Hi,
I have developed a habit of taping spines when honing.
If a razor is once honed with tape, I suppose it has to be taped with every touchup you do on a coticule or pasted paddle?
I Just want to be sure.
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Hi,
I have developed a habit of taping spines when honing.
If a razor is once honed with tape, I suppose it has to be taped with every touchup you do on a coticule or pasted paddle?
I Just want to be sure.
Without putting words in people's mouths, I think Randy tapes, then polishes without tape. He is a honemeister.
I am currently NOT taping even on 1K - to preserve the original angle as much as I can. Not sure if this is correct... My thinking, however, is that if you really want to get the edge - it would make most sense to do no tape, then tape to polish (so that the edge has more exposure to the finishing material). Or - if you tape the spine - then double the tape for final touches (not remove it)
I am just throwing things out here and would not be embarrassed or surprised to hear I am wrong so let's hear what you think
Cheers
Ivo
For the record - despite what I think, lately I just use no tape whatsoever
I haven't tried it yet, but I think taping after honing will break off the edge since it is way to thin to handle the stresses. you'd get a double bevel, though I don't know how bad it would be. Perhaps it wouldn't matter.
My primary reason for taping the spine is that I don't want to damage other people's razors.
Going to the 1K (or even the 4K or 8) will leave a polished line on the side of the spine, which I don't like too much.
The problem with polising without tape (if you used it during honing) is that I think the edge does not touch the paddle or coticule at all, because of the difference in angle.
But that is just what I think, so that's why I asked. :hmmm:
Hm, I remember that I even used tape all the way to stropping on plain leather when I used tape on the spine for honing... Had good results, iirc.
I have tried tape to hone, then off for 20 laps or so on coticule - have to say this worked for me, too. Theoretically I agree that the edge would contact the hone in a different way - nevertheless, it does work, in my experience.
Very interesting if 'no tape hone / tape polish' or 'tape hone / double tape polish' approaches will break the edge - I don't think so, and was mostly thinking of the addition for the linen and stropping, which I'm thinking will be ok. I also think CrO2 should work fine... No idea about stones, though - such as Belgians, Eschers, etc.
Come to think about this I have a blade to de-chip and hone - maybe I can try this tonight and shave experience afterwards.
Cheers
Ivo
Hello all, I am taking a break from buliding my propane forge and all that stuff. Now to the topic....
I have not noticed any ill effect from leaving the tape on for the entire honing process including the pasted strop nor any when I remove the tape after the 8k or finishing stone (coticule, escher, 12K etc).
I have not tried adding additional tape yet. What that would do is create a micro-bevel. The technique is used by some woodworkers on their plane blades as an example. They have a honing guide made by Veritas that has the increased angle adjustment built in. If anyone is trying this then by all means let us know what you experience!:)
Bill Ellis was essentially doing this by varying the amount of pressure as he honed. In some ways we are already doing this when we start out using some pressure, 1-2 lbs, and then lightening up later but to s smaller degree.
Just my two cents,:)
There really is no reason to tape a spine when honing unless you are protecting a spine with a pattern like Damascus or have a lot of steel to remove as with a chip in the edge. The angle of the edge is consistent with the shape of the razor and all the tape does is create a different bevel angle. If you leave it on throughout the honing then you end up with a single edge unless you created a double bevel. So long as the edge is consistent, you should then be able to strop and shave.
Have fun.
Lynn
What would you use to tape the spine with? I am guessing something like electrical taping or something similar. This would increase the cutting angle, so on removing it you would reduce the angle, surely create a double bevel.
Excuse me for speaking out of turn - I am a total noob and have yet to even hone my first blade properly - but I have put some thought to this from a practical point of view.
If some pressure is used on the 1000 to set a bevel, the blade would also flex slightly - especially on a double hollow. In which case - and I know it sounds crazy - would you be better off NOT taping on the lower grits when you are applying some pressure, and taping on the higher grits so that the lack of flex in the blade has been taken into account?
Watching Alexs great honing video is what first sent me down this train of thought - he was applying some downward pressure at first, then as the edge came up he was relaxing. If the blade is flexing, even slightly, the angle of the bevel would be changing surely?
I dunno - like I say I am new to all of this, and have little experience to draw on.
I started out in the no-tape crowd, but now I pretty much tape every razor I hone. I use a single layer of electrical tape and find that it doesn't leave much residue on my Norton.
In theory, it makes sense that removing the tape late in the honing process (higher grits) would make for a double bevel, and that the very edge wouldn't get honed. I worried about this at first.
What I've found, though, is that the angle change is so slight that a few strokes on the Norton removes any double bevel that might exist.
I'll put tape on for work I'll be doing on 1K, 4K and 8K hones. I finish the edge on the 8K with the tape still on, then take it off to go to my pasted paddle strops. I hone razors for other guys, and most of them need to spend some time on the 1K. I prefer to let them wear out their razor's spine, not me. :)
For touchups, I don't bother taping the spine.
One thing I've noticed is that the taped blades handle differently than untaped ones--there's more friction. In some ways that's easier, and it's a little harder in others. I have to recalibrate my touch a little if I'm honing an untaped blade.
(Basically, honing for me has been a process of learning to listen to what Randy says. He'd answer a question for me, and I'd be like, "That doesn't sound right, I'll try it this way." My way would work OK, but eventually I'd figure out that Randy's way worked better. :shrug: I guess it goes to show that your experiences early on aren't definitive. It seems like the more razors I hone, the more I realize that the accepted wisdom is correct.)
Josh
I fall more in with Lynns line of thinking on the tape issue. I will not use tape very often, but I do at times do. I have a set of rules that I follow, based loosely on the amount of steel I plan on taking off. I will often tape on 1k hones or if I plan to do a lot of work on the 4K. If I am removing an "unnatural" nick in the blade I will tape the edge. I have decided in my own mind that this "extra" honing is not part of the edge's natural life cycle and is a correction.
You could make an equal argument that I should be honing without tape in that case to ensure the spine gets worn down appropriately.
If I'm just honing to improve the edge than I do not tape as I want the spine to wear evenly with the edge reduction.
I will always make an effort to remove the tape before finishing to ensure I reset the bevel correctly when done.
Is all of this needed? Got me. I too find Randy's advice the way to go, and with a few years of experience am now able to really coorelate what Lynn says too. It all starts to make more sense after a while.
I put a little more concern into the life of the spine/edge connection because I do not rotate razors the way many people do. I use one razor daily, everyday. I've used the same razor everyday for about 4 years now, with the occasional variation. But even with wicked spine reduction the edge still shaves great and the spine is still waaaaaaay wider than then edge!
taping the spine definitely changes the blade geometry of the manufacturer so dont tape the spine even if it needs to take of, dents!
The only reason to tape a spine is an estetical or psychological but then you make your personal cutting angle:nono:
(excuse me for my poor English)
Yannis, the change of geometry is so small that it doesn't really affect the razor's performance. It's only by a small part of a degree and various razors are ground with greater variations (of up to 5 degrees, maybe even more). 17 degrees is just a general guideline. 15 or 20 would still take on a good shaving edge as long as the steel is hard and fine-grained enough.
I find that new guys honing usually only tape because they wear down the spines so much trying to get an edge. It really is not necessary on most blades. It does work when you want to preserve a design or if you really intend to remove alot of metal as when you have a chipped edge. Electric tape is very sturdy.
Ilija, I don't know where you came up with your angles, but 17 is pretty steep.
Have fun.
Lynn
Nope, that's in the ballpark. Most razors I've measured have been between 15 and 19 degrees.Quote:
Originally Posted by adjustme69
First three I grabbed at random:
5/8 Clauss Barber's Special (mint):
0.65" by 0.18".
ATAN(0.18/0.65) = 15.5 degrees
6/8 Henckels Friodur (new, honed once):
0.75" by 0.24".
ATAN(0.24/0.75) = 17.74
6/8 Robeson Shuredge (NOS, honed once):
0.73" by 0.23"
ATAN(0.23/0.73) = 17.48
8/8 Wade & Butcher "Celebrated Razor for Barber's Use":
0.97" by 0.31"
ATAN(0.31/0.97) = 17.72
For computing the angle, only the distance from the edge to the wear mark on the spine matters. If you mistakenly measure from the edge to back of spine then most of these wind up in the 12-15 degree range.
I never had spine weardown issues. I use the tape just when cleaning up the edge. Once I finish on the 1k (for REALLY dull and/or damaged edges) and do a few strokes on the 4k, I take off the tape and do my regular honing without it. As for the angles... I remember that part from somewhere else, but Razor Central also confirms my statement:
Quote:
An edge should not chip off during adequate usage. Thin, weak and small-angled edges can handle delicate objects. The razor's 15-20* edge is an ideal compromise between sharpness and strength.
I do have one concern with using the tape, which is why I don't use it for final honing. It's a soft material and flexes a bit, so it doesn't yield sufficient precision for my honing skills.
Don't you use chrome oxide on a leather-covered bench hone for your final step? If so then the tape flexing doesn't matter since you're getting a lot more rounding from the bench hone anyway.Quote:
Originally Posted by FiReSTaRT
Quote:
Originally Posted by mparker762
?????? Can you elaborate on this? Why does a bench hone round?
What is this, a honemiester convention in this thread? :)
When using a bench hone, both the edge and the spine are on a flexible service. When using tape, only the spine is. I may be a bit unreasonable here, but we all have our little quirks. If Randy can hone up a blade all the way with tape on the spine, who am I to say it can't be done. I am just not comfortable with it.
What Ilija said. I also think that because the fin is also flexible it doesn't sink into the leather, but this simply means that the pastes backcut the fin so it weakens and eventually breaks off. My experience with traditional leather-covered paddles or bench hones is that after more than a dozen laps on the chrome oxide the edge gets duller, which I interpret to mean the original fin is collapsing. With a hardwood paddle this doesn't seem to happen - the blade gets a bit sharper and then it levels off, and repeated stropping on the paddle doesn't seem to make things any worse for a long time - it takes many hundreds of laps to overhone a razor at 50k grit :-)Quote:
Originally Posted by AFDavis11
This is one reason I've been a fan of hardwood paddles, though I've had a devil of a time dealing with warping. But the vellum-on-tile paddles I've made recently seem to work about as well but without the warping problem. Vellum is translucent rawhide made from calfskin or lambskin, and very thin and hard: about the same thickness as index card paper but a lot stiffer. Part of its preparation involves scraping it until it's evenly translucent throughout, so it's extremely flat as well. These vellum-on-tile paddles sound like hones when you're stropping (clack-swish-clack-swish) because the vellum is so thin and hard.
Edit: You can actually go edge-leading on these hones, though I haven't tried the resulting edge so it may not be an improvement (and may make them duller). But there's so little distortion that the blades don't catch at all when you run them edge-forward down the hone.
I can do two dozen without dulling. 20ish is the optimum number of passes when I finish on the leather bench hone. Sometimes I do a couple of shave-tests and then another 5-10 passes, before putting it into the rotation or shipping it out.
Wowza.....you'se guys is killin me......I'm ok with the 15 to 17 degree angles and these are basically based on the razor geometry itself in any case. Please keep measuring......lol. I have used the Chromium for years off a leather flatbed hone without any of the problems discussed here. I have also used it on paper over a glass flatbed and then with the edge into it vs. the stropping stroke and again no problem. The amount of strokes being advocated is excessive in my unlearned opinion, but as always, I bow to your expertise. Randy who.............
Lynn
Randy Tuttle for every time I mention a Randy in a honing-related discussion :nj
As for the number of strokes.. Well, many people do about 10 strokes on 1.0 before doing another 10 on a 0.50. I just do 20 on 0.50 instead and there are no adverse consequences.
Oh well.......I don't use the 1.0 either.......and I still don't do more than 10 strokes on the .5 but I can't be honing anywhere near as many as you. The part of all this is what causes all the confustion for new people. This stuff is not mystical but a process and nobody's word is gospel no matter how much they post. There are some basics that work most of the time and get people started and then it's getting to know all the different blades out there and then how the condition of the blades effect the honing.
You guys have fun.....I'm done with this one.
Lynn
Most of this is just experimenting around with the hones and pastes. When I leave the 15k Shapton I only give the razor about 5 laps on the chrome oxide paddle. But for touch-ups I don't usually want to haul out the Shapton while I'm standing there lathered up so I grab the paddle and I may well do 20 laps or so on the chrome oxide paddle, depending.
Unfortunately I've got pretty acidic skin: most jewelry starts dissolving on me within hours unless it's high-quality stainless or high-carat gold*, and this seem to be the big culprit for my razors as well. I can get two weeks** on an edge, whether I use it every day or use it once and put it away. But once I use and edge its days are numbered.
*Chrome-plated digital watches do better, but they corrode internally before my skin bubles the metal under the chrome. Stainless steel mechanical watches seem to survive because the jewel bearings insulate the important moving parts. So all my watches are stainless mechanicals.
**stainless razors are more like two months. I really like my Friodurs and Puma INOX razors.
Added a 8/8 W&B "Celebrated" to the angle measurements post.
Interesting, I've never heard of this sort of thing before. If you rinse, dry, and oil your blades after use is this still true?Quote:
Originally Posted by mparker762
In a PM to Lynn I handwaved off any error from the lack of right angles. I apologize, it's been a long time since I've done this for real and I didn't want to calculate chords on the curve the the honing flat makes as you sweep it around the fin of the blade, and I knew that my original calculation was understating the actual angle a bit. I smacked my head this morning when I realized I was being stupid, I simply had to correctly use the blade width measurement as the tangent and half the spine thickness as the sin and everything becomes simple again. The correct calculation is 2 x ASIN((spine thickness/2)/blade width), which gives you the correct right angle needed for the calculation. The asin calculation gives you the angle for one half of the blade. Corrected figures below...
The correct value is 2 * asin(0.09/0.75) = 15.9 degreesQuote:
Originally Posted by mparker762
The correct value is 2 * asin(0.12/0.75) = 18.4 degreesQuote:
Originally Posted by mparker762
The correct value is 2 * asin(0.115/0.73) = 18.1 degreesQuote:
Originally Posted by mparker762
The correct value is 2* asin(0.155/0.97) = 18.4 degreesQuote:
Originally Posted by mparker762
I apologise for the error.Quote:
Originally Posted by mparker762
Yea, ummmmmm thats just what I was thinking . . . either that or "holly cow this is getting complicated." :)
Are you saying you're dividing the Blade thickness by the height measured from where the shoulder hits the hone and then hitting your tangent button??
Lynn
The calculation needs right angles for correctness.
You can think of the blade as an isosceles triangle described by the edge and two honing flats, with the two sides of the blade as equal length, and the base of the triangle being the distance across the flats. If we divide this into two triangles, one for each half of the blade, then we get a right angle between the line down the center of the blade and the line between the two honing flats. We know the distance between the honing flats - that's the thickness of the blade, so half of that gives us the length of the short end of this right triangle. The length of the long side of the triangle is the width of the blade from edge to honing flat. Given the length of two sides of a right triangle we can calculate the third side (using the pythagorean rule) or any angle in that triangle. Let me see if I can draw an ASCII picture:
The width of the blade is W, the thickness at the spine is T. The angle that's easy to compute is "a", half the angle of the blade. Since we know W (the width of the blade along the side) and T (thickness of the blade), and the height of this half-blade triangle is half of that (T/2) we can calculate the angle "a" by the inverse sin function ASIN( (T/2) / W). But this only gives us half the angle of the edge, so we multiply that by 2 for the final answer.Code:
h /| (T)
t / | h
d / | i
i /a | c
(W) -----| k (T)
i \a | n
d \ | e
t \ | s
h \| s
The differences between the inverse tangent, inverse sin, and inverse cosine functions are that they calculate the angle "a" using different sides of the triangle. Inverse cosine would be used if you knew the blade width across the side of the blade and the blade width through the center of the blade, and inverse tangent would be used if you knew the blade thickness and the blade width through the center of the blade. In this case we know the thickness of the spine and the width along the side of the blade, so we need the inverse sin function. On a calculator these functions are represented by ASIN, ACOS, and ATAN, or sometimes as SIN-1, COS-1, and TAN-1 (where the "-1" is an exponent).
Edit: It just occurred to me that some of the confusion over the blade angle may be because I'm calculating the full blade angle, whereas knife guys generally talk about the half-angle, since this is what they set on their honing jig if they're using a Lansky, or eyeballing the angle between the knife and stone if they aren't. So if you want to compare these numbers to knife angles, don't multiply the ASIN value by 2....
Mparker,
Sorry, I'm confused:
I'm not completely sure what the definition of the angle of a blade is - is it 2a? From the way your ascii art is drawn, I guess it is.
Another question: if you rotate your picture 90 degrees clockwise, is that the equivalent of resting the blade on its back with the edge in the air? I'm confused about what you call the width of the blade - is it the horizontal distance from spine to point, or is it the hypotenuse of your picture?
If it's the hypotenuse, I get why you use sin. I'm just not sure the width is the hypotenuse - I'd have thought sqrt((t/2)^2 + w^2) should be the divisor in the arcsin calculation.
Or am I getting it all wrong?
James.
It seemed clear to me that what Michael called Width is the hypotenuse and that if you rotate 90 deg clockwise it would be like resting the blade on the spine. And that the blade (edge) angle is 2a.
Unfortunately I remember nothing about sinus, cosinus, etc. - what a shame
Cheers
Ivo
OK, I get it - it is the hypotenuse (sorry). Would you generally verify the assumption of equal angle (in case of uneven hone wear)? Or is this usually minor?Quote:
Originally Posted by izlat
SOHCAHTOA, Ivo!
James, is SOHCAHTOA an insult or something? I guess I deserve it, for not knowing basic things :o
I would think that uneven hone wear is indeed minor.
However, some razors, for example the TI PI hand forged LE, have weird geometry - different angles on both sides. Then the total edge angle would not be 2a; more like a+b.
Cheers
Ivo
The width along the side of the blade is the hypoteneuse of the triangle, whether it's standing on the spine or not (the hypoteneuse is the side opposite the right angle in a right triangle).
In the case of uneven hone wear or uneven grind (both sadly common) then you're on your own, my trig and geometry are too weak at this point.
Bruno, it's unnecessary to tape the spine. I know some have felt the spine would decrease in size over time but the angle geometry set by the spine and blade edge is an important one. Try this. Under magnification, examine some spines for wear. Tell us what you see.
Ivo - no, no, not an insult! Maybe it's just how we learned it in Australia, but SOHCAHTOA is an acronym for remembering the definitions of sin, cos and tan using a right-angled triangle.Quote:
Originally Posted by izlat
Sin - Opposite over Hypotenuse
Cos - Adjacent over Hypotenuse
Tan - Opposite over Adjacent
James.
It's important, but there's a wide range of acceptable angles. Unless your razor is already getting near 20 degrees, taping the spine is unlikely to change the geometry enough to matter.Quote:
Originally Posted by Howard
Now we only need conclusive research on the edge properties and feel in the 15-20 deg range :D
Might be a good weekend project for the scientifically inclined
Cheers
Ivo