Slicing and pushcutting TP

[Ankerson]

Hey Jim, can't get back to the PM's at this time my smart phone is not smart enough. I did notice a few of those things with the different blades I tried.

I think "tests" need to be explained though, too often you see great displays that are followed by abstract thought of the less informed. Kinda like when you hear "I chipped my blade" and its not really a chip.

Yes there is a lot more to it than just cutting. :thumbup:

 

[Obsessed with Edges]

I like your scale- I think it matches closely with my own personal standards, although now I'm going to have to add the push cut as a new personal goal. Way to go

The push-cutting sort of came about on it's own, as I've refined my technique & tried some new things. Didn't really set it as a goal. I really noticed it after I started using the sandpaper on leather, especially when taken up to/above 600 grit. Made me a real believer in the 'smooth shoulders' of a convex edge having a very real impact on ease of cutting. I noticed, one day while testing the draw-cutting (step #4 of my 'scale'), how smooth & easy the draw cut was. So it was almost automatic to just push the edge straight into the paper. It doesn't happen with every edge I've done, but it's nice to see it when it does.

Still workin' on trying to make that happen on TP, though. It's encouraging to see I'm not alone.

 

[rpttrsn]

Quote from KennyB
"I agree with you and see where you're coming from, but I don't think it really makes the TP test any less useful. I mean, I don't think hair splittings is a very good test methodology anymore either after some of my own recent results that would split hair but wouldn't shave. Then there's the fact that hair varies in thickness, hardness, color, and even the condition. Any time I went to pluck a hair out of my beard, I would have to make sure it was a thick black one with no cinks in it so that the testing was consistent. At least with toilet paper ( regardless of brand ) you're using a testing medium that is a lot more consistent."[/QUOTE]

KennyB,
Would you mind sending forum members, that would like a constant testing medium, some of you thick black hairs with no kinks from your beard?
This way we can compare hair to hair to find the sharpest edge.
This is a good discussion on sharpness and cutting ability. I have tried some soft two ply TP with poor results. (My wife's TP of choice) Yet the same knife will send hair flying off my arm and whittle hair without a problem. Would not the blade material, angle of the edge and Your Technique among a few other variables also play a part in your testing for the sharpest edge?
Find the best way for you to test each of the knives you sharpen that works best for you. Just my 0.02

 

[thombrogan]

I typically will push cut thread on a scale. I've seen lots of people use this, and in my "shop" (kitchen) its very consistent. However, my results do not mesh well with others and thus I cannot compare my results w/ thread cutting to anyone else.

What sort of thread do you use? What sort of scale? I sharpen in my creepy basement and could replicate some tests there.

 

[KennyB]

Quote from KennyB
"I agree with you and see where you're coming from, but I don't think it really makes the TP test any less useful. I mean, I don't think hair splittings is a very good test methodology anymore either after some of my own recent results that would split hair but wouldn't shave. Then there's the fact that hair varies in thickness, hardness, color, and even the condition. Any time I went to pluck a hair out of my beard, I would have to make sure it was a thick black one with no cinks in it so that the testing was consistent. At least with toilet paper ( regardless of brand ) you're using a testing medium that is a lot more consistent."

KennyB,
Would you mind sending forum members, that would like a constant testing medium, some of you thick black hairs with no kinks from your beard?
This way we can compare hair to hair to find the sharpest edge.
This is a good discussion on sharpness and cutting ability. I have tried some soft two ply TP with poor results. (My wife's TP of choice) Yet the same knife will send hair flying off my arm and whittle hair without a problem. Would not the blade material, angle of the edge and Your Technique among a few other variables also play a part in your testing for the sharpest edge?
Find the best way for you to test each of the knives you sharpen that works best for you. Just my 0.02[/QUOTE]

My sarcasm meter might be way off, but I don't think it's a good idea for two reasons 1) I'll run out! 2) I don't think they're a consistent test medium.

Even on the hairs that I can pick out by hand and judge them to be pretty much similar, the diameter varies by almost .0005". That's not a big variance, but I think when we're talking about the scale of a knife's edge apex it is. If I remember reading the Verohven studies correctly, most of the edge apexs were .0034", so I think a variation of that much would probably make a pretty big difference.

pwet,

That was my first thought too, but both sides cut just as effectively, and I even checked it out with 30X magnification and couldn't see anything, and spent some time stropping it, a couple of passes with extremely light pressure an an exaggerated angle to knock the burr off if I just couldn't see it, and it pretty much remains the same. It's one of the most confusing results that I've ever had, because by all of the tests I perform it should be able to shave just fine, yet it doesn't.

I think it just shows that whittling/splitting a hair can be done at a lower level than is usually thought unless it's done with the right technique. For example: If I hold a hair up between my thumb and index finger and allow it to stand on its own, and I run an edge along it and it takes a fillet out, I consider that truly hair whittling. However, if I can do the same thing, but start with the edge as my thumb as the backing to keep the hair from moving, I consider that whittling/splitting, but it's a lesser form since I still needed the hair to be kept stationary the slightest bit--a very sharp edge will just grab it. Then there's the "almost whittling" results I've seen where you kind of have to press into your thumb as the backbase a little before it will cut. All three of these levels will shave my hair, and I've seen them on anything from 1000 grit edges finished with CrO to factory edges that were probably finished at 325 grit and a buffing wheel.

To me it's more a matter of technique. If an edge isn't sharp enough to just grab on to a hair and slice it up, then the user might figure out a way to angle the hair to put more pressure on the edge, but that's the point at which the technique deviates and the results become somewhat meaningless.

At the end of the day, I use to use the hair splittign/whittling test as a, "Well, if it's that sharp, it will do anything I want it to including shave my face." I still think it works as a way to see if it's there without actually busting out the shaving cream, but it really doesn't tell me how sharp it is at all. I essentially work until I can shave my face, and call that good... How "sharp" that really is compared to anything else is something I don't think any of us an honestly determine because once we're talking about the scale where we're whittling hairs, then all the little variables like technique, edge geometry, environmental conditions, hair consistency, etc. have a magnitude more influence over the result of the test.

However, I still think they're pretty useful tests. If I can pull a hair out of my beard and whittle it, 90% of the time that means I could shave with it, and do pretty much anything else with it as well. In the end though, I can do the same thing by seeing how much the edge bites into my finger, and it would save me pulling a beard hair out... So I think a little bit of this testing is vanity, at least for myself personally.

 

[me2]

Aren't we starting to get a bit ridiculous with this level of sharpness? I mean, I sharpened my Para2 enough to pop hairs, but a couple of slices through cardboard and I completely lost that sharpness. I only see it as worth the effort with light cutting in the kitchen.

For God's sake man, you're on a sharpening forum on the interwebz. What kind of question is that?

Thom,

I just went to the supermarket and got a little pack of 5 spools of sewing thread, like for buttons and such. I have a small cooking scale that measures in oz. and grams, up to over a pound. I also use it for weighing sling stones, up to 18 oz. It's a direct spring scale, not digital.

Is the basement creepy before or after you start making the sharpening noises?

 

[Arakiel]

Sure, you guys can cut TP in half face-on, but I say you do the test edge-on. Now THAT would really be something. Personally, I'm going to try one of my blades on the edge of a regular piece of cartridge paper first before I attempt the TP edge challenge.
My guess is that I will go insane from the frustration before I split paper in two edgewise...or, given the fact that I am already insane for attempting this, perhaps I will go sane.

 

[Ankerson]

Sure, you guys can cut TP in half face-on, but I say you do the test edge-on. Now THAT would really be something. Personally, I'm going to try one of my blades on the edge of a regular piece of cartridge paper first before I attempt the TP edge challenge.
My guess is that I will go insane from the frustration before I split paper in two edgewise...or, given the fact that I am already insane for attempting this, perhaps I will go sane.

TP isn't stiff enough to do what you are saying, that's what makes it such a good test medium, it's somewhat strong, yet fragile enough to tear easy.

 

[Arakiel]

TP isn't stiff enough to do what you are saying, that's what makes it such a good test medium, it's somewhat strong, yet fragile enough to tear easy.

Apparently, you take this far more seriously than I do. My post was an attempt at humor, because it is funny as hell how serious you guys are about sharp. I mean, using TP for a relative sharpness test is like painting a clown nose on the Mona Lisa. It may be a good indicator, but it comes off as rediculous. It makes me laugh, so at least to me it's valuable for that.

 

[Ankerson]

Apparently, you take this far more seriously than I do. My post was an attempt at humor, because it is funny as hell how serious you guys are about sharp. I mean, using TP for a relative sharpness test is like painting a clown nose on the Mona Lisa. It may be a good indicator, but it comes off as rediculous. It makes me laugh, so at least to me it's valuable for that.

It's really about pushing limits as in how sharp can it get.

This is knowing that that level of sharpness won't last long when using the knife.

Cutting TP and making fuzzy sticks out of hair are just levels of sharpness like any other.

 

[Arakiel]

Gotcha.
Did you know that it's possible to sharpen a knife on a toilet lid? Take it off and use the unglazed edge underneath.
I can kill four birds with one stone. Shit-sharpen-test-shave.

 

[Ankerson]

Gotcha.
Did you know that it's possible to sharpen a knife on a toilet lid? Take it off and use the unglazed edge underneath.
I can kill four birds with one stone. Shit-sharpen-test-shave.

Anything that can scratch the blade and or is harder than the steel can be used to sharpen it.

The abrasives in cardboard let it be used to strop the edge.

 

[Arakiel]

TP isn't stiff enough to do what you are saying...

It isnt? Hmmm...I better re-read the TP wrapper....oh crap...my roll says "cash register refill cartridge". I guess that explains the occasional discomfort. I'll have to turn on the light in the supply closet at work from now on. My ass thanks you, Ankerson!