you want to maintain a V-bevel, use a hard backing (like glass or hardwood). Edge-leading stroke, with LIGHT pressure (so the paper won't be cut/torn). If convexing is a possiblity for you, a soft backing like leather, with an edge-trailing stroke will do the job.

Use a magnifier and bright light to inspect as you go, to make sure the new bevels are clean & complete, all the way to the apex of the edge.
Click to expand...

I was trying to use a somewhat course sandpaper and it seemed that it would only sharpen the area above the microbevel. I apologize for the questions for I am fairly new at sharpening, also is it possible that I may destory the knife by sharpening it to much.
 
Keegaroo said:
I was trying to use a somewhat course sandpaper and it seemed that it would only sharpen the area above the microbevel. I apologize for the questions for I am fairly new at sharpening, also is it possible that I may destory the knife by sharpening it to much.
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Just take it slow & easy. If you get frustrated or tired, just lay it all down and take a break for a while. Finding the correct angle to get rid of that 'microbevel' is where the magnifier will come in very handy. So long as you take your time, you can get it done. It also helps to use a black marker (like a Sharpie) to darken the edge & microbevel before you start. Make a few light passes on the sandpaper, then inspect with the magnifier to see where the ink is coming off. Based on what you see, you can make adjustments to your angle.

This is a fairly big blade, and thick. It'll likely take some time to take off the metal necessary to even up the bevels. Just approach it at a relaxed pace, don't rush. Patience will always pay off in the end.
 
I think I almost got it, is there any way to confirm that the microbevel is gone besides looking at it directly.
 
Keegaroo said:
I think I almost got it, is there any way to confirm that the microbevel is gone besides looking at it directly.
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Under BRIGHT light, a microbevel or wire edge will reflect light and show up as a bright 'thread' along the very cutting edge. Turn the edge upward, and rotate it around under the light, looking from many angles. If you see that 'thread' of light shining up at you, it's an indicator the edge isn't quite as perfect as it could be. A 'wire edge' i.e., a burr that runs the length of the edge, will also 'shine' in a similar manner. On the other hand, when the edge is perfectly apexed & clean, the edge will seem to 'disappear' when the edge is turned directly towards the light.

And then, there's always the 'cutting' test. Test the edge by slicing some paper. Slice along the full length of the blade's edge, heel-to-tip, into the edge of the paper. Any portion of the edge that either binds (such as on a burr) or slips across the paper without cutting it (still dull/rounded), will need some more TLC.
 
Well, I think I removed the microbevel, but in the process it looks like I accidentaly convexed it...it looks like a semi-convex, I have no clue how as I used the sanpaper on the counter unless it still conformed to make a convex. So, do I finish the convex or leave it?
 
Keegaroo said:
Well, I think I removed the microbevel, but in the process it looks like I accidentaly convexed it...it looks like a semi-convex, I have no clue how as I used the sanpaper on the counter unless it still conformed to make a convex. So, do I finish the convex or leave it?
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Many of us sharpening fanatics actually like that 'accidental' convex. ;) It's natural to the free-hand sharpening process, to greater or lesser extent. The human hands don't generally have such tight control over the angle, when sweeping the blade across the hone. A lot of it comes down to skill & technique. If it cuts, don't worry about it. In time, you might even grow to like it. Convexed edges are VERY EASY to maintain, using the sandpaper and by stropping.
 
The thing is its the side that had the micro bevel that is covexed the other side seems perfectly fine, or is it just the microbevel giving it the appearence of being convexed. Thank you for helping out and understand all of this. I'll try to get pictures up tommorow im still not 100% sure but its decently sharp now shaving but it will do.
 
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Keegaroo said:
The thing is its the side that had the micro bevel that is covexed the other side seems perfectly fine, or is it just the microbevel giving it the appearence of being convexed. Thank you for helping out and understand all of this. I'll try to get pictures up tommorow im still not 100% sure but its decently sharp now shaving but it will do.
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That makes perfect sense. Many knives will actually be 'thicker' on one side, due to asymmetrical grinding. If the blade is examined in cross-section (as if looking straight-on at the tip, with the knife pointed directly at you), there will be more metal on one side of the center line, than on the other side. The 'thick' side usually ends up with a very obtuse edge bevel, which can be difficult to hit when sharpening (unless the angle is raised very high). It's most usually seen near the tip of the blade, which is almost always thicker steel anyway, by design. Always tends to make the user sharpen the area above the edge bevel, which then results in the problem you've encountered. Being that the blade is thicker and more obtuse on one side, it will produce a more pronounced convex on that side.

In order to get the angle evened up on the 'thick' side and flatten the convex a bit, it'll take more metal removal there. The end result will produce a wider bevel (measured from edge to shoulder) on that side, compared to the other. But, the edge will be more symmetrical (angle-wise), and will make a much better cutter.
 
Sharpen with sandpaper on the thick side to even them up and that will even it up. Will it remain convexec? I ask because for now ill keep it a v edge, thank you so much for your help though it is truly indespensible.
 
Keegaroo said:
Sharpen with sandpaper on the thick side to even them up and that will even it up. Will it remain convexec? I ask because for now ill keep it a v edge, thank you so much for your help though it is truly indespensible.
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How much convex remains, is dependant on skill & technique. Don't worry if it's a little bit convex, but just focus on making the shoulder of the bevel a bit flatter than previously (assuming, of course, that's what you want). Any free-hand sharpening method, without the use of guides or jigs, will produce at least some convex. Over time, and with practice, you'll get better at controlling how much convex it produces. If your technique is good (angle control), using a hard backing will lessen the amount of convex, producing something more akin to a V-bevel. If you use soft backing & edge-trailing stroke, more convex will result. Again, that's not a bad thing, so long as you're in control of how much you convex it. A good convex edge is more about rounding off the shoulders of the bevel, but the very edge itself will still be sharp (if done correctly, of course) and essentially 'V' in shape. Focus on making the end of the 'V' as pure and SHARP as you can, and don't worry as much about the convexity of the shoulders.
 
Ok, Ill work on maintaining the 25 degree angle and thatll fix everything or go to about 20 degrees? Leave everything else alone, edge trailing strokes, hard backing and light pressure. Again thanks for helping me through this as Im sure this is a pain for you.
 
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Keegaroo said:
Ok, Ill work on maintaining the 25 degree angle and thatll fix everything or go to about 20 degrees? Leave everything else alone, edge trailing strokes, hard backing and light pressure. Again thanks for helping me through this as Im sure this is a pain for you.
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Whether 20 or 25 degrees, it's up to you. I personally like my edges thinner, and I feel an edge is easier to maintain at a lower angle, easier to 'feel' the bevel on a stone/strop. But, it's all a preference thing. And, with the hard backing, you don't HAVE to use edge-trailing. You CAN, if you feel more comfortable with that. Edge-trailing is generally necessary on soft backing, as an edge-leading stroke is more likely to 'dig in' to the paper & backing, which will cut it (obviously) and will likely dull your edge also.

I don't consider this a pain. I sort of feel like it keeps my brain actively engaged on the subject. That helps ME in the long run, too. :)
 
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