Folks,
What is the best way to establish or re-establish the bevel that gives you the best opportunity to get a super sharp edge?
jmsbcknr
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Folks,
What is the best way to establish or re-establish the bevel that gives you the best opportunity to get a super sharp edge?
jmsbcknr
I'm not sure I understand your question, but I use a heal leading stroke, not the x pattern and be very careful about using any pressure at this point. I usually build mine on 4-6K stones.
What's important is that you establish a CLEAN bevel. How you accomplish that is really irrelevant. If I've got one that needs lots of work, like an old, blunt, wedge or one that needs a complete bevel restoration due to chips, damage or extreme dullness, I'll use a circular motion doing one side at a time and keeping the razor on the hone. There's no need to baby an edge that needs a lot of work. That's like using a weedeater to mow your lawn.
A clean bevel, as I think of it, is one where the bevel is the same width on both sides of the blade and the scratch patterns are completely clean to the very edge of the blade on both sides and all the way up and down the edge. This can sometimes be hard to see with the naked eye, especially with fine grit hones. I usually use anywhere from 360 to 600 grit diamond hones to do this. That sure sounds like very, very coarse grit, but it works extremely well if you don't want to make a weekend project out of honing your razor - and the scratch patterns get straightened right up as you start going to finer grits one the bevel is established. As soon as the bevel is clean like that, it's been restored and more work on the large grit hones will only wear your razor unnecessarily.
Razors that have a farily clean bevel but aren't very sharp I start off with a 1200 grit hone, usually. It takes a little experience to determine just how much hone you'll need for each blade's condition. Some can be set straight away in little time with a 4000 grit. It all depends on their condition. Ideally, for minimum edge wear, you want to use the finest grit you can use to hone the razor without turning it into a honing marathon.
Most razors can be restored from butterknife dull to shaving sharp within about 20 minutes if you use right progression of hones. It's a waste of time to use one too fine and it's a waste of steel to use one that's too coarse.
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Robert,(Papabear)
I use almost the same proceedure as you do,and have had good sucess with it for many years.I rarely have to spend more than 20 minutes on a razor as you stated,unless they have some chunks out of the edge ,or geometry problems.I look at all of mine under a Stereo Microscope,(sometimes before and after)Usually only at 40X My microscope is a very good quality one with a long depth of field ,and I can also view the edges edge on(at about 70degrees,Ive been doing this a long time,and can pretty much predict how they will shave from the edge on view
Best Regards Gary
Okay, this is a really stupid questions. I think I know what you guys are talking about but I want to make sure.
What exactly is the bevel?
I assume that it is the actual part of the edge that is angled to cut. Like when you work on a 1000 you are trying to establish the bevel, maybe even 4000. When you work on the 4k and the 8k you are trying to polish the bevel that is established on the coarser grits.
You have it correct!:)
The one thing that will help you is to evaluate the edge before you start honing. Use either the thumbnail test or a handheld microscope. Then you can decide what grit you want to start honing with. Personally, I start with a 1000 if there are visible nicks or a 4000 if the nicks can only be seen under a 30X microscope. I use 1-2 lbs of pressure to start with and then lighten up as the nick goes away.
Hope this helps,:)
Quote:
Originally Posted by obsessis
Do you tape the spine when you use the coarser grits?Quote:
Originally Posted by PapaBull
No, I never tape the spine. That throws off the geometry of the razor, in my opinion. All areas that contact a hone end up being highly polished by the time they're shave-ready and the spine is no exception. I know some worry about excessive hone wear on the spine, but the spine is designed to wear down evenly, maintaining the geometry and once a razor is honed and the blade restored, it may never see a low-grit hone again.
I dont tape the spine,as this would defeat the purpose of what I'm trying to do by honing, first is to establish a bevel,Secondly, correct any errors in the razors geometry(equal widths on edge faces,and proper angles from edge face to spine)
Best Regards Gary
Thanks for the help. I have a norton 1000 and have been using it on the real dull razors to attempt to get a clean bevel from the tip to the back. I have been taping the spine, but will stop that in the future. The theory of keeping the entire razor in contact with the stone.
jmsbcknr
I had a recent e-mail correspondence with John Crowley on this recently. A while back I gave the formula for calculating the bevel angle of a razor. A typical angle is about 11 degrees, on a 5/8 with a 1/8" spine. If you tape the spine and take down the edge by 1/16" then hone the usual way to restore the angle as closely as possible, the angle may increas to 12 degrees.Quote:
Originally Posted by PapaBull
I like to tape when I use coarse grits because the metal comes off really fast, and it's not easy to control. If I don't take it off the spine, the taped spine will act as a guide for the edge (assuming I take it down that way) and I don't have to worry too much about the edge not staying parrallel with the spine. When I remove the tape the unchanged spine will act as a guide and the edge comes back into alignment. It's not so easy if you've removed a lot of metal from the spine unevenly.
I use this big 220 stone to re-establish bevel after heavy restoration, but some might think it's too coarse.
http://www.epicedge.com/pics/80025_1_n.jpg
available here:
http://www.epicedge.com/shopexd.asp?...68494419507306
Joe, I think where people get into trouble with uneven spine wear is when they try to hone out nicks and stuff by honing as usual except honing more on one part of the blade than another or applying more pressure there. When reshaping the blade due to previous poor maintenance and honing or chipped edges, sharpening out those nicks or upside-down "smiles" is a horrible waste of time and is a great way to get uneven hone wear on the spine.
If, on the other hand, the blade is shaped first by 90 degree honing (instead of 11 degree honing), the spine is as far away from the hone as it can possibly be and you have the opportunity to shape the blade as best suits your needs. Once that's done, I think it's important to put the razor on the hone as it was meant to be and then restore the bevel to the new edge geometry. A blade's spine is designed to wear along with the blade and if one wears without the other, the result is a greater deviation from the intended geometry every time it's honed as such.
But it's a pretty personal thing and I know some people prize the pristine look of an untouched spine. But a razor with a 6/8" blade shouldn't have a spine that was intended for an 8/8" razor and with enough honing, that's what we end up with if the spine is "protected" from the hone.
If you do it this way you'll end up with jus about the same angle as my way with a little more spine wear. I protect the spine getting down to the slightly larger angle the tape produces, then I go to essentially the same angle as you. The difference is if I was a little out of parallel after the 90 degree honing, the taped honinng will restore it.Quote:
Originally Posted by PapaBull
The spine is the only thing that holds the razor rigid. I'm thinking that spine wear and not edge wear will determine when the razor becomes useless.
I'm also trying to think of this another way. If you always hone the spine and edge at the same time (you don't do that either) you will be taking the same amount of material off of each. In order to keep the same angle you would need to take off the spine onl 20% of what you take off the blade width. So, you are changing the angle. What's more, if you took 1/16" off the edge and started with a 1/8" spine, it would be down to almost nothing. So, if you're taking a lot of material, like with a chip you have to do it with out taking down the spine or you'll have no spine.
I would usually start with the 1000. A minute or two of light circles on either side should do it without too much wear on the spine. Proceed then to some cirles on the 400 followed by an aggressive pyramid up to 25 on the 4k. That should do it. Doing the work without a 4k, I would do many more circles and tape the spine.
X
I know you understand this, but I want to make it clear for the readers. I would only use tape if had a chip or needed to remove a lot of material. That's also the only time I would use the 1K. Otherwise thw 4K should be good enough.Quote:
Originally Posted by xman
I tape the spine while I remove the nicks and restore the bevel. Then I remove the tape, but not before.
Quote:
Originally Posted by jmsbcknr
I used to use coarse grits to remove the nicks and restore the bevels. But... I noticed that when I would reach the 8000 the razor would occasionally develop microchips.
When I stopped using grits coarser than 4000 that problem almost disappeared. My speculation is that the coarser grits
created "fractures" in the steel.
Next, I doubt that the angle on a razor is really that sacred.
I have met men who use razors so badly worn that is amazing.
But they still use them every day! And frankly, most of us have so many razors that we will probably never see any appreciable wear on our razors. I tape my razors because I don't like to see the wear pattern on the shoulder.
OK, time for bed,:)
One can shave with a very poorly maintained razor. No doubt about it. I've had pocket knives I kept sharp enough to shave with. I never did shave with them, though, since I much prefer a really comfortable shave. The original bevel was put in place for a reason and not arbitrarily assigned. If a manufacturer thought 12 degrees or 13 degrees was just as good as 11 degrees, I imagine that's what they'd have built into their razors since the more obtuse bevels are more durable. But..... the nice thing about razors is that you can maintain them however you want and if you're happy with the shave; that's all that matters. It's good to have more than one perspective.
I've never met Randy, but I probably fall into the category he mentions. My two razors are almost assuredly badly worn/honed, but I shave with them anyway. When I shave, I never have the razor flat against my face. I have the spine tilted up to where it just feels right when I shave. So, in practice I would say that small angular differences do not make much difference.
p.s. now that I've discovered SRP with all this valueable knowledge, I plan to correct the badly worn/honed aspects.
Mike
I don't think so. What determines the bevel angle in a razor is the ratio between half the spine width and the size (width) of the blade. The reason is that the spine and edge both contact the stone. You can't escape it; it's physics. So, a manufacturer who makes a 5/8 with a fat spine will have a larger (shallower) bevel angle than one who makes a razor with a thin spine. It's the fatness of the spine that limits how sharp a bevel angle you can have.Quote:
Originally Posted by PapaBull
That doesn't happen with a knife, since the spine is off the stone when you're sharpening. You can choose your angle and trade off sharpness and durability of the edge.
Joe, let me rephrase that, since you, apparently didn't understand what I was saying.
Do you really believe that the ratio between spine width and length of blade, which determines the actual degree of angle of the blade was arrived at arbitrarily or just "happened"? While it's absolutely true that the width of the spine and length of blade (i.e. 5/8, 6/8, etc) determines the degree of the bevel, have you considered the possibility that the manufacturers made the spine the width needed for the proper bevel instead of just getting whatever angle they ended up with with whatever spine width happened to come off the grinder?
p.s... I wonder how many of the 5/8 razors with the "fat spine" are actually 5/8 razors instead of razors that were "fixed" by taping the spine and honing the crap out of it so the owner could try to pass the razor off as "mint".
That's an interesting observation. If your theory is right, I wonder why you don't see the fractures with the 4K, but you do with the 8K.Quote:
Originally Posted by randydance062449
Maybe the coarser grits just weaken the structure of the metal and you don't notice the effect until you try to put a real thin edge on the blade. The weakened metal just can't maintain the edge and portions collapse, forming micro-chips. You and I have noticed something similar with an oxidized edge.
I sure did consider it! That's why I checked a whole bunch of new or lightly honed razors for spine width. You can find quite a variation. Check it out. And after I measure the spine thickness and blade width I can calculate the bevel angle, which also has corresponding variation.Quote:
Originally Posted by PapaBull
There may be a minimum spine thickness that will insure blade integrity over the life of the blade, but after that it's just a function of the ornamental design (spine thickness needed to get a desired effect).
I guess we just disagree. I don't think the spine thickness is an arbitrary width based on the designer's/grinder's ornamental preferences. Spine thicknesses were designed to provide the proper bevel, in my opinion. And I prefer to keep that bevel intact by honing blade and spine together whenever possible. They're designed to wear at the same rate. A razor honed from a 6/8 to a 5/8 over it's life will also have had the spine honed from a width appropriate for a 6/8 to a width appropriate for a 5/8. Pretty ingenious, if you ask me, so I don't try to outsmart it just so that I can keep my razors looking like they've never been honed. I figure that's a bit like rolling back the speedometer on a car, anyway. It looks good, but it won't make the car won't perform like a new car - and a razor that's had it's "spine protected" won't perform as it was designed to perform, either, with the angle getting more and more obtuse with each honing.... but that's just my opinion. Who knows, huh?Quote:
Originally Posted by Joe Lerch
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The spine to blade width ratio is 3.5. It is stated in the german book from the 30' called Das Rasiermesser. That's why the spine gets thicker when you progress in razor's size...
Nenad
I think you guys ought to examine some of your razors (I did). You might be surprized art the variation in spine width in a given size of razor. Of course I'm talking about razors that haven't been honed significantly.
I think we've been trhough this once before. The reference you sited related to a specific type of razor, not in general. The 3.5 ratio will give you an angle of over 16 degrees, which is more than what I've found in any razor.Quote:
Originally Posted by superfly
If you want to know the angle of any of your razors, take the ratio between half the spine thickness and the razor width. That's the tangent of half the bevel angle. Look up the angle in a table or use the "arctan" (also tan to the -1 power) on a calculater. A 1/7 ratio gives you 8.1 degrees and you bevel angle is 16.2 degrees. Do you have that on any of your new or lightly honed razors? A 5/8 razor with a 1/8 spine (kind of typical) has 11.4 degrees.
The spine gets thicker when you progress in razor size because you need the heavier spine to support the razor.
If you want some examples, I'll post spine widths for different razors in my collection. Try it with yours.
:shrug: Found it on RazorCentral, here's the link...Quote:
Originally Posted by Joe Lerch
http://www.en.nassrasur.com/razorcentral/archraz2.html
I think it is ment for all razors in general. Anyways, I don't care, as long as my razor is sharp enough...
For all newbies, check Artur Bohn's razor central, it has some great info on razors and shaving...
http://www.en.nassrasur.com/razorcentral/index.html
Nenad
I'm afraid that's an incorrect conclusion. The spine gets thicker with the bigger blades because it's necessary to maintain edge geometry. It doesn't take 1/2" of steel spine to support a paper-thin razor blade, Joe. Machetes take a lot more of a beating than razors, but only need a spine of approximately 1/8" to "support" the work that blade does. The spine width has been built into razors specifically to precisely maintain the edge geometry, not for looks.Quote:
Originally Posted by Joe Lerch
Framebacks, for example, have very thin blades all the way through and the geometry was maintained by setting a built-in blade guide for honing; the frame back.
The earliest razors had to be honed without a honing guide and were built pretty much like knives. Then came the wedge grinds. Then the frameback design, then the hollow grind. From the wedge to the present extra-extra-hollow ground razors, the spine's width was always calculated to give the razor the best edge geometry for it's design when laid flat on the hone.
I simply can't go along with the notion that the spine gives us a proper angle by pure coincidence just because a big, thick spine was needed to support a thin, fine blade that was meant only to push cut hair while big bowie knives designed to hack on trees, firewood and to be used in battle require less spine than that.
Nice post guys and very interesting. I have one question if I can explain it right. On some razors the edges width is very small sometimes 1/64 to 1/32 of and inch wide. The spine's width, the width that actually touches the hone, can be wider than that of the edge. Will this cause the spine to wear away slower than the edge? Also as the spine wears away this width can increase which may decrease wear even more because of the extra metal in relation to the width of the metal on the edge. This may change the angle of honing a very little bit and may not make any difference at all. What do you think?
The "rails" that form as the blade is honed are often wider than the honed edge of the blade, but that really has no bearing on them wearing evenly as they're honed. Think of a razor as a triangle. A true wedge actually IS a triangle. A hollow grind razor is a wedge with the middle ground out. It still follows geometry like a triangle and hones evenly as a triangle, provided the pressure is even during the honing process. Whether the "rail" is wide or narrow, the edge and spine should wear quite evenly, maintaining the gemetry.
Sorry to stick my newbie nose in here. Hope this isn't considered rude. I've been following this thread with great interest as I want to try and restore a proper bevel on a razor. It seems then I should be concerned about not just honing out nicks but also the spine thickness to blade width ratio in case the razor was unevenly honed (spine taped or not taped)? Is there some magic angle for straights, and how critical is it to getting a great shaving edge? :confused:Quote:
Originally Posted by PapaBull
Mike
As I told you that's a particular type of full hollow with a belly. It's not general.Quote:
Originally Posted by superfly
don't disagree with this. I think we're both right to an extent. If I showed you substantial variation in spine width for razors of the same size, what would you say. You can start by comparing a Bergischer Lowe to a sleek 5/8 razor with a 1/8 spine.Quote:
Originally Posted by PapaBull
Ok, compare a frameback to a sleek 5/8. Do you deny that the spine has to be heavier because of the more delicate blade?Quote:
Framebacks, for example, have very thin blades all the way through and the geometry was maintained by setting a built-in blade guide for honing; the frame back.
I don't know how far you want to go back, but the earliest ones of interest to me are the true wedges. There you're honing the entire side. Is that a guide?Quote:
The earliest razors had to be honed without a honing guide and were built pretty much like knives. Then came the wedge grinds. Then the frameback design, then the hollow grind. From the wedge to the present extra-extra-hollow ground razors, the spine's width was always calculated to give the razor the best edge geometry for it's design when laid flat on the hone.
Any machete I've ever seen has a lot heavier blade than the thin part of a razor. You can move the front half with your fingers. That offers no structural intergrity and requires a relatively hefty spine. Once you have the minimum requirement you have the sharpest edge. If you want to make a Bergischer Lowe you have a thicker spine and a substantially different angle. I disagree with the idea that there's a precise angle that a razor is intended to have. If you're interpreting my statement to mean any more than a substantial variation in angle can result from design considerations, you're reading too much into it.Quote:
I simply can't go along with the notion that the spine gives us a proper angle by pure coincidence just because a big, thick spine was needed to support a thin, fine blade that was meant only to push cut hair while big bowie knives designed to hack on trees, firewood and to be used in battle require less spine than that
The bottom line is there's no precise angle. You can prove this to yourself by measuring the spines of different design razors of the same size. Like I said, I've been through the exercise.
Nenand gave a rule that results in a razor with more than a 16 degree angle. I've seen it stated as 11-15 degrees. That's quite a range. I think you'll find that most of you conventional razors are around 11 degrees.
The thickness of the rails can be greater. If you think about it, theoretically, you remove the same thickness of metal from the edge and the spine, if your pressure is equal, so the angle should be the same when you hone normally.Quote:
Originally Posted by str8razor
It seems to me that Robert and I do the same thing if he hones the blade perpendicular and I tape. In both cases, the spine is not honed as you bring the edge to the correct width. When he drops down and resores the edge, that the first time he's removing material from the spine. It seems to me that he's taking a lot less than if he honed down the edge all the way with the spine in contact with the stone.
Robert would say yes, but I can disprove this easily by showing a group of razors of the same size with all different angles. Nenand would say yes, but I don't think it would be easy to find a rozor with a bevel angle in excess of 16 degrees.Quote:
Originally Posted by eagle
If you agreed with them, you would have to know what angle the manufacrurer originally designe into the razor. That could be imposiible with a razor that has significant honing. I would say make it easy on yourself. Hone the edge and rails nice and evenly. Measure the thickness of the spine and the width of the blade. Try for a ratio of 5:1. That will give you 12 degrees for the bevel angle. The greater the angle, the less sharp the edge, but the stronger.
There is an ideal angle, at least as designed by the manufacturer. Different razors can have different bevels. Some shave better than others. Some maintain an edge better than others. There are lots of variables. The best manufacturers put a lot of thought into their designs and the designs got better and better, for the most part, as they got more experienced with their craft and new designs were developed and tested. There will be variations from one razor and manufacturer to another in the degree of angle, but it's not arbitrary and ideally, if it's a high quality razor, I'd recommend trying to maintain the design geometry as intended as best you can. But.... that's just my take on it. Anyone that feels their razor would be better with a different honing angle can go ahead and do that, too. If it's not my razor and it's not my face and it's not my shave, I won't insist that there's only one way to do things. To each their own. I shave with a straight razor every day and have for a long, long time now and I know what I like and what works for me and that's all I can vouch for.
John D. Verhoeven, Emeritus Professor on the Department of Materials Science and Engineering at Iowa State University discuss the same thing in his .pdf document titled: Experiments on knife sharpening.
you can find it here:
http://mse.iastate.edu/files/verhoeven/KnifeShExps.pdf
He, among other things, discuss Straight razor and commercial DE (Gillette) blade. In the both, he measures the very same angle of 17 degrees, and states a table of given angles for various tools, where he says the ideal angle for razors is 15-19 degrees. "The blade is a stainless steel blade manufactured by the Solingen Co in Germany. As shown by the end view of the blade in Fig. 8, the blade has the hollow ground surface of straight razors, which ensures that stropping on the razor strop will maintain the surface at the edge on a constant abrasion angle with the strop surface. As shown in the figure the Solingen blade will automatically sharpen to give a 2β angle at the edge of 17o. It is interesting that both razor blades have an edge angle, 2β, of 17o."