The quest for a sharp edge(Sequel to What causes an edge to roll?) New photos 3/26/14

On those knives, I used 400, 1000 grit stone, then sandpaper 1000 & 1500 grit, then strop on autosol on thick paper (like tissue box). Subsequently, I got balance strop from bluntcut with white compound and washboard, both add further refinement.

Both cut well, sometime I used them to shave.

In my use: The one knife used most often & getting the touch up will be the most refined one. This indicates that the result is not obtained in one session (I'm impatient lol :) ) but from repeated sessions, at least in my case.
 
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Well, I can get the burr to a certain size but after that it just flips. Grr. The burr is small but I just can't seem to eliminate it.

Something else I have noticed. After I raised the spine it generated a bevel at an other angle. I hesitate to call it a micro bevel because it was only a couple of degrees off of the main bevel. Why that fact is important: When I drop back to the original angle, I am having to work the other bevel off. If I use enough pressure to quickly cut it back to the original angle, a new larger burr is generated. Or the old burr flips and becomes larger. If I use light strokes, I am stroking forever and I often don't return the apex to the lower angle. I can tell because the passes made at the original angle do not touch the apex. I can remove all the sharpie from the bevel but I have to raise the spine up to hit the apex again. And if I do make the original angle, GUESS WHAT! New burr. Really, really annoying. Maybe some sleep will help me. Though this problem has happened to me before.

EDIT: This is on the coarse side of my Alum Ox stone. Also, got my Norton Pike stone in the mail! SiC should cut quicker than my Alum Ox on some steels.
 
I think it's said to use enough pressure for the abrasive to cut the burr, but not enough for flipping it. Easier said than done, I know, so keep that in mind.
 
Chris "Anagarika";13352521 said:
I think it's said to use enough pressure for the abrasive to cut the burr, but not enough for flipping it. Easier said than done, I know, so keep that in mind.
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I am not surprised that I am using to much pressure. The other thing is I need to be able to detect the slight change in feedback when the abrasive reaches the edge. And there may be a point when *I* just can not get the burr any smaller.

Strong hand bevel.


Weak hand bevel. Now if I can just deal with that burr.
 
One more thing. A 30* inclusive burr will be created larger & more difficult to remove than a 40* inclusive burr using same pressure. So the more acute you go, the lighter it has to be.

I hope I'm making sense.
 
Squashfan said:
I am not surprised that I am using to much pressure. The other thing is I need to be able to detect the slight change in feedback when the abrasive reaches the edge. And there may be a point when *I* just can not get the burr any smaller.
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Cut way back on the pressure - should be no more than 4-6 ozs at the most. When it comes to grinding off that burr, pressure should be as light as you can possibly manage and still have the abrasive bite. If it gets flipped too many times, is sometimes better to just grind the apex off at right angles and start over. All abrasives need a minimum amount of pressure to work, the burr will tolerate up to a given amount of pressure before collapsing and flipping to the other side. The key is to find the amount of pressure the burr will tolerate and make sure your abrasive is working well enough to efficiently grind off the burr beneath that pressure level. Sometimes this might involve lapping the stone surface if it has become clogged or glazed. Is the number 1 reason why I advocate using (mineral) oil on all vitreous stones, primarily to guarantee the quality of the stone's surface for light pressure work.

The burr is like a door on a hinge, the smaller it is, the less leverage it will have to be flipped. The fewer times its flipped, the stiffer the hinge will be. The steeper the angle of contact with the stone, the more pressure can be applied (or larger margin of error) before it will flip. Larger burrs can be dealt with by elevating the spine and making them into smaller burrs, then lower the spine and deal with them at the original grinding angle but with the burr having less leverage. The key is to stop before the burr flips or the bevel begins to grind at the steeper angle.

Once its gone, additional grinding on the same spot will make a new one form opposite, even with very light pressure. There will be a very short grace period of a few passes maybe between when the burr is removed down to the base angle, and when a new one starts to form, so use short strokes and stop to observe often. Removing the burr in this manner requires a bit of control, but more so just a bit of patience and lots of observation - is worth it for a top notch edge off the stone. If you watch any of my videos (especially ones where I'm working on an oil stone) I'm constantly rolling the edge back and forth across my fingertips to feel for the burr and where on the edge its forming. I don't stop to wipe off the oil for a closer look until I can no longer feel it - by then pretty darn small.

Grind till even burr along one side, flip and repeat, flip and remove. Any additional flips should be to take care of very very small residuals, not to chase larger ones, or it could get away from you and you'll be chasing that flopper all afternoon.

Martin
 
Don't go so far with your tip, your starting to over grind it. The steep rounding and extra belly at the tip area is a indication of too much turning of the blade.
 
HeavyHanded said:
Cut way back on the pressure - should be no more than 4-6 ozs at the most. When it comes to grinding off that burr, pressure should be as light as you can possibly manage and still have the abrasive bite. If it gets flipped too many times, is sometimes better to just grind the apex off at right angles and start over. All abrasives need a minimum amount of pressure to work, the burr will tolerate up to a given amount of pressure before collapsing and flipping to the other side. The key is to find the amount of pressure the burr will tolerate and make sure your abrasive is working well enough to efficiently grind off the burr beneath that pressure level. Sometimes this might involve lapping the stone surface if it has become clogged or glazed. Is the number 1 reason why I advocate using (mineral) oil on all vitreous stones, primarily to guarantee the quality of the stone's surface for light pressure work.

The burr is like a door on a hinge, the smaller it is, the less leverage it will have to be flipped. The fewer times its flipped, the stiffer the hinge will be. The steeper the angle of contact with the stone, the more pressure can be applied (or larger margin of error) before it will flip. Larger burrs can be dealt with by elevating the spine and making them into smaller burrs, then lower the spine and deal with them at the original grinding angle but with the burr having less leverage. The key is to stop before the burr flips or the bevel begins to grind at the steeper angle.

Once its gone, additional grinding on the same spot will make a new one form opposite, even with very light pressure. There will be a very short grace period of a few passes maybe between when the burr is removed down to the base angle, and when a new one starts to form, so use short strokes and stop to observe often. Removing the burr in this manner requires a bit of control, but more so just a bit of patience and lots of observation - is worth it for a top notch edge off the stone. If you watch any of my videos (especially ones where I'm working on an oil stone) I'm constantly rolling the edge back and forth across my fingertips to feel for the burr and where on the edge its forming. I don't stop to wipe off the oil for a closer look until I can no longer feel it - by then pretty darn small.

Grind till even burr along one side, flip and repeat, flip and remove. Any additional flips should be to take care of very very small residuals, not to chase larger ones, or it could get away from you and you'll be chasing that flopper all afternoon.

Martin
Click to expand...

Bold my emphasis. Which answers one of my questions right there. If I have sharpie on the bevel while I am going after the burr with a raised spine, I should stop if the sharpie starts getting removed, right? EDIT: I can still feel something that might be a burr but it is really, really small if it is actually there. Is there something else I could be feeling instead? I am going to break out my loupe and see if I am able to see anything.

I have watched your first India stone video and am 26 seconds into the 2nd video. I got a good idea of what size the burr should be from your comment right there. I may have more questions later.

Knifenut, thanks for the tip!: D
 
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Ok, upon observation what I am feeling appears to be a very, very small micro bevel. Little to no burr over most of the edge. Should I go on to the fine side or work the micro bevel out on the coarse side I have been using?
 
Squashfan said:
Ok, upon observation what I am feeling appears to be a very, very small micro bevel. Little to no burr over most of the edge. Should I go on to the fine side or work the micro bevel out on the coarse side I have been using?
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If its real small, I'd go ahead and on to the fine side. Keep in mind when you switch to the fine side you want to work from the shoulder to the apex. On the side with the microbevel, just remember that it should take a little more time and maybe the bevels will be a skosh uneven, nothing crazy.

Martin
 
Eh, well, I started a new knife last night. Weak hand bevel is wwwaaayyy to low. Which makes me think that I am going to have to load my weak a lot more than my strong wrist. Still have a long way to go.
 
I'm really with heavyhanded in that I stick with my dominant hand and do not switch dominant and weak side hands while sharpening. I really think with some practice it will 'click' and you will end up with much more consistent bevels.
 
Squashfan said:
Eh, well, I started a new knife last night. Weak hand bevel is wwwaaayyy to low. Which makes me think that I am going to have to load my weak a lot more than my strong wrist. Still have a long way to go.
Click to expand...

Is there any way you could post up a video?

Go slow, apply Sharpie and just make a couple of passes - very light pressure - stop and study the results. Study your mechanics and try to pinpoint any slop that might be easily corrected. If you do a better job on some areas of the edge with one hand, study and figure out why it doesn't match on the other side - go for a mirror image. You might be surprised how many little things you are doing differently that can be corrected without much trouble. Ultimately I went with using dominant hand for guidance, and non-dominant hand (fingertips) for fine pressure and angle feedback, both sides. I just couldn't get even performance out of both hands to switch sides, was easier to keep the same hand assignments but with different parameters rather than change assignments.

Shortening the length of each pass or scrub can be very helpful as well - anyone can hold the edge fairly steady on a stone, its when we start to move it that the wheels come off. Shortening your stroke will require smaller corrections to maintain angle control in motion.

Either way, try to look at your mechanics like you might any other manual tool and see where it isn't holding tolerances. Make an angle guide, can be as simple as some lines scribed into your stone block - anything to get you out of the wilderness and into a range where the bevels are clean enough you can feel where you're at in motion.
 
DOH!!! How did I miss this. I have never been able to get the line guides to work for me. I just couldn't bring an imaginary line up through the spine. Or I couldn't get the knife in the sweet spot where the lines would align with the spine correctly. I would use it just like I thought Heavyhanded would. But I still could not get an good readings.

However, I just had a revelation. Hold the block parallel to the floor so the lines are also parallel to the floor. Then bring the knife up and sight it along the lines like the knife is a gun sight. If the knife is out of place, it will not align through the spine and you have to move it until it aligns. And you can get great, clear readings. IDK if the readings are right but it says that the strong side bevel on the new knife is right at 20 degrees. The weak hand bevel varies from 12 to 16 degrees. Heavyhanded, try this out and see if I am crazy. I may just be sleep deprived.

EDIT: I bet this is how Heavyhanded intended it to be all along. I was trying to look at the lines on the block and the knife from the side at a 90 degree angle to both.
 
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On my old block, I'd move the knife on the stone or on the base itself and just estimate approx where the edge begins to catch - then subtract a degree or so figuring the edge isn't going to catch at exactly the same angle. From the back of the block I'd sight down through the spine and line it up with the scribe marks on the base - the longer the lines are, the better they work for a visual indicator. Once you start to work at this angle, can stop and double check every so often, and compare the bevels to the other side as well. You want to establish a flat as rapidly as possible so you can switch over to tactile feedback rather than visual alignment. On a new knife that needs the factory bevels cleaned up, is easy to observe the overgrind pattern and adjust, as long as you stop to check often - every couple of passes. A bit of time on the coarse side of the stone with softer kitchen knives or other cheap cutlery can go a long way toward improving angle control - much better feedback off the larger abrasives, and any changes are fast and clear. My main goal isn't necessarily to hit a given angle with a lot of precision, but to not go higher than a target goal - at or a skosh under is perfect.


0612021226.jpg


One other thought, looking at the pics it appears you're working the bevels so the cutting edge is always perpendicular to the grind path. You might want to try raking the angle a bit, can really help with angle control. Is how I work in my videos etc for easy reference. Is also described a bit in the manual. Diagram is more for compound on paper, but the principles of movement are the same on sandpaper or a stone, just imagine more of a scrubbing fore and aft movement along the indicated path rather than a straight up backhoning, edge leading to deburr.

3e1846d0-6e96-4050-b8ea-12bec9aeb472_zps32dbd1a2.jpg
 
The angle block should help me more now that I actually know how to use it correctly! I am getting better. I can feel it but it is a slow methodical improvement. I really appreciate all the help and kind words.

List of things I need to work on the first knife:

Bevel evenness

Raising less of a burr

Better burr elimination (helped by my previous to do)

Things to try later:

Change the rake of the blade

Strong hand only
 
Squashfan said:
The angle block should help me more now that I actually know how to use it correctly! I am getting better. I can feel it but it is a slow methodical improvement. I really appreciate all the help and kind words.

List of things I need to work on the first knife:

Bevel evenness

Raising less of a burr

Better burr elimination (helped by my previous to do)

Things to try later:

Change the rake of the blade

Strong hand only
Click to expand...

My 2cents (if haven't hit my limit yet..) I'd change the rake path first. This can go a long way toward stabilizing the tool in motion. It also imparts some nice cutting characteristics to the edge. It might seem difficult to tackle, but I believe you'll get good with it pretty rapidly once begun.

If you work the blade in sections it will be far easier to raise a small uniform burr - just stop working on areas as they turn up.
 
Heavyhanded, you and all the other master sharpeners are more than welcome to put in your 2 cents anytime. (In my case, you guys have put in 20 or 30 dollars worth!) I worry that some day you might get tired of trying to help me. I am a better sharpener from this thread. I redid the blackberry machete. I checked for a burr as I worked and raised only a small one. The edge preformed beautifully no damage as long as I limited myself to vines. Did not do well with half inch thick woody stems though. And it was raining a little bit when I was working. I kinda forgot to wipe the machete down so now I have some nice rust on the bevels. Whoops...

Forgot that I also changed my rake path. It did seem to help.
 
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Not sure if others feel the same, but it's good to know you benefit from this interaction. I have to say I also benefit from masters' response here, and very often it results in deeper insight!

You ask questions, then putting the advice to test and back with more questions, and I kept thinking on the probable theory to explain causes, and light bulb pops! lol
 
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