Unicot ?

[Joe Edson]

Been pouring over Bart's site trying to gain info on using my newly acquired coticules. I'm thinking the unicot method is the way to go. I do have a question though.

If you are worried about the spine, can you tape it during bevel setting and the first step in the unicot then add another layer for the second step? I know that you can do this for wedges as there is a sub section on his site that deals with those.

I'm asking more about full hollow's and the likes. Just really worried about messing up the spines as I learn to hone and want to be as careful as possible.

Thanks all

 

[azmark]

Yes you can. All of my worked spines and wedges that were honed with any hone I started with a layer of tape. So with the unicot you'll end up with a 2 layers when finishing. Just make sure you lay it straight and even on the second layer because the tape will be wet and I've learned that the second layer will come off in the middle of honing

 

[Joe Edson]

Yes you can. All of my worked spines and wedges that were honed with any hone I started with a layer of tape. So with the unicot you'll end up with a 2 layers when finishing. Just make sure you lay it straight and even on the second layer because the tape will be wet and I've learned that the second layer will come off in the middle of honing

Thanks for the answer!

I figured you could do this (and it is mentioned on the website that you have to do this for wedges), just wanted to make sure I wouldn't mess anything up with a full hollow.

I have a couple razors laying around that I may give this a go tonight

 

[Bart]

Indeed. You can protect the spine with one layer of tape and add a second for the final steps. On a typical 5/8 or 6/!8 razor one layer of electrical insulation tape (0.15mm thick), augments the bevel with approximately 0.7 degrees. Hence 2 layers will raise the bevel angle with about 1.5 degrees.
Most modern razors center around 16-17 degrees when honed without tape. 1.5 degrees more will still keep things below 20 degrees, the threshold at which I have started to notice a decline in shave comfort, notably a pulling sensation during the WTG pass. It shows up less ATG, because the edge make a more perpendicular cut, in relation with the shaft of the hair and the shaving angle. (during ATG, we typically use a lower shaving angle).

Anyway, you won't notice with 2 layers, unless the razor is already near the comfort threshold. Honesty dictates that not every one agrees with me on that threshold. I can only speak of personal experience.

As a final note: pasted stropping augments the bevel angle in similar amounts, due to cushion and slack in the pasted strop. I even suspect that Thiers Issard's "new forgings" bring this into account, in the way they are grind. They seem to be designed to respond perfect to TI's white paste on a paddle strop. I find that they shave best when I mimic the augmented angle with 2 layers of tape. But that's just me.

Kind regards and good luck,
Bart.

 

[BladeRunner001]

Indeed. You can protect the spine with one layer of tape and add a second for the final steps. On a typical 5/8 or 6/!8 razor one layer of electrical insulation tape (0.15mm thick), augments the bevel with approximately 0.7 degrees. Hence 2 layers will raise the bevel angle with about 1.5 degrees.
Most modern razors center around 16-17 degrees when honed without tape. 1.5 degrees more will still keep things below 20 degrees, the threshold at which I have started to notice a decline in shave comfort, notably a pulling sensation during the WTG pass. It shows up less ATG, because the edge make a more perpendicular cut, in relation with the shaft of the hair and the shaving angle. (during ATG, we typically use a lower shaving angle).

Anyway, you won't notice with 2 layers, unless the razor is already near the comfort threshold. Honesty dictates that not every one agrees with me on that threshold. I can only speak of personal experience.

As a final note: pasted stropping augments the bevel angle in similar amounts, due to cushion and slack in the pasted strop. I even suspect that Thiers Issard's "new forgings" bring this into account, in the way they are grind. They seem to be designed to respond perfect to TI's white paste on a paddle strop. I find that they shave best when I mimic the augmented angle with 2 layers of tape. But that's just me.

Kind regards and good luck,
Bart.

Bart,
This is great info ...thanks for sharing. I didn't know about this 20º angle. Are there any razors (in your experience) that one would need to worry about violating this 20º rule, so to speak?

 

[Joe Edson]

Indeed. You can protect the spine with one layer of tape and add a second for the final steps. On a typical 5/8 or 6/!8 razor one layer of electrical insulation tape (0.15mm thick), augments the bevel with approximately 0.7 degrees. Hence 2 layers will raise the bevel angle with about 1.5 degrees.
Most modern razors center around 16-17 degrees when honed without tape. 1.5 degrees more will still keep things below 20 degrees, the threshold at which I have started to notice a decline in shave comfort, notably a pulling sensation during the WTG pass. It shows up less ATG, because the edge make a more perpendicular cut, in relation with the shaft of the hair and the shaving angle. (during ATG, we typically use a lower shaving angle).

Anyway, you won't notice with 2 layers, unless the razor is already near the comfort threshold. Honesty dictates that not every one agrees with me on that threshold. I can only speak of personal experience.

As a final note: pasted stropping augments the bevel angle in similar amounts, due to cushion and slack in the pasted strop. I even suspect that Thiers Issard's "new forgings" bring this into account, in the way they are grind. They seem to be designed to respond perfect to TI's white paste on a paddle strop. I find that they shave best when I mimic the augmented angle with 2 layers of tape. But that's just me.

Kind regards and good luck,
Bart.

Thanks Bart! I was kind of hoping the expert would weigh in

I think I have a good candidate to try my coti for the first time tonight.

 

[Bart]

Bart,
This is great info ...thanks for sharing. I didn't know about this 20º angle. Are there any razors (in your experience) that one would need to worry about violating this 20º rule, so to speak?

Here's a short list of angles I have measured on a variety of razors all with different grinds and blade widths.
Jospeh Rodgers (wedge): 16,0
Thomas Ibbotson (wedge): 16,7
John Sellers (1/4hollow): 18,7
Frederick Reynolds (wedge): 18,3
NOS Friodur 7/8 SS (4/4 hollow): 17,8
Jopri n°860 8/8 (4/4 hollow): 17,6
S. Pearson&co 5/8 (3/4 hollow): 17,1
Double Arrow 6/8 (3/4 hollow): 17,2
SansSouci: 5/8 (3/4 hollow):18,7
Bartmann 504 7/8 (4/4 hollow):17,8
W.H. Morley & Sons: 16,3
TI Evidé Sonnant Extra 6/8 (4/4 hollow): 17,1

In the above list, the Sellers and the SansSouci would be near the threshold when honed with 2 layers. I never tried it on these, but I'm confident that it would still be alright, as long as the blades have impeccable edges. The wider the bevel angle, the sooner small imperfections along the very edge diminish the shaving performance.

To avoid confusion: I am talking about the enclosed angle between both bevel faces. On knife forums, they often use the half bevel angle, because it is the same as the honing angle.

Bart.

 

[BladeRunner001]

Here's a short list of angles I have measured on a variety of razors all with different grinds and blade widths.
Jospeh Rodgers (wedge): 16,0
Thomas Ibbotson (wedge): 16,7
John Sellers (1/4hollow): 18,7
Frederick Reynolds (wedge): 18,3
NOS Friodur 7/8 SS (4/4 hollow): 17,8
Jopri n°860 8/8 (4/4 hollow): 17,6
S. Pearson&co 5/8 (3/4 hollow): 17,1
Double Arrow 6/8 (3/4 hollow): 17,2
SansSouci: 5/8 (3/4 hollow):18,7
Bartmann 504 7/8 (4/4 hollow):17,8
W.H. Morley & Sons: 16,3
TI Evidé Sonnant Extra 6/8 (4/4 hollow): 17,1

In the above list, the Sellers and the SansSouci would be near the threshold when honed with 2 layers. I never tried it on these, but I'm confident that it would still be alright, as long as the blades have impeccable edges. The wider the bevel angle, the sooner small imperfections along the very edge diminish the shaving performance.

To avoid confusion: I am talking about the enclosed angle between both bevel faces. On knife forums, they often use the half bevel angle, because it is the same as the honing angle.

Bart.

Bart,
Thank you maestro...this is great. A couple of more questions:

1. The bevel angle that you are talking about is "the angle that the edge makes when the sides of the bevel come together", right? On a two tape scenario, this would be the secondary bevel? So, the the wider this becomes (more tapes), the sooner it will deteriorate the performance of the edge?

2. How do you measure these angles? The reason I ask is that as the bevel wears off, this angle will change over time (albeit very very slightly).

3. If your blade width is not constant throughout the blade, say you have 6/8 at toe and 13/16 at heel, this angle would also differ. How do you deal with this second scenario?

PS: I think this info needs to go in the Wiki...it is great and very useful from both a theoretical and practical standpoints.

 

[Bart]

1. The bevel angle that you are talking about is "the angle that the edge makes when the sides of the bevel come together", right? On a two tape scenario, this would be the secondary bevel? So, the the wider this becomes (more tapes), the sooner it will deteriorate the performance of the edge?

Affirmative on all questions. It seems that ages of razor making has established the optimal bevel angle for razors to center around 17 degrees. Significantly less will cause a weak edge that easily disintegrates from the stresses caused by honing and shaving. Significantly more will deliver an edge that has a hard time forcing its way in between hair cells. Remember that an edge is essentially nothing more than a wedge breaking in the matter it is trying to sever.

2. How do you measure these angles? The reason I ask is that as the bevel wears off, this angle will change over time (albeit very very slightly).

edge angle calculator
How to use, is explained inside.

3. If your blade width is not constant throughout the blade, say you have 6/8 at toe and 13/16 at heel, this angle would also differ. How do you deal with this second scenario?

You could use an average, but the point is that the razor might not shave well at any spot where it trespasses the 20 degree mark.

PS: I think this info needs to go in the Wiki...it is great and very useful from both a theoretical and practical standpoints.

Thanks. I never hone a wedge without doing the math. For modern (hollow ground) razors I hardly ever worry about the bevel angle, because they all allow 1 or 2 layers of tape. (I personally usually only use tape for honing wedges and TI's new forgings). Feel free to put the calculator in the Wiki.

Kind regards,
Bart.

 

[BladeRunner001]

Affirmative on all questions. It seems that ages of razor making has established the optimal bevel angle for razors to center around 17 degrees. Significantly less will cause a weak edge that easily disintegrates from the stresses caused by honing and shaving. Significantly more will deliver an edge that has a hard time forcing its way in between hair cells. Remember that an edge is essentially nothing more than a wedge breaking in the matter it is trying to sever.


edge angle calculator
How to use, is explained inside.


You could use an average, but the point is that the razor might not shave well at any spot where it trespasses the 20 degree mark.


Thanks. I never hone a wedge without doing the math. For modern (hollow ground) razors I hardly ever worry about the bevel angle, because they all allow 1 or 2 layers of tape. (I personally usually only use tape for honing wedges and TI's new forgings). Feel free to put the calculator in the Wiki.

Kind regards,
Bart.

That is excellent info and great calculator. Thank you Bart

 

[Joe Edson]

Well I just got honing my first ever straight using the unicot method. Started with a geneva razor I picked up on the bay in pretty good shape that came already shaving arm hairs (though not shave ready). Had to run it over glass twice for it to not shave anymore.

Wasn't worried about the spine, so just followed Bart's video to the T. Granted his video is 3 minutes and it probably took me 30-40 minutes, but I think I have success. Tomorrow will tell as I'll test shave it then. Very excited and it wasn't too hard.

My only real difficulty came with my slurry drying out as I honed I think cause I was so slow. Didn't really know how to deal with this, so I would occasionally add some water, but figured that might dilute the slurry, so I periodically raised slightly more slurry to compensate. Will have to give this a lot more practice to get the hang of it.

Hopefully tomorrow my shave is a success. Thanks again Bart for all the info and your great site!

 

[thanks]

Well I just got honing my first ever straight using the unicot method. Started with a geneva razor I picked up on the bay in pretty good shape that came already shaving arm hairs (though not shave ready). Had to run it over glass twice for it to not shave anymore.

Wasn't worried about the spine, so just followed Bart's video to the T. Granted his video is 3 minutes and it probably took me 30-40 minutes, but I think I have success. Tomorrow will tell as I'll test shave it then. Very excited and it wasn't too hard.

My only real difficulty came with my slurry drying out as I honed I think cause I was so slow. Didn't really know how to deal with this, so I would occasionally add some water, but figured that might dilute the slurry, so I periodically raised slightly more slurry to compensate. Will have to give this a lot more practice to get the hang of it.

Hopefully tomorrow my shave is a success. Thanks again Bart for all the info and your great site!

There are two things that helped me with my drying slurry problem. One of them was to stop honing under a ceiling fan , and the second was to stop the x-stroke prematurely so that I wasn't touching either edge of the hone vertically. That way I kept a good amount of the slurry on the stone where it belonged.

 

[Joe Edson]

There are two things that helped me with my drying slurry problem. One of them was to stop honing under a ceiling fan , and the second was to stop the x-stroke prematurely so that I wasn't touching either edge of the hone vertically. That way I kept a good amount of the slurry on the stone where it belonged.

You know I was honing directly under a ceiling fan last night and didn't even think about it! Will definitely have to correct that and I'll try a shorter X-stroke.

Thanks!

 

[SliceOfLife]

Well, I've historically hated the idea of taping spines. I consider it a lazy way out of getting a real edge. I won't even tape full wedges (instead spending literally hours beveling 50-100% of the blade) But with my new NOS with awesome spine work and a Beautiful W&B Masonic full wedge coming up on the honing block, this thread interests me, because if I do use tape (the alternative being to never hone them because they are too pretty to change) that one layer two layer Unicot will probably be the way I do it.

Oh and update your Sig, Joe. You don't need a G3 anymore, right?

 

[natchez]

I learned quite a bit about bevel angles from this thread- thanks guys!

 

[Joe Edson]

Well, I've historically hated the idea of taping spines. I consider it a lazy way out of getting a real edge. I won't even tape full wedges (instead spending literally hours beveling 50-100% of the blade) But with my new NOS with awesome spine work and a Beautiful W&B Masonic full wedge coming up on the honing block, this thread interests me, because if I do use tape (the alternative being to never hone them because they are too pretty to change) that one layer two layer Unicot will probably be the way I do it.

Oh and update your Sig, Joe. You don't need a G3 anymore, right?

Sig updated. Figured with my luck on the G3 and Semogue LE, then a TM 3" horsehide should be easy to come by right

On a side note (or is this more on topic?) Do you use the dilicot method with your coti. I think I would eventually like to be able to go that route.

 

[azmark]

Sig updated. Figured with my luck on the G3 and Semogue LE, then a TM 3" horsehide should be easy to come by right

On a side note (or is this more on topic?) Do you use the dilicot method with your coti. I think I would eventually like to be able to go that route.

Out of the 4 coti's I have only, only one of them gives me a consistent edge using the dilucot. It is also the one I bring out to use in the last step of the unicot method to use with just water. I get varied results with the dilucot but I need to spend more time getting to know each stone though.

 

[BladeRunner001]

Out of the 4 coti's I have only, only one of them gives me a consistent edge using the dilucot. It is also the one I bring out to use in the last step of the unicot method to use with just water. I get varied results with the dilucot but I need to spend more time getting to know each stone though.

Mark,
I have 3 Cotis as well:

1. Unknown quarry (8x3)
2. La petite blache (6x1.75-ish)
3. La grosse blanche (6x2-ish)

I have almost gotten #1 to reveal its secret and comfortably can get a a very nice edge off of it (both uni and dilucot methods)...I still have not gotten #2 or #3 to reveal their secrets to me yet...Many who have it say it is an awesome stone (but only once you get it working)

So, don't be disappointed...these natural stones are a little quirkier to work with because they each have their own little hidden personalities, which you need to reveal .

Do you know the quarries your 4 stones are from?

 

[Joe Edson]

I would have absolutely no idea where my 2 are from. They are both vintage ones bought off of eBay. One of them is a natural combo (though the BBW side is worthless as it is really chipped), the other one is definitely glued to a BBW though I'm pretty sure they no longer do this. Each of them showed PLENTY of use though as they required significant lapping to get flat.

Can't wait to learn the little intricacies of each of mine.

 

[Joe Edson]

Alright, just got done shaving with the razor from my first ever honing. I'm quite happy with the results and got a DFS, but not quite a BBS shave that I would get from one of my Ambrose honed razors. Noticed a little tugging with my ATG pass.

So......

Should I take this back to the Coti taping the spine and going to water? Do I need to restart the unicot process from the beginning? Maybe start at a taped spine with a light slurry then back to water?

I don't have CrOx at the moment, but would this help also. While I'm happy with the results, I would prefer something a little sharper. I definitely don't have any irritation or anything, but just want a slightly sharper blade.

Suggestions?