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Variance...

Matt

Well-Known Member
Yesterday I spent over half an hour on my
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... - all I got was a spine wear, dammit. I started to play with hybrid slurry, but seeing it yields no results whatsoever I switched to regular Coticule slurry, and still I couldn't even get the properly shaving bevel... I gave up and just put everything away not to wear the gear any longer. Is this just my lack of experience or everyone experiences it from time to time (I bet it's the 1[sup]st[/sup], to be honest :lol: )?

BTW, I noticed that I'm getting more consistent results with my
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. I guess I screw up something with the stroke on the n[sup]o[/sup] 25, especially its narrow end. >Sigh< That brings back Ralfy's wise words I read about sending all other hones far away to someone you trust... And you guys ask me how
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stone performs? :)

kind regards,
Matt
 

Bart

Well-Known Member
matis said:
Yesterday I spent over half an hour on my
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... - all I got was a spine wear, dammit. I started to play with hybrid slurry, but seeing it yields no results whatsoever I switched to regular Coticule slurry, and still I couldn't even get the properly shaving bevel... I gave up and just put everything away not to wear the gear any longer. Is this just my lack of experience or everyone experiences it from time to time (I bet it's the 1[sup]st[/sup], to be honest :lol: )?

I think your problem is lack of experience. I'm going to tell you a story that I may have told before.
Every once in a while I get a question about sharpening razors, by someone who lives within car traveling distance. I usually invite him over at my home, because I have found that I can teach more in a couple of hours at home, than by spending a multitude of that time answering e-mails. When the lesson starts, I put my stereoscope on the kitchen table, and start working on the dullest razor that the person brought with him, preferably some piece won on Ebay, that already cost the new owner serious frustration.
The first thing I explain is that, no matter the hone used, nothing will truly happen at the very edge before the razor has flat bevel faces that are fully developed. Often they know that already, but that does not mean they also realize it.
[img=400]http://www.coticule.be/tl_files/barts_pics/steel_removal-cuting_bevel.jpg[/img]

With the scope you can very clearly see how the "sandblasted" pattern, left by the Coticule, slowly grows, starting from the bevel boundary. It often happens on razors with bevel completely out of wack, that it takes me 15 minutes and it's still not done. If I were on my own, I would go get my 600 grit DMT at that point. But almost without exception, the "student" (if I'm entitled to use that word) takes another look at the scope and declares that the work is nearly done. They see 3/4 of the bevel width covered with the Coticule pattern. Only 1/4 to go. Let's do math: 3/4x=15min. => x=(15min*4)/3=20min. Hence, only 5 minutes left to complete the bevel. Right? Wrong.
The "worn" bevel is always the most rounded near the very edge, hence we need to plow deeper to get that final part flat. But not only do we need to remove a thicker layer of steel, we need to remove that layer from the entire surface already done. Conclusion: we might still have the bulk of the work ahead of us... As I said, many know, few realize.

I have known to spend over an hour on a fast Coticule to set a bevel, granted, that was before I used pressured halfstrokes. People will tell you that you should do that kind of work on a 1K hone, but I guarantee you that you'll experience the same, because that one isn't necessarily faster than a Coticule with slurry. When the 1K takes to long, they'll attribute it to the steel of the razor, certainly when there are myths supporting that claim, like the so-called resistance of stainless steel against abrasion. Or the reputation of certain brands of Sheffield razors, not surprisingly wedge-types.



On the other end of the spectrum, we have a razor in service. It has a flat bevel. You have been shaving with it for quite some time, done a few touch-ups on the Coticule, and now you decided that it 's in need of a full honing. There will be no, or almost no, convexity in the shape of the bevel. There's only some structural micro-damage at the very edge, caused by impact with literally millions of beard hairs. You might dull on glass, and by the time you're back at shaving arm hair level, the structural micro-damage is gone as well. You know that will not take you much longer than a couple of minutes to achieve. If not, something is very wrong with your honing stroke.

If your razor was maintained with pasted stropping, the bevel condition would be anywhere between those extremes I've described here.

It is all a matter of being able to assess what the razor needs, and the confidence that you are capable of dealing with it. Too many people don't look at the razor. I mean: they see it, but they don't really look.


In other words, you've stated that you spend over half an hour at the hones, but what you didn't state is what the razor needed.
Something tells me you didn't really made that assessment. (Please correct me if I'm wrong). If it means anything, I never hone on a razor without forming a good idea what I'm looking at.
Magnification helps, but a good light source can tell a lot as well. Just make it shine over your shoulder while you hold the razor, edge facing up, in front of you. Twist and turn, allow the light to reflect of the bevel into your eyes. A good bevel does that only at one angle. Twist it by the smallest amount, and the reflection no longer hits your eyes. A round bevel, shatters the light in many directions. A partial bevel shows both conditions: a reflection adjacent to the bevel boundary that shines in one direction, and a part near the very edge that doesn't.
If the razor has no completely flat bevel, stay at it. Use a coarser hone, if it takes too long, or do it on the Coticule, if you like the calming effect of a honing session. Do check often. Tape the spine, if you worry about wear (I almost never do that). Keep an eye on the edge curve. Remember that the next complete bevel never lies past the current apex of the razor (unless the razor has a convex bevel, but that is extremely unlikely). If a part stays behind, don't be afraid to place your finger on it.

matis said:
BTW, I noticed that I'm getting more consistent results with my
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. I guess I screw up something with the stroke on the n[sup]o[/sup] 25, especially its narrow end. >Sigh< That brings back Ralfy's wise words I read about sending all other hones far away to someone you trust... And you guys ask me how
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stone performs? :)
Keep the narrow end of that hone pointing towards you. It will be easier.

Kind regards,
Bart.
 

Matt

Well-Known Member
Hello,

Magnificent post, Sir Bart. Thank you very much.
Bart said:
I think your problem is lack of experience. I'm going to tell you a story that I may have told before. (...)
I have known some parts of this story, but not all the details until now. :)
Bart said:
On the other end of the spectrum, we have a razor in service. It has a flat bevel. You have been shaving with it for quite some time, done a few touch-ups on the Coticule, and now you decided that it 's in need of a full honing. There will be no, or almost no, convexity in the shape of the bevel. There's only some structural micro-damage at the very edge, caused by impact with literally millions of beard hairs. You might dull on glass, and by the time you're back at shaving arm hair level, the structural micro-damage is gone as well. You know that will not take you much longer than a couple of minutes to achieve. If not, something is very wrong with your honing stroke. (...) In other words, you've stated that you spend over half an hour at the hones, but what you didn't state is what the razor needed.
Something tells me you didn't really made that assessment. (Please correct me if I'm wrong). If it means anything, I never hone on a razor without forming a good idea what I'm looking at.
Well. The razor was honed a full year ago by Olivia and until now it has only been stropped. No touch ups as far as I remember, nor any pasted stropping - I haven't got myself any pasted strop yet (though I'm planning to make a hard balsa strop as my good friend Torben shared some CrOx with me :) ). Indeed, I haven't really assessed the edge, although I had an idea (if it was worth anything :D ) of what needs to be done. Olivia told me she honed it with a layer of tape so I knew I needed to reset the bevel. So I started with a stroke on glass and began the job with thick slurry. Your detailed elaboration on how the bevel formation proceeds is truly a very valuable piece of information that I will remember and do try to make use of it. :)
Bart said:
Keep the narrow end of that hone pointing towards you. It will be easier.
Hmm. That's another story. [big]THIS[/big] is really baking my noodles! You asked for it! :D

Check out the following pictures. I hope they clearly show the idea, I borrowed the concept of lines showing contact / absence of contact with a stone from Urmas (hope you don't mind?). I also added an "intensity diagram" which is nothing more than a (rough) colour representation of how much honing certain areas get (the relation between the stone size and that of the blade is correct). There are also different strokes I was trying to help alleviate the problem.

[c]


[/c]

The point is that asymmetry of the stone causes different areas to receive different amount of honing, am I correct here? So I guess that rotating it now and then 180 deg is a must?

gotta run, I'll catch up with y'all later.
kind regards,
Matt
 

tat2Ralfy

Well-Known Member
If I may?

matis said:
So I started with a stroke on glass and began the job with thick slurry.

Watch the slurry is not too thick Matt, we are talking "Milk" not Cream and never Yoghurt.

Also I take it from your pictures that you are left handed? it matters not of course, however when it comes to symmetrical honing on a bout, I am sure you will benefit from keeping the longest side of the stone towards the razor, and try to think of your stone as being only as wide as the narrowest part, give your honing stroke a little roll and that way you should find it hones with greater balance.

Hope this helps my friend, keep us posted?

Best regards
Ralfson
(Dr)
 

Matt

Well-Known Member
tat2Ralfy said:
Also I take it from your pictures that you are left handed?
Not at all, it's all down on the upside, I drew it with the narrower end upwards and stayed somewhat fixed on it :)

tat2Ralfy said:
Watch the slurry is not too thick Matt, we are talking "Milk" not Cream and never Yoghurt.
Haha, that's the best explanation I've ever heard of proper slurry thickness, I think it should get its way to a beginner's guide! :thumbup:

Speaking of variance. I didn't write it earlier, but the former honing went quite well. I had a really odd Wapi that I recently bought, I went through a full Dilucot and bang, it worked! It lacked some final bit of keenness but it shaved really well. Yesterday I did two things. Firstly, after a short battle with myself I decided to remove some 0,05 mm of my lovely n[sup]o[/sup] 25, because it had some areas slightly below the surface - and moreover it was on the very narrow end, which rendered it roughly to effective 1 cm. Probably Bart didn't notice it at all, however it created some additional issues for me. Secondly - I further touched up the Wapi (again, on the [sup]o[/sup] 25) and it yielded my best HHT ever! Nearly complete 4 off the hone, stropping made it even nicer. It's not the end, though. :) This time, which is uncommon, the toe was left a little behind, so I figured I would try this vintage little one of mine. Bollocks, first stroke and I felt (heard as well) some tiny roughness, which ruthlessly damaged my oh-so-fresh dilucot edge, so I had to go back from delicate slurry on [sup]o[/sup] 25. Luckily I was able to tackle it well. It wass helluva late, though, so I don't know how it shaves yet! :D

kind regards,
Matt
 

Bart

Well-Known Member
Great drawing,

but -my psychiatrist will find this a great breakthrough :lol: -: you are over analyzing this. There. I've said it. Allow me to go lie down for a minute.:rolleyes:

In reality, the pressure on the small part of the hone is spread over a smaller part of the bevel. To an unknown extent, yet I'm sure it will be significant, that will influence the abrasion rate. Additionally, you are holding the razor at the tang. Per consequence, the heel will receive more pressure. Unless you have a finger on top of the razor, while doing halfstrokes. In that case, the placement of that finger will have a serious local influence as well. All these factors make it, in my opinion, completely unpredictable how the abrasion is distributed along the edge. Even if you were on a rectangular hone.

Luckily, there is one thing you might be overlooking, that safes our asses while honing. A razor's edge is a unity. You just can't divide it into a number of sections that don't influence each other. You just can't hone down one part without honing its neighboring parts as well. The kind of uneven edge shape you are doing math about, is something that can only develop very slowly, during many honing jobs. If you approach sharpening razors in a very idiosyncratic way, it probably will happen eventually. But if you care to look at the razor every once in a while, it won't be hard to steer things in the right direction. It's perfectly fine to do a number of extra strokes on the shoulder half only. It's even ok to make them with a straight motion, without going diagonal (X-stroke). It's only the general plan to do diagonal strokes. But you need to allow yourself to deviate, when that is called for.

Please look at this
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, first part shows bevel correction on a BBW. People tell me I'm doing crazy things in that video. First you'll see me doing full halfstrokes, next partial halfstrokes at the tip only (it was staying behind, judged by a quick TPT that isn't shown on the video). Then some halfstrokes with a finger placed strategically. The razor is shaving arm hair now, so I'm starting to do regular X-strokes on thinner slurry. A TPT (shown this time) reveals that I'm not getting where I should be. The middle part is fine, the tip and shoulder part are staying behind. So, back to halfstrokes, now on thin slurry. Tip only, first, then shoulder part with finger pressure.
My pall Robin once said he thought I was violating every rule in the book. :D Finally, when the shoulder part and tip fell into line, I finished with some careful X's on a very thin slurry. In the last part of the video, I'm waisting some CrO, which works, but has no significance for this post.

The bottom line is, don't turn this into mathematics. It's a craft.
I don't lap the Coticules in the Vault any flatter than they come from Ardennes, because the edges wouldn't be better. ;)

Yet, in spite of all my ramblings in your nice thread, it sound to me like you're really getting the hang of this. Your success on the n°25 confirms that. The rest will come with growing confidence.

:thumbup:
Bart.
 

Matt

Well-Known Member
Bart said:
The bottom line is, don't turn this into mathematics. It's a craft.
Yeah, I know, I'm the kind of a person that loves (needs) to know what's under the hood. Even if it sometimes means over analyzing. :D Although...

[box]"Over thinking, over analyzing
Separates the body from the mind(...)"
- Maynard James Keenan (of TOOL)[/box]
That reminds me photography a little. I mean traditional, darkroom, film and developer, all that messy stuff I used to do back when I was at school - when one has so much time... :) It also needed a bit of maths to determine proper development conditions and all, but of course it is all about shooting good pictures, not just properly developing your photos!

Bart said:
Yet, in spite of all my ramblings in your nice thread, it sound to me like you're really getting the hang of this. Your success on the n°25 confirms that. The rest will come with growing confidence.
Ramblings? Hello!!???

Ha. This in turn sounds like a go proverb (go is an ancient board game that I happen to play; "5 minutes to learn the rules, a lifetime to master") - "Strength comes from confidence, and confidence from strength" :thumbup:

Thank you all.

kind regards,
Matt
 

torbenbp

Well-Known Member
though I'm planning to make a hard balsa strop

Or you could pop over to Ray`s place and buy one...it`s almost embarresingly low priced and works great..Crox is included as well. Believe Sir Bart tested it at some time, just cant find it right now..

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Now ...this is another one of those videos that makes me wanna throw away all my razors and go back to a Gillette with 31 blades and internal power supply.. If ever I`ll be able to hone at half that speed I`ll feel like a million dollar :p great video Sir Bart.
regards
 
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