Killing the edge

[Steve56]

I’ve breadknifed (45 degrees) too Rick, to get rid of/assess devil’s spit. It’s maybe faster than honing it out with a taped spine

 

[Wid]

I’ve breadknifed (45 degrees) too Rick, to get rid of/assess devil’s spit. It’s maybe faster than honing it out with a taped spine

Same here Steve

 

[Loner16]

Just a member of the peanut gallery here....

We really don't know what we're doing, just like to argue the finer points.

 

[silverlifter]

We really don't know what we're doing, just like to argue the finer points.

Easy there, Tiger. I know what I am doing; I'm a freakin' virtuoso at killing edges!

 

[JPO]

A honyama burr from a finisher seems to be a different animal. This tiny burr seems to depend on the steel, stone, technique etc, but there seems to be many ways to remove it.

This is the type of burr I am removing by the light jointing method IF I NEED TO. I usually don't need to.
I am also experimenting with other methods, like you mentioned.
If you have a razor with good steel, and a decent bevel angle it is usually not a problem. Wide and acute bevels are usually more challenging.
I have a test razor that has a too acute bevel angle and a large bevel face. I use this just to test the limits of the steel, and to test different techniques for removing small burrs, or how to avoid the problem.
Stropping on abrasive pastes, adding a layer of tape etc. works just fine. However, for me that is not the point.
The goal is to find a honing method that eliminate the problem in the first place.

I have not tried the dry honing technique.
With flexible hollow grind razors I have had good results by alternating between pressure and light strokes during finishing to avoid the burr from forming. It seems to have the same effect as adding tape, but you need a hard stone to avoid digging into the stone. You are essentially intentionally lifting the apex off the stone to get better contact with your feather light strokes afterwards.

Until I can afford better seats I am doing just fine at the peanut gallery.

 

[Southbound1]

I don’t join or kill edges anymore either. I just found that it wasn’t necessary or produced anything that proper honing wouldn’t produce.

Maybe we’re talking about (at least?) two different things here. If I set a bevel via the burr method (I don’t), then I have a folded over burr made of weak metal. I can scrape that off on a stone, wood, cork, whatever, but I can also hone it off using light strokes flipping the edge each stroke. Either way, I’m in the same place I think.

A honyama burr from a finisher seems to be a different animal. This tiny burr seems to depend on the steel, stone, technique etc, but there seems to be many ways to remove it. Mr Mizuochi and Iwasaki used a pasted strop to remove it. Mizuochi also implied or said in one video that it could be stropped off though others disagree.

Alex Gilmore taught me years ago that a few strokes on a dry hone after finish honing would improve HHT and it does. I use the strokes on the dry hone that Mizuochi used on the diamond strop in his videos. Later on, I was talking with Takeshi Aoki about dry honing improving HHT after finishing, and he immediately began talking about honyama burr removal. I don’t use a microscope so I can’t see the honyama burr, but something happens as a result.

I’m wondering if plain slick cardboard like the inside of a cereal box would work, or newspaper. People have stropped on cardboard for decades. A double/triple layer of newspaper would have some things in common with Iwasaki’s CrOx fabric strop and Mizuochi and Iwasaki the younger’s diamond strop, they’re all flexible enough to hit the apex at a steeper angle than a hone and they’re abrasive.

I have not tried it yet, but suspect that adding a layer of 1mil Kapton and hitting the finisher for 2-3 light strokes would also do it. Give it a try Mike!

Interesting discussion.

I actually tried the cardboard thing years ago, it scratches the bevel badly . My friend, I agree with what you said earlier. Bevel angle has a lot to do with it. Btw i mentioned that too in my earlier post . Steel quality and imo grind thickness has a whole lot to do with it in the equation. You can do a lot more strokes with a finisher on a razor that is thicker behind the edge (quarter hollow etc) You can't take something that 6 thou behind the edge thickness and put a bazillion laps on it with a very fast fine grit synthetic. You can but the edge will no be stable. If you put a bizillion laps then you could breathe on the apex and it would move in the wind because essentlly you would have tin foil and not a stable apex .By the time i get to my 8k i (on a thinner ground razor)may do a max of 25 at the most. At 10-15k i may do 15 on the 10k and 15 laps on the 15k. I don't usually (never used to)hone by numbers but with a hollow ground razor thats again 5-6 thou behind the edge and you can flex the edge profile on tye thumbnail then you got to be careful .

 

[Southbound1]

Just a member of the peanut gallery here....

We really don't know what we're doing, just like to argue the finer points.

Yeap ! Howdy Bill. Working on that coti edge its slow going but it going .

 

[Southbound1]

If you are jointing an edge to remove a burr, micro burr, or flashing, you will remove exactly the same amount of steel or less than if you just “hone” it.

That steel must come off. If you use a piece of wood, or fingernail, or strop it, you break or rip off the burr and then that rough edge must be polished off with a stone or strop.

The benefit of jointing is you make a straight edge and burr free. Then just bring the bevels to meeting at an edge that is already straight.

There is no need to “kill” remove an edge just to make a new one. As said honing with any stone will cut a new bevel and edge.

The largest creator of a burr is the 1k or low grit bevel setting stone. If you grind your bevels flat, in the correct bevel angle and meeting, with stria going all the way to the edge, you will likely have a heavy burr.

Jointing off the burr, a single lap on the face of the stone will remove the burr or make the edge flat and/or weaken the burr so that it will come off cleanly in the next lap. Then bring the bevels back to meeting in less than 10 light finish laps, you will have a straight burr free edge, that you can take to the next stone in the progression.

If you do not joint, you must remove the burr and make the edge straight by honing, the problem is how do you know when to stop honing. Most folks hone way too much. Once the bevels are meeting the edge is as sharp as it is going to get, with that stone. Doing more laps or using more pressure will only thin the edge and or make another burr or an edge that will microchip after a stropping or two.

Jointing is often confused with “killing” an edge, or “Bread Knifing” to remove a chip or edge correction. They are not the same thing. Also Jointing on the flat stone face will remove less steel than jointing on the corner of the stone. Jointing on the stone face spreads the pressure out over a larger area and allows you to use much less pressure and only cut off the burr removing a minimum of steel, and easier to bring back to meeting in fewer laps.

You do not see posts of folks saying I removed a ¼ inch of blade width by jointing my new razor. But the number of posts of new honers grinding razors honing for hours on low grit stones, with lots of pressure, is constant with new honers.

Can one hone a razor without jointing, absolutely. But clearly burr removal and honing too much is an issue for many, that jointing can assist. As said, try it and see if it works for you, if not, Grind On...

I do see the point in joining, i see its purpose and by Jpo's photos of his edges that is proof it is effective. It makes a nice edge. My only concern is join, join join 2-3 times every time you hone it maybe only microns you're removing, but overtime those microns are going to add up to a lot, just depends on how often you hone that particular razor. Its probably unlikely to show up if you have a lot of razors and rarely have to hone. It like having a 50 gallon barrel full of water, and the barrel only has a pinhole, the lose of water is minimal, by over time(sooner than you might think)it will be significant .

Its like always using tape on the spine (BTW i ain't against tape) if you have only one razor in your rotation and everytime you go to the hone you use tape. Over the course of 10 years of removing metal from the blade width and none at the spine then the bevel angle will get obtuse but it take time. Imo - i learned something from A fellows post here years ago on the tape or no tape.He said tape is fine, but we need to be or stay angle aware with the digital calipers. Whenever we see the edge getting to say within 18°-19° (roughly )then its time to hone without tape. I really doubt it would show up in us folks lifetime who have a razor addiction,lol, because we have so many razors and we barley 'need to hone '

 

[JPO]

I do see the point in joining, i see its purpose and by Jpo's photos of his edges that is proof it is effective

The point with these particular photos was just to show how little material you can remove if you are careful.
It does not show that the jointing procedure was needed in this particular case. There was no burr to be removed.
In my example i gently jointed the edge only one time after 12k, on a soft 8k stone. Then i only used a light tomo slurry on my jnat to finish the edge. I did not spend more time on my jnat then i normally do if i use it after a high grit synthetic stone.
So, i do not think i wasted any steel doing this.
If i had finished my synthetic honing on a 6k, i would not joint the edge, because there is no need to.

The edge i got off the jnat looks quite clean, but that does not mean that it will shave better then an edge with some fingerprint left from the 12 Morihei. It might actually be the opposite.

One draw back with doing this is that the normal indicators you look for during honing changes. When you lightly joint the edge and move to your finishing stone the bevel will still be polished. As a result you might experience some resistance on the stone before the edge is ready. It might cause more issues then it solves. Suction to the stone only tells you that your bevel is conforming to the surface of the stone.
It is just one tool you can use, but it is generally best to find a way to avoid having to do it. You don't need to solve a problem if it's not there.


If you joint the edge two or three times during a honing session i do think you are wasting both time and steel.

 

[Southbound1]

The point with these particular photos was just to show how little material you can remove if you are careful.
It does not show that the jointing procedure was needed in this particular case. There was no burr to be removed.
In my example i gently jointed the edge only one time after 12k, on a soft 8k stone. Then i only used a light tomo slurry on my jnat to finish the edge. I did not spend more time on my jnat then i normally do if i use it after a high grit synthetic stone.
So, i do not think i wasted any steel doing this.
If i had finished my synthetic honing on a 6k, i would not joint the edge, because there is no need to.

The edge i got off the jnat looks quite clean, but that does not mean that it will shave better then an edge with some fingerprint left from the 12 Morihei. It might actually be the opposite.

One draw back with doing this is that the normal indicators you look for during honing changes. When you lightly joint the edge and move to your finishing stone the bevel will still be polished. As a result you might experience some resistance on the stone before the edge is ready. It might cause more issues then it solves. Suction to the stone only tells you that your bevel is conforming to the surface of the stone.
It is just one tool you can use, but it is generally best to find a way to avoid having to do it. You don't need to solve a problem if it's not there.


If you joint the edge two or three times during a honing session i do think you are wasting both time and steel.

If you joint the edge two or three times during a honing session i do think you are wasting both time and steel. agreed !!


i know there's no burr, just the typical synth aggression on a thin apex. Jnats do leave a straighter cleaner apex, without joining.
Too agree that the prettiest edges don't always (usually) shave the best, and it's usually the opposite ! I think that a perfect '∆' is not what I am after, its that microscopic rounding that gives the best shave, imo . I guess thats why a 'real linen' is so good for stropping.

I too have experienced that wire edge even on slurried jnat a few times. I would think that a light slurry would introduce a slight convex and eat off the micro-burr (it usually does) but not always.


If you read safely razor(de blades) blade patents, they are honed/ ground with an intensional convex/curve at the very summit/tip of the apex for strength, but it doesn't really cost any lose in sharpness .

 

[JPO]

I too have experienced that wire edge even on slurried jnat a few times. I would think that a light slurry would introduce a slight convex and eat off the micro-burr (it usually does) but not always.

I usually prefer to use something like a jnat after a 5-6k synthetic. If the edge gets too thin and fragile, you can still start to develop an unstable edge, which will depend on the steel and bevel angle etc.
The bevel is stiff at the shoulder and gets gradually weaker towards the edge. That means at some stage the thinnest part is not stiff enough to have enough support to effectively be honed. You are essentially removing steel at a faster rate at the stiffest part of the bevel. That means you will start to develop a burr, which gets increasingly more difficult to remove. As you say, slurry can to some extent offset this, because it acts at the edge. You also compensate be tapering off the pressure as you finish by flexing the grind just enough to offset the pressure.
With e.g. large extra hollow grind blades this can cause issues if it's not managed properly.
You don't want to flex the grind, but it is almost impossible to completely avoid it. The bevel shoulder will act as a fulcrum. It does not take much to skew the pressure over the bevel. You just need to use it to your advantage.
So, if you are removing steel at an uneven rate along the bevel plane, and you are working against a flexbile grind, then you will most likely create a burr if you don't mange the pressure. Removing that burr by jointing is not fixing the problem.

 

[Frank Shaves]

I will gently kill an edge on a beer or wine bottle to prove to myself that I created the edge.

If this is what to breadknife a razor is, no I do not do this:

 

[Southbound1]

I usually prefer to use something like a jnat after a 5-6k synthetic. If the edge gets too thin and fragile, you can still start to develop an unstable edge, which will depend on the steel and bevel angle etc.
The bevel is stiff at the shoulder and gets gradually weaker towards the edge. That means at some stage the thinnest part is not stiff enough to have enough support to effectively be honed. You are essentially removing steel at a faster rate at the stiffest part of the bevel. That means you will start to develop a burr, which gets increasingly more difficult to remove. As you say, slurry can to some extent offset this, because it acts at the edge. You also compensate be tapering off the pressure as you finish by flexing the grind just enough to offset the pressure.
With e.g. large extra hollow grind blades this can cause issues if it's not managed properly.
You don't want to flex the grind, but it is almost impossible to completely avoid it. The bevel shoulder will act as a fulcrum. It does not take much to skew the pressure over the bevel. You just need to use it to your advantage.
So, if you are removing steel at an uneven rate along the bevel plane, and you are working against a flexbile grind, then you will most likely create a burr if you don't mange the pressure. Removing that burr by jointing is not fixing the problem.

You hear some say use torque. Torque at finishing stages can work against you, based on what you said above. I used to try and read a lot how the blade is undercutting the water. I have always heard by certain pros that if you're not undercutting then you're not hitting/honing the very apex.Undercutting can be difficult to read sometimes, because i have had bevels that were no where near being set/done and i would undercut violently. I have noticed to if i frequently wipe the blade and inspect, whenever i go back to the hones the water wants to bead/repel away from the clean metal vs the un-wiped slurry and swarf covered blade, so that can give a false positive and water wants to swell in front of the bevel . I don't pay attention to undercutting during the finishing stages anymore, i just use the lightest touch to keep the edge and spine in contact on the hone. If i want undercut i use jet dry in my water it cuts the surface tension, as @Steve56 recommends

 

[JPO]

You hear some say use torque. Torque at finishing stages can work against you, based on what you said above. I used to try and read a lot how the blade is undercutting the water. I have always heard by certain pros that if you're not undercutting then you're not hitting/honing the very apex.Undercutting can be difficult to read sometimes, because i have had bevels that were no where near being set/done and i would undercut violently. I have noticed to if i frequently wipe the blade and inspect, whenever i go back to the hones the water wants to bead/repel away from the clean metal vs the un-wiped slurry and swarf covered blade, so that can give a false positive and water wants to swell in front of the bevel . I don't pay attention to undercutting during the finishing stages anymore, i just use the lightest touch to keep the edge and spine in contact on the hone. If i want undercut i use jet dry in my water it cuts the surface tension, as @Steve56 recommends

Undercut is just one indicator, and it will depend on allot factors like; how much water, slurry density, surface tension, how fast you move the blade etc. If your stone is soaked with water you might get good undercut even if the blade is far from finished.
I am not sure what the undercut says about the edge condition as an isolated variable.
If you have perfect undercut and strop the razor, the undercut diminishes, as you hone more you get it back. The stropped edge can still be finished.
Undercut on a coticule will be different then on a jnat or a synthetic. It will also wary from synthetic to synthetic.

 

[JPO]

I will gently kill an edge on a beer or wine bottle to prove to myself that I created the edge.

If this is what to breadknife a razor is, no I do not do this:

If you dull it on glass you are more or less just folding over and crushing the edge. Sometimes you can even recover the edge by stropping to some extent. Using an abrasive to clean up the edge is different. The hardness of the abrasive also makes a difference. If you do it with too much pressure on a hard stone you need to take a few steps back to recover it.

 

[H Brad Boonshaft]

In terms of steel removal, it is the same amount steel that must be removed, if you joint the edge or if you hone it off.

If you make a burr or have a jagged edge, the exact same amount of steel must come off. Honing blind, you are likely to remove more steel.

 

[alx gilmore]

japanstones jointing the edge of razor

I now use the rim of a glass jar, or the polished steel bars on my stone holder, to kill the edge, and mostly in the final few strokes of honing a razor. This affects the weak and ultra-thin portion of the edge by just folding it over instead of removing irregular steel representing a false edge. The first couple of passes next when honing on each side of the razor does the deed thereby leaving the edge from heel to toe representing virgin core razor steel. Refining the edge for final keenness will then next be working with solid core steel. Stropping on high-grade leather has no substitute.

Alx

 

[Loner16]

japanstones jointing the edge of razor

I now use the rim of a glass jar, or the polished steel bars on my stone holder, to kill the edge, and mostly in the final few strokes of honing a razor. This affects the weak and ultra-thin portion of the edge by just folding it over instead of removing irregular steel representing a false edge. The first couple of passes next when honing on each side of the razor does the deed thereby leaving the edge from heel to toe representing virgin core razor steel. Refining the edge for final keenness will then next be working with solid core steel. Stropping on high-grade leather has no substitute.

Alx

This is what I always assumed to be taking place. Thanks for verification.

 

[cugel]

What I have done many many times with great success is running the final edge over my thumbnail before stropping. I have taken edges that were not good via hht then thumb nailed them and the hht improved markedly. I take this to mean some deflections remain after my finishing stone and the thumbnail is hacking them off. Too much pressure on the finisher??

 

[JPO]

What I have done many many times with great success is running the final edge over my thumbnail before stropping. I have taken edges that were not good via hht then thumb nailed them and the hht improved markedly. I take this to mean some deflections remain after my finishing stone and the thumbnail is hacking them off. Too much pressure on the finisher??

No matter how good you work is on the finishing stone there will most likely be something for the strop to clean up. The thumb nail might just help to weaken some of this and make the strop more efficient.
Dovo used a piece of wet horn, but I think this was an intermediate step. I don't think this was the last step before stropping.