I just blew $80 on an 8k whetstone. Do I really need a 12k whetstone for SR honing?

[Legion]

No, it not one of the Orangies. It is a fairly even midtone grey, from memory. (I have it in storage at the moment. All my honing duties are split between a couple of coticules right now).

It is a very smooth surface, I can tell when it is getting close to maxing the edge, the razor really sticks to the surface when you flip it.

 

[Gamma]

All of my Chugs were less than great.
I hear about those squiggles and how fine those stones are so I keep asking around about them.
I never saw one though.
Ok - so yours isn't squiggly but it's still very fine. Personally - I think you have a hone angel watching over you.
You snagged that gorgeous Verte from Jarrod too.

 

[Legion]

Yeah, that is hone two in my two coti progression.

I think the Cnats are a bit like gold dollars. They range from superb performers, like big Thuringians, to absolute dogs, and everything in between. When I imagine the Cnat mine I have in my mind a bunch of Chinese workers sawing off huge chunks of cliff face, then sawing it into blocks, with very little regard for veins, strata, and whatever. That may be wrong, but I think it is all due to luck which bit you get.

In the same way that BBW's near the Coticule layer have more garnets and can be used for honeing, but the rest of the blue stone is just good for roads or whatever, I'm betting Cnat stone has similar veins and layers, with differing amounts of cutting material within the matrix.

 

[Gamma]

Little or no regard....sounds about right.

 

[xuzxuz]

I use SS 12k. I have also used other 12k+ equivalents, Chinese 12k, 16k shapton, etc.
Speaking from personal experience,
I wouldn't need to use anything higher than 8k to get a shave,
but I certainly wouldn't want to use 8k razor for everyday shave.
I'd prefer to use a fresh disposable.

I've dabbled with crox/diamond/CBN of 12k grain for a good while,
but now I mainly use stones. It's just easier to use and maintain.
If I've saved all the money experimenting with
sprays and leathers and balsas, I could have bought a 12k or more.

 

[SliceOfLife]

The 8k issue has three people who say yea. 1. People who honestly think a shave off a norton 8k is a comfortable, smooth shave. 2. People who don't consider pasted strops to be additional refinement (usually very new honers) who will say that 8k shaves are fine without mentioning that they go from 8k to a .5 micron or less pasted strop. And 3. People who take the stance (like legion), that 8k will cut your beard just fine, so arguably it IS fine, but it's certainly noticeably different from a better edge in use. That logic can of course (as others have already done) be extended to say that basically ANY beveled razor is perfectly fine for shaving with. I've had some Carborundum "razor hones" that I could tell were no higher than 4-5k grit, so obviously if nothing better is available, this level of refinement is considered acceptable.

Where the nays take offense is that group 1 tries to take the agreement of the latter two groups to promote their belief that an 8k shave is perfectly comfortable and smooth. Now I've had people who I know weren't trying to deceive me send me "shave ready" razors that I could tell in an instant were well below 8k refinement, so I'm sure some, perhaps many people would take an 8k edge today and think it's the sharpest razor in existence because they are measuring it against some really bad edges. On the flipside, I have shaved with an 8k edge on a few different occasions, and while it's certainly doable, it will not give me anywhere NEAR as close a shave as I can get with my go to edges (probably the worst of which is a 10k JIS (forget what that'd be on the Norton scale, but probably ballpark 15k-16k)), and if I use my typical speed and techniques in the shave it will be a shave so uncomfortable, I'd have to skip a few days.

Is it impossible that there are guys out there who have access to solid 8k finishes and solid finishes well beyond that who will honestly feel there is little difference in the shave? Of course not, but it's basically the same as the guys who tell you that their Dodge Neon with flame decals on the sides can perform on par with a Ferrari Testiclerossi in a quarter mile. Maybe with them driving both, but 99.999% of drivers will definitely notice a difference. Then these guys seem to convince themselves that the reason others can't appreciate the 8k finish is that they somehow can't finish at 8k, but can finish just fine at a higher grit (which demonstrates a fundamental misunderstanding of honing that I can only believe is willful ignorance on the part of people who otherwise MUST know better).


That said, would I consider an 8k finished straight shave worse than an electric or disposable shave? No. If 8k was all I had or I could buy a bic razor, I'd use the 8k straight. But being better than a disposable for me at this point is hardly an accomplishment. I'd probably go down to 2-3k finish before I'd switch back to disposables, but I'd never suggest to someone that a 2k hone is a suitable finishing stone, to that end, I consider an 8k stone a workable interim stone until you get something better, but you should be looking to get something better once you can. There are many options out there that are not even particularly expensive.


My reference is speaking of 8k on a norton scale (~3micron particle size), an 8k JIS stone is, if memory serves closer to 1.5micron, and will be much closer to what I'd consider an acceptable finish, though I still wouldn't recommend buying one with the intention to use it as a finisher (better options are available at the same or lower price in my opinion).

 

[daflorc]

Daflorc, you seem knowledgable in honing. May I assume you shave off 8k edges only? Which ones do you prefer and what is your progression?

Rickboone, I sometimes finish my own personal razors on an 8k Naniwa, as I really have no NEED to higher in grit. I used to finish all my razors on a coticule. For customers, I always finish my razors on either my thuringian or my jnat - just as a safeguard in case any of my customers are very particular about their edges like Gamma. There is a fine, incremental increase in cutting ability between an 8k and anything higher - after 12-15k, the edge of most blades (minus very hard steels) cannot sustain such a thin edge and will deteriorate quickly - so I've heard from many skilled honers. (I, for one, feel that I can trust the cumulative opinion of a group of guys who all have 20,000 posts on a straight razor forum) and so from that knowledge base I make that assertion. From my own experience, all 8k's are NOT the same, and some are easier to get shave-ready than others. A Naniwa 8k is easy-peasy. kitayama, coticule, nortons are very finicky, and take a skilled hand.


When I'm honing these days, I try to do it as quickly as possible, as I have many razors to hone and ship out. Therefore, the fastest cutters are my favorites. I use a Norton 1k/4k followed by an 8k naniwa. For customers, I follow with either a thuringian or jnat. I sold my kitayama - too slow. I LOVE honing on coticules, as they are just fun, but they also are too slow for my purposes. I like nortons for 1k to 4k work. At the 8k range, I love my Naniwa. It is a fast cutter and provides a smooth edge easily.

I can tell you this:
my first stone was a kitayama. It was a fine-particled stone, albeit a slow cutter. It was harder to get a shave ready edge, but it was possible.
an 8k naniwa is a fast and smooth cutter - period. i use this stone as a benchmark for 8k stones.
My two coticules that I've owned - one fast and one slow - were both slow cutters when compared to my naniwa, however they were capable of giving a great shave, but you really have to know how to work them.
My Norton 8k was a decent cutter, but I sold it because the Naniwas was just superior.
Both the norton and the coticules are very particular - it takes a very delicate touch to use them as fine finishers.
It is much easier to get a smooth, shave-ready edge off the synthetic naniwa.
All these stones require some stropping to really dial in the smoothness of their edges. I prefer 30 laps on natural linen and 40 on leather prior to my first shave. Since I've been restoring and honing razors on a near-full time basis the last year and a half, I've honed and test shaved on around 120-140 razors at this point - most have been old Sheffield steel. It is possible that old (and softer) Sheffield steel lends itself to 8k edges. I can also see new stainless steel razors and razors like CV Heiljestrands, with their harder steels, being able to sustain edges honed to higher grits.

Keep in mind that sharper does not always mean a smoother more comfortable shave. Often times, it just means a harsher edge that will irritate your skin more.

 

[daflorc]

Slice of life, I don't disagree with much that you're saying, except for this excerpt:

"Is it impossible that there are guys out there who have access to solid 8k finishes and solid finishes well beyond that who will honestly feel there is little difference in the shave? Of course not, but it's basically the same as the guys who tell you that their Dodge Neon with flame decals on the sides can perform on par with a Ferrari Testiclerossi in a quarter mile. Maybe with them driving both, but 99.999% of drivers will definitely notice a difference. Then these guys seem to convince themselves that the reason others can't appreciate the 8k finish is that they somehow can't finish at 8k, but can finish just fine at a higher grit (which demonstrates a fundamental misunderstanding of honing that I can only believe is willful ignorance on the part of people who otherwise MUST know better)."

Aside from the obvious condescension in this paragraph, I want to draw your attention to a few facts:

1. An average beard hair is the same strength and hardness as copper wire of the same diameter.
2. The higher the grit, the thinner the steel. Hone your steel too thin (over honing) and that super-sharp edge won't last long, if you consider assertion #1.
3. There are many members on this forum with 1,000-5,000+ posts or more who speak as if they have actual experience honing and shaving with many different stones and razors, when in fact they may not have ever shaved with a straight razor, shaved with only one, or they might only own a 4/8k norton, etc. Yet, extensive reading on the subject and a little bit of experience can give the impression of extensive experience - easily done when typing on an internet forum. I have seen this more than once.
4. Your Dodge Neon vs. Ferrari comparison tells me that you assume that a higher grit edge, which is also a sharper edge, HAS to be a better, smoother shaver. "(which demonstrates a fundamental misunderstanding of honing that I can only believe is willful ignorance on the part of people who otherwise MUST know better)."

I think I didn't start getting consistent edges until I honed 50-75 different straight razors. And for those first 50 or so razors, all I had to work with was: a 1k/4k norton, and either a coticule or a kitayama, or both. I tried using the coticule as a prefinisher before the kitayama at one point. I'd say 1 out of 3/4 razors I could consistently get a super smooth shave out of at the time, and not without effort. By the way, even 50 different razors is a heck of a lot of razors to hone. I'm going to venture and say that most people posting here, despite their claims, have not even handled that many straight razors, let alone honed them. So, no - I don't believe many SR hobbiests are getting the most out of their 8k stones, and seeing as this is primarily a DE forum, I don't believe there are enough SR users here to adequately call members out on BS claims.

Don't get me wrong - there is a small difference in the performance of a perfectly honed 8k edge and a perfectly honed 12k edge, but not so much of a difference that an 8k shave isn't perfectly good and acceptable. That's boloney, and I think I have the experience to back up my claims.

 

[Legion]

This is assuming you subscribe to the theory that using higher grits is making the edge thinner. Which does not actually make sense, as the edge thinness is determined by the angle of the bevel set. All going to higher grits does is polish out the scratches and imperfections of the grit before. Under a microscope the edge does not get "thinner", it just becomes more even and consistent. Unless you are doing something wrong.

 

[Brooksie967]

This is assuming you subscribe to the theory that using higher grits is making the edge thinner. Which does not actually make sense, as the edge thinness is determined by the angle of the bevel set. All going to higher grits does is polish out the scratches and imperfections of the grit before. Under a microscope the edge does not get "thinner", it just becomes more even and consistent. Unless you are doing something wrong.

And then we get to the types of hones we are using and the cutting/vs moving ability of the abrasive. Coticules do to their particle shape and makeup tend to 'roll' the steel and move it, which is why we see people here shaving off of coticules even though their 'abrasive' particles can be 5 - 15 microns.

Bart over on coticule.be wrote something pretty interesting that might have some weight in this thread: A Coticule is not 8000 grit. That's just - understandable - sales talk, inspired by the grit ranges of popular synthetic hones. Allow me to explain: Coticules typically contain garnets in a 5 to 15 micron range. I think we all agree that the largest particles define the actual "coarseness" of a one. Even a Norton 8K will probably contain particles smaller than 3 micron, which is the upper limit of that hone's partical size. Translated to Coticules, that gives us a grit rating of 1500.

This immediately explains why I keep repeating that grit rating is completely irrelevant when we talk about natural hones, a forteriori Coticules. For it is not the width of the abrasive grooves that determines how well a hone can define an edge, but the depth of those grooves. And even that is only part of the whole picture, as I will explain in the next paragraph. Sure, there is a correlation between width of the paricles and their cutting depth, but different shapes of cutting media can make a *huge* difference. It is possible, perhaps even likely, that larger rhomboid garnets cut shallower than smaller ones, for the one reason that their larger surface area doesn't penetrate the steel so easily. This sheds a new light on why Coticules cut entirely differently than synthetic hones with their acute, yet smaller, abrasive particles. It also explains why Coticules demand a different kind of sharpening pressure than synthetic hones. And it indicates that BBW's with their larger garnets are possibly much finer hones than often intuitively expected.

Another largely ignored factor in the final characteristics of an edge, is the amount of plastic flow, that is inherently different between various hones and pastes. "There he goes again". I can almost hear some of you think that. Nevertheless there is no doubt that plastic flow plays a key role in the submicron world where the tip of a razor's edge resides. If not, every edge would carry a saw tooth pattern, defined by the particle size and shape of the finishing hone or paste. Coticule edges would cary a sort of an S-shaped curve, and synthetic edges fine sawtooth pattern. I once followed that idea, even drew up a 3D representtion of it.

While an interesting exercise, the above drawing is pointless, because it completely ignores the effects of plastic flow. As soon as I saw Prof. John D. Verhoeven's SEM-pictures, it became apparent how wrong my drawing was. Verhoeven magnifiied edges up to 3000X with a high resolution scanning electron microscope, and he found no sawtooth pattern, no obvious grooves running all the way up to the very edge, no so-called "striations". What he found was a smooth uninterrupted edge, with a given end-radius, typically arround 0.5 micron for razors. The top of that radius showing a number of elongated burr-like rims. The absence of the expected grooves and teeth can only been explained by plastic flow. As opossed to abrasion, plastic flow does not removes steel, but displaces it, not unlike what we can observe during the cold rolling of steel. It relies on the malleable properties of steel and not on abrassion.

The ratio abrasion/plastic flow is different for each type of working particles. It relies on several factors, interesting enough to treat separately:

1. hardness. Diamond, on one side of the sprectrum, offering a lot of abrasion, and therefor undo's a large part of its plastic action. Chalk, on the other end of the spectrum, being softer than steel, offers minimal abrasion and mostly buffing (read plastic) action. Different hardness is prossibly one of the big factors that makes 0.5 micron diamond paste differ form 0.5 chromium oxide paste.

2. particle shape. Round and smooth shapes being less abrasive and more inclided to roll the steel. This could very well be one of the advantages of Coticule hones.

3. mobility of particles. Particles that are solidly cemented in the surface of a hone, probably offer relatively less plastic action than the more mobile particles on the surface of a pasted strop.

4. applied pressure. More pressure probably favors abrasion. This explains why polishing with buffing wheels, a surface treatment that relies for a significant deal on plastic flow, differentiates between "cutting" (much pressure) and "coloring" less pressure.


I find this all very interesting stuff, but at the same time allow me to be quick to acknowledge, that a well-honed razor, remains a well honed razor, and that I highly doubt any one on these boards can discern between a truly good Cocitule edge and a truly good CrO edge. At least not by one comparative test shave. Perhaps after several shaves, when the difference in longevity between both starts to become apparent. But that has more to do with edge leading (honing) vs edge trailing (stropping) techniques.

 

[Legion]

Very interesting post.

 

[Fuzzy Chops]

The Shapton glass stone 8k edge shown here is flat and has no micro-convexity; however, the edge width is around 150nm. In my experience, 100nm (0.1micron) is the threshold for shaving-sharp. With some stropping this can be made to shave acceptably. In my opinion, this is near the threshold for shave-ready, so sometimes it will be fine, sometimes not quite. In my opinion, this is why there is no consensus on whether 8k is sufficient.




The Coticule edge, shown below, has "deeper' scratches, but the surface is "smoother" More importantly the edge width is below 100nm and will improve with stropping. There is of course some micro-convexity to this edge. Maybe that improves the the smoothness of the shave...

 

[AjaxLepinski]

Brooksie, which Verhoeven paper are you referring to? Is it this one?

http://www.bushcraftuk.com/downloads/pdf/knifeshexps.pdf

 

[pmaster]

I bought a Kitayama 8K water stone. Should I still buy a 12k stone?

Lots of input in here, I'll add mine I started with a naniwa 3/8k. I shaved off the 8k for a while, and I'm pretty darn sure I maxed the edge on the genco I had. It shaved fine, though a bit rough for my taste. Then a member here was nice enough to send me a 1um paper (equivalent to ~12-14k most say), and to be honest, the difference was very big. Of course I had no troubles shaving off 8k, but an edge well finished on 1um made such a difference in getting a nice, easy and smooth shave.

So I would recommend to you to try some 1um lapping film, and see if you get a noticeable difference after the 8k. If so, then you can either stick with film or get some stones. Obviously you better make damn sure that the bevel is well-set and that you extracted all you could from the 8k before.

 

[daflorc]

Fuzzychops, Brooksie - awesome contributions to this thread!

 

[daflorc]

This is assuming you subscribe to the theory that using higher grits is making the edge thinner. Which does not actually make sense, as the edge thinness is determined by the angle of the bevel set. All going to higher grits does is polish out the scratches and imperfections of the grit before. Under a microscope the edge does not get "thinner", it just becomes more even and consistent. Unless you are doing something wrong.

I'm trying to follow your logic here, Legion. In my mind - no matter what the bevel angle is - each side hones down until both sides form a cutting edge thin enough to cut hair. No matter the bevel angle, the more metal you remove on each side of the bevel, the thinner that cutting edge gets.
Let me add to that statement - I know that bevel angle does absolutely play a role in edge thinness. To what extent, I'm not sure. I know we can hone a 3/8" razor to a similar sharpness as a 10/8" blade. If we exaggerate the bevel angle and put 10 layers of tape on a razors spine, I know for sure that the edge will not be as sharp and have reduced cutting ability. I start noticing this at 3 layers of tape on the spine of most wedgy Sheffield razors. However, I do believe that finer honing on higher grits will take an acceptable bevel angle and add additional thinness to the razor edge.

I believe that 95% of a razors shaving ability is wrought from a 1k stone - the bevel set. I also believe that larger grit particles working on the micro-edge of a blade do not allow the very edge to meet its capacity for thinness. Though I do agree that 8k and higher grits polish out the scratches of the previous grit, this polishing is still removing material, which makes the edge thinner, albeit on a very infinitesimal level.

Some steel can handle, at that sub-micron level, that extra thinness at the very edge. Some can't, and will crumble. If you've ever had a razor that just won't get sharp, and the edge seems to deteriorate the higher in grit you go, you know what I'm talking about.

 

[Brooksie967]

Brooksie, which Verhoeven paper are you referring to? Is it this one?

http://www.bushcraftuk.com/downloads/pdf/knifeshexps.pdf

I've seen/read that paper but it wasn't I who wrote that, that's Bart from coticule.be, I just thought instead of trying to capture what he said so well, i'd just steal it and give him the credit. What interested me most was the plastic flow.

 

[Fuzzy Chops]

I've seen/read that paper but it wasn't I who wrote that, that's Bart from coticule.be, I just thought instead of trying to capture what he said so well, i'd just steal it and give him the credit. What interested me most was the plastic flow.

http://www.coticule.be/the-cafeteria/message/10952.html

 

[AjaxLepinski]

http://www.coticule.be/the-cafeteria/message/10952.html

Thanks Fuzzy Chops!

 

[Haggises]

3. There are many members on this forum with 1,000-5,000+ posts or more who speak as if they have actual experience honing and shaving with many different stones and razors, when in fact they may not have ever shaved with a straight razor, shaved with only one, or they might only own a 4/8k norton, etc. Yet, extensive reading on the subject and a little bit of experience can give the impression of extensive experience - easily done when typing on an internet forum. I have seen this more than once.

I've honed precisely ONE razor, so I can't say yay or nay to the 8K argument. If I tried to, I would soon be exposed as a numpty by the fine members of this forum with 1000-5000 posts. Some of them would even be polite.
Please don't read post count as expertise. Look at content and body of work before you paint with a broad brush.