How is it possible?

[Tomo]

How is it possible that an edge gets sharper after using it?

Last night I spent some time reworking the edge on a new rescue razor. I got the razor shaving well but there was still a small section of the toe missing an edge. I also noticed a few little chips that I hadn’t cleaned up 100% in my initial honing effort.

Progression was

Shapton HR 500 -> 1k -> 3k -> 10k -> Thuri (slurry to water dilution)

I went through the motions observing and testing as I went. Everything looked sweet. Chips were cleaned up, no reflections looking straight down on the edge at 10x, honing scratches cleaned up nicely and evenly. Tomato test and finger nail tests were all good. But then the moment of truth. Stropping and HHT. Meh HHT… Meh tree topping... Kind of worked but not really there if you know what I mean.

Determined to get it right this time, I ran the progression again. And again… With the same result. The HHT was kind of weak. Tree topping would pop the odd hair but that was it. Everything looked good but the tests were off.

Eventually, after staying up way too late, I gave up and resolved to test the edge in the morning with a good blade on standby. The first few shave stroke felt ok. No tugging. Is this thing even cutting? Yes it is. Nice and smooth with lots of stubble on in the lather. So I continued using it with no need for the standby razor. Rinsed off and had a feel round my face. Nice shave.

Then out of interest I tested the razor again (without stropping). Now the razor was tree topping brilliantly. After stropping it was singing.

What’s going on here? The only thing I can think of is that shaving removed some sort of burr from the edge. It looked a lot like the @cotedupy video where he tests a knife before and after sawing through a cardboard roll. The ‘dull’ knife suddenly becomes sharp after it is deburred.

Am I missing a deburring step in my honing?

A few other observations.

1. After a failed stone progression, I will often fall back on lapping film and balsa. The Method edge always passes the HHT at the end. One difference is that I will incorporate lateral “pull strokes” in line with The Method doctrine.

2. I often notice improvement in razor edges after a few ‘shave-touchup’ cycles following a big honing session.

Any idea what’s going on here?

 

[captaincaed]

I'm still learning to hone so huge grain of salt. I never have a finished edge straight off the stone. Never tree tops. After stropping, all good.

Your face is basically leather, maybe it’s helping?

With knives residual burr is the culprit 99 times in 100 when you’re pretty sure you have a good edge, but doesn’t perform. Rip it off, a few more edge leading strokes to reform the apex, and it’ll be fine. Cotedupy’s vid was an awesome display.

 

[Legion]

did something change with the hair you were using for the HHT?

 

[Tomo]

did something change with the hair you were using for the HHT?

Quite possible. My hair supply is uncontrolled. Just whatever I can pull out of my wife’s or daughter’s hair brush. It could be clean or greasy. No idea if they used some kind new conditioner either.

My leg hair should be quite consistent although the morning test was straight after a shower.

 

[Legion]

That could be it. Straight after the shower, hair hydrated and softer, the scales on the hair standing up to get caught by the edge.

For best consistency, wait until your daughter washes her hair, then cut a small lock from underneath where it wont show (don't let your wife see) and keep it in a bag. That way you know it was all the same and it removes a lot of variables.

 

[Steve56]

Determined to get it right this time, I ran the progression again. And again…

You honed so long that you got better at honing? <- humor

 

[JPO]

How is it possible that an edge gets sharper after using it?

Last night I spent some time reworking the edge on a new rescue razor. I got the razor shaving well but there was still a small section of the toe missing an edge. I also noticed a few little chips that I hadn’t cleaned up 100% in my initial honing effort.

Progression was

Shapton HR 500 -> 1k -> 3k -> 10k -> Thuri (slurry to water dilution)

I went through the motions observing and testing as I went. Everything looked sweet. Chips were cleaned up, no reflections looking straight down on the edge at 10x, honing scratches cleaned up nicely and evenly. Tomato test and finger nail tests were all good. But then the moment of truth. Stropping and HHT. Meh HHT… Meh tree topping... Kind of worked but not really there if you know what I mean.

Determined to get it right this time, I ran the progression again. And again… With the same result. The HHT was kind of weak. Tree topping would pop the odd hair but that was it. Everything looked good but the tests were off.

Eventually, after staying up way too late, I gave up and resolved to test the edge in the morning with a good blade on standby. The first few shave stroke felt ok. No tugging. Is this thing even cutting? Yes it is. Nice and smooth with lots of stubble on in the lather. So I continued using it with no need for the standby razor. Rinsed off and had a feel round my face. Nice shave.

Then out of interest I tested the razor again (without stropping). Now the razor was tree topping brilliantly. After stropping it was singing.

What’s going on here? The only thing I can think of is that shaving removed some sort of burr from the edge. It looked a lot like the @cotedupy video where he tests a knife before and after sawing through a cardboard roll. The ‘dull’ knife suddenly becomes sharp after it is deburred.

Am I missing a deburring step in my honing?

A few other observations.

1. After a failed stone progression, I will often fall back on lapping film and balsa. The Method edge always passes the HHT at the end. One difference is that I will incorporate lateral “pull strokes” in line with The Method doctrine.

2. I often notice improvement in razor edges after a few ‘shave-touchup’ cycles following a big honing session.

Any idea what’s going on here?

I have had the same issue a couple of times. The shapton 10k is a fast stone. You might be creating a small burr that is difficult to see with your loupe. After the 10k you should pass all your tests with ease. I would not go to the Thuri before you have a good edge already.
I have had good results if i do some light stropping on linen, with a little play in the strop. After that i go back to my 8-10k to finish the edge with just a few strokes. Now the Thuri should smooth out the edge nicely.
I have also had good results by doing just 5-10 strokes on balsa, and going back the the finishing stone to get the edge "back".

Sometimes i get this problem if i stay to long on a really hard JNAT. It might just be caused by inconsistency in my honing by doing more work on one side of the bevel, maybe.

It would be interesting to know how they deburr and create the final micro bevel on DE and SE artist club blades. This is from a Gillette Platinum DE blade. Notice the striations parallel to the edge where the micro bevel starts. It is probably not that relevant to the discussion. I just found it interesting

 

[macintoshBR]

The only true test is the shaving test.

 

[cotedupy]

You, and others, have already hit on a few of the possibilities here. Some observations...

When you hone a razor you're playing at the upper echelons of how sharp people can make a blade by hand (without machinery), and have it still be useful for something. The edge is so delicate that for almost any other application we would call it a wire edge, or burr. It's fragile and tiny, tiny little things affect it.

The 'normal' motion of stropping a razor on leather using back and forth strokes at 90 degrees is the kind of thing that gives a very sharp edge. It doesn't give you a particularly stable one, because it involves pure edge trailing strokes. If you start throwing in X strokes, or small variations in how tight the strop is pulled, i.e. the level of deflection, then you will gain refinement and stability, but sacrifice a small amount of overall sharpness. If you can do this and still get a nice silent HHT then you're onto a winner. The same principal as pull strokes on balsa.*

It's absolutely possible that the act of using a razor has affected the alignment of the edge in a way that the initial stropping didn't. And that after a couple of shaves and strops the edge is better aligned and more refined than it was initially. It's probably not ideal to have this situation, and a bit more time on a finishing stone and stropping might've helped. And again - diamond balsa would I'm sure have sorted very well too, as you've noticed T.

HHT is a very good way to assess the edge of a razor, it's extremely accurate. But because of that it's also highly sensitive, and again - tiny changes affect it. And it's less reliable (or perhaps more sensitive) as the bevel angle decreases, HHT on very thin edges or super hollow grinds can be erratic. Despite all of the stuff I've said above, I think the most likely explanation for the original q. is variation in the hair.




* Calling it 'deburring' is perhaps a slight misnomer, because at this stage it's probably more like alignment of the burr or edge. If you actually had a razor that really needed deburring in the traditional sense at the end of honing, then you'd be screwed. Though that is kinda a matter of how you define things, and some people may do so differently.

 

[JPO]

I tink @cotedupy has a good point with respect to how fragile the edge is at this stage. At 10 to 12k you are quite close to what some steels can support a given bevel angle. After 10k your finishing stone does not have much to work with. For some reason i usually get better results if i move to a natural stone (not counting the Arkansas in here) from something like an 6-8k synthetic.
At 10k i feel like i have made the decision to go for a synthetic edge, but i do not have much experience with Thuringians.
I have tried going from a 10k to a JNAT, but these are much faster then most Thuringians. I ended up creating a false edge even with slurry.

 

[H Brad Boonshaft]

It’s the burr, and basically you face stropped it.

So, a few key words that got my attention.

“Reworking the edge on a new rescue razor. I got the razor shaving well but there was still a small section of the toe missing an edge. I also noticed a few little chips that I hadn’t cleaned up “

Rescue Razor, missing edge, chips, to me indicate steel issues, or edge repair needed. It may not be a simple honing.

I first joint the edge on new to me razors and look straight down on the edge. I am looking for dark spots in the shiny flat edge. Dark spots indicate chips or weak steel. It is a warning that edge repair may be needed. A solid shiny flat edge indicates good solid steel.

I also ink the bevels to see if the razor will sit flat on the stone. I want to get as much information about the razor, before I invest a lot of time in it. These simple, quick tests will tell me if the razor needs regular honing or if there are repair issues that may need attention before honing.

Then I set the bevel fully and joint the edge again, looking for dark spots. If I continue to see spots, I re-joint and re-set until I get down to clean steel, removing microns of steel at a time.

This is the opposite of what you want to see when looking at an edge to see if it is fully set, where you are looking for shiny reflections.

There is a difference between repair work and regular honing, sometimes we get away with just honing and removing enough material, sometimes you get an edge, but it will not last. It crumbles after a few shaves and stropping. Stropping will flex the edge and if it is weak it will fail.

Surgeons use the term, Cutting to the margins. Removing all the damaged tissue and a little more to get to good tissue that will heal. The last thing they want to do is have to go back in and cut more because they did not cut deep enough the first time.

Jointing and looking at the edge will tell you a lot about the condition of the edge and steel. You are not removing excess steel, you will remove less steel than just honing, hoping to get to good steel. Hope is not a plan.

So, burr, (there is always a burr) was bent the wrong way from the last stone. It would have been interesting to have flipped the razor and see if it would cut hair.

I suspect you have a weak burr, and your face was enough to straighten it out, stropping on leather straightened it out even more. Will be interesting to see how long it last.

Stropping between stones, especially after bevel setting will make a straighter edge faster, and I believe a stronger one. I strop on firehose when honing, but linen will do much the same thing.

I have been experimenting with a tan Flax linen, Tony Miller strop with great results, may be as good as firehose.

 

[lightfoot]

Using a few pull strokes might help for post-finishing.

 

[cotedupy]

Hope is not a plan.

Made me laugh, I might steal that one.

Stropping between stones, especially after bevel setting will make a straighter edge faster, and I believe a stronger one.

I've never tried this, but I like the idea. The theory is completely sound, and it seems like an obvious thing to do now that you mention it. Will start using.

 

[Darth Scandalous]

Hope is not a plan.

I call it "faith-based honing."

 

[cotedupy]

The kind of thing one of my schoolteachers would've yelled.


- And what exactly do you think you're going to achieve by adding the reagent at this point, boy?

- Err... I was hoping...

- HOPE IS NOT A PLAN!!!

 

[Bowmaker]

You, and others, have already hit on a few of the possibilities here. Some observations...

When you hone a razor you're playing at the upper echelons of how sharp people can make a blade by hand (without machinery), and have it still be useful for something. The edge is so delicate that for almost any other application we would call it a wire edge, or burr. It's fragile and tiny, tiny little things affect it.

The 'normal' motion of stropping a razor on leather using back and forth strokes at 90 degrees is the kind of thing that gives a very sharp edge. It doesn't give you a particularly stable one, because it involves pure edge trailing strokes. If you start throwing in X strokes, or small variations in how tight the strop is pulled, i.e. the level of deflection, then you will gain refinement and stability, but sacrifice a small amount of overall sharpness. If you can do this and still get a nice silent HHT then you're onto a winner. The same principal as pull strokes on balsa.*

It's absolutely possible that the act of using a razor has affected the alignment of the edge in a way that the initial stropping didn't. And that after a couple of shaves and strops the edge is better aligned and more refined than it was initially. It's probably not ideal to have this situation, and a bit more time on a finishing stone and stropping might've helped. And again - diamond balsa would I'm sure have sorted very well too, as you've noticed T.

HHT is a very good way to assess the edge of a razor, it's extremely accurate. But because of that it's also highly sensitive, and again - tiny changes affect it. And it's less reliable (or perhaps more sensitive) as the bevel angle decreases, HHT on very thin edges or super hollow grinds can be erratic. Despite all of the stuff I've said above, I think the most likely explanation for the original q. is variation in the hair.




* Calling it 'deburring' is perhaps a slight misnomer, because at this stage it's probably more like alignment of the burr or edge. If you actually had a razor that really needed deburring in the traditional sense at the end of honing, then you'd be screwed. Though that is kinda a matter of how you define things, and some people may do so differently.

I kind of suspect an inconsistent HHT test also.

I have found a huge difference in the HHT depending mostly on who's hair is used but there is much more to it.

coticule.be

This domain may be for sale!

www.coticule.be

My hair is a little easier than my wife's, my daughters is easier than mine, my son in laws hair feels like I'm cheating.

 

[FarmerTan]

Tomo: wait until your wife is soundly sleeping, then pluck one of her hairs.

I'm SURE that she will sleep through it my friend!

 

[Tomo]

It’s the burr, and basically you face stropped it.

So, a few key words that got my attention.

“Reworking the edge on a new rescue razor. I got the razor shaving well but there was still a small section of the toe missing an edge. I also noticed a few little chips that I hadn’t cleaned up “

Rescue Razor, missing edge, chips, to me indicate steel issues, or edge repair needed. It may not be a simple honing.

I first joint the edge on new to me razors and look straight down on the edge. I am looking for dark spots in the shiny flat edge. Dark spots indicate chips or weak steel. It is a warning that edge repair may be needed. A solid shiny flat edge indicates good solid steel.

I also ink the bevels to see if the razor will sit flat on the stone. I want to get as much information about the razor, before I invest a lot of time in it. These simple, quick tests will tell me if the razor needs regular honing or if there are repair issues that may need attention before honing.

Then I set the bevel fully and joint the edge again, looking for dark spots. If I continue to see spots, I re-joint and re-set until I get down to clean steel, removing microns of steel at a time.

This is the opposite of what you want to see when looking at an edge to see if it is fully set, where you are looking for shiny reflections.

There is a difference between repair work and regular honing, sometimes we get away with just honing and removing enough material, sometimes you get an edge, but it will not last. It crumbles after a few shaves and stropping. Stropping will flex the edge and if it is weak it will fail.

Surgeons use the term, Cutting to the margins. Removing all the damaged tissue and a little more to get to good tissue that will heal. The last thing they want to do is have to go back in and cut more because they did not cut deep enough the first time.

Jointing and looking at the edge will tell you a lot about the condition of the edge and steel. You are not removing excess steel, you will remove less steel than just honing, hoping to get to good steel. Hope is not a plan.

So, burr, (there is always a burr) was bent the wrong way from the last stone. It would have been interesting to have flipped the razor and see if it would cut hair.

I suspect you have a weak burr, and your face was enough to straighten it out, stropping on leather straightened it out even more. Will be interesting to see how long it last.

Stropping between stones, especially after bevel setting will make a straighter edge faster, and I believe a stronger one. I strop on firehose when honing, but linen will do much the same thing.

I have been experimenting with a tan Flax linen, Tony Miller strop with great results, may be as good as firehose.

Thanks to everyone for the considered replies. It was a strange phenomenon and may have been the result of a combination of factors.

I’ve recently added the jointing into my honing and will now try adding the linen stropping between stones. I’m certainly guilty of using the “hone and hope” approach sometimes. When you’re honing for yourself you have the luxury of having as many attempts as you like. A more scientific approach would get the job done faster. The imperfections are just so much easier to see once the final polish has been applied.

I couldn’t resist an Arkansas touchup so I didn’t get a chance to see how long the edge would last. All roads lead to Arkansas at the moment. One more Bengall has been saved from the scrap heap.