Polished edge retainsion

[db]

Are you trying to say a smooth polished edge performs better and lasts longer for slicing? If so I'll have to disagree with you.

 

[nozh2002]

Are you trying to say a smooth polished edge performs better and lasts longer for slicing? If so I'll have to disagree with you.

Can you give some example or something to support your position? I am not questining it, because I did not research slicing myself, I just like to learn something, not just the fact that you disargee, with all respect to your position.

I prepared two knives with rough and polished edges and found in a month of use that I prefer polished edge - it just cuts better, but I did not limit myself to slicing but just regular EDC things.

Thanks, Vassili.

 

[db]

Yup what and how you do your cutting makes a big difference in the type of edge you prefer. An exsample of slicing, pretty much any poly rope and I think you will easily see the difference between slicing with a different edge finish. If you want hard scientific test facts I'm not your guy.

 

[Jason B.]

Recently a friend of mine had me sharpen his kershaw leek. When he gave it to me it had a edge coarseness similar to what you would get with a DMT fine stone and was a little dulled from use. I rebeveled the edge and progressed through the grits finishing with a UF ceramic and stropping on .5 micron diamond paste. A week latter he questioned me on my sharpening technique because he said his knife seemed to be staying sharper longer. I am no expert but here is my opinion on the subject.

When you sharpen you create a burr on the edge that progressively gets smaller with each finner grit. If you stop the sharpening process around 1000 or 2000 grit you have a nice sharp edge but with a burr, may not be very noticable but its their. This burr is the first thing to break off/get worse when the blade is used, usually making the blade dull faster. When the edge is finished at a higher grit then stropped until the burr has been removed the blade can only dull as fast as the steel allows. Just my opinion but it seems to be true from experience.

 

[hardheart]

define polished and identify your sharpening equipment and technique. I don't think we should question the homogeneity of the blade steel until we know they're being treated equally in sharpening. heat treat is important, but it can be overridden by other factors.

 

[Vivi]

Yup what and how you do your cutting makes a big difference in the type of edge you prefer. An exsample of slicing, pretty much any poly rope and I think you will easily see the difference between slicing with a different edge finish. If you want hard scientific test facts I'm not your guy.

I'll go get some poly rope and try this. I've read a lot about low grit edges and their toothiness being good for slicing, but in my limited experience I can't recall having a low grit edge cut better than a high grit edge on anything. Do you think a DMT x Coarse and DMT Fine would make for a good comparison?

As far as edge retention goes, the sharper, more refined I've made my edges, the better they last. I'm not speaking strictly of grits here, but simply a good edge where I eliminate any detectable burr. Also reprofiling the edge has helped in this regard. I have knives that I took too thin and they chipped, and the areas with lots of chips still cut better than a lot of other knives I've used because it's so thin and requires such little pressure to cut.

 

[nozh2002]

Yup what and how you do your cutting makes a big difference in the type of edge you prefer. An exsample of slicing, pretty much any poly rope and I think you will easily see the difference between slicing with a different edge finish. If you want hard scientific test facts I'm not your guy.

Well, what you sad is perfectly scientific (scientific does not mean all thise whistles and blowers from Hollywood movies, but just following certain code), it is just better to give some more info. I did that cutting test as well:

http://www.youtube.com/watch?v=eCcbyJLAGAw

Which demonstrates saw effect. However, even it may have some advantages on certain cases, but for regular use to me it polished edge cuts better, easy and longer.

Thanks, Vassili.

 

[Jason B.]

unpolished sharpness

polished sharpness

Polished to me is a edge sharpened to 30,000 grit or more, I use DMTand spyderco ceramics then finishing with diamond strop paste, all free hand. I will not disagree that a polished edge does not always work best but for most things it seems to be better.

nozh2002, S90V can be sharpened by spyderco ceramics, I do it all the time.

 

[db]

I'll go get some poly rope and try this. I've read a lot about low grit edges and their toothiness being good for slicing, but in my limited experience I can't recall having a low grit edge cut better than a high grit edge on anything. Do you think a DMT x Coarse and DMT Fine would make for a good comparison?

I even consider a DMT fine a low grit finish. I’d suggest something that will polish the edge to ad to your example.

As far as edge retention goes, the sharper, more refined I've made my edges, the better they last. I'm not speaking strictly of grits here, but simply a good edge where I eliminate any detectable burr. Also reprofiling the edge has helped in this regard. I have knives that I took too thin and they chipped, and the areas with lots of chips still cut better than a lot of other knives I've used because it's so thin and requires such little pressure to cut.

Agree. Even with a low grit edge you need to sharpen it properly.

Well, what you sad is perfectly scientific (scientific does not mean all thise whistles and blowers from Hollywood movies, but just following certain code), it is just better to give some more info. I did that cutting test as well:

http://www.youtube.com/watch?v=eCcbyJLAGAw

Which demonstrates saw effect. However, even it may have some advantages on certain cases, but for regular use to me it polished edge cuts better, easy and longer.

Thanks, Vassili.

I think that is the best way to find out what type of edge works for you the best. However, what edge is best for you doesn't mean that is the best for everyone.

 

[Vivi]

I've been considering the Spyderco UF stone, might get it soon from the sales of some knives I posted in the exchange. The highest grit I have is 1200 aside from my loaded strop.

 

[nozh2002]

nozh2002, S90V can be sharpened by spyderco ceramics, I do it all the time.

Yes it can, but Fine does not make it sharper according to my statistic thred sharpness test. Medium does sharpen it, but not Fine.

Thanks, Vassili.

 

[nozh2002]

I think that is the best way to find out what type of edge works for you the best. However, what edge is best for you doesn't mean that is the best for everyone.

This is not about forcing somebody to use this or that it is about explaining why. So far I do not see anything like this, but just "my opinion is ... and I stay on it". This is fine and I respect it, however I like to see why? What is the basis for it is it solid or not? And so far I do not see any. Sorry. Just explain yourself, do not blame me in forcing everybody to accept my way, because it is not true - this is good move in political discussion, but this is not a case here (I hope). I just like to understand matter better.

Thanks, Vassili.

 

[Jason B.]

Yes it can, but Fine does not make it sharper according to my statistic thred sharpness test. Medium does sharpen it, but not Fine.

Thanks, Vassili.

Not trying to argue but you info is misleading. I use both the fine and ultra fine ceramics after a DMT ultra fine, if it didn't work then my knife would be dull and unpolished. Not sure about the fine but the UF is rated 9 of 10 on the Mohs hardness scale, harder than any S90V carbide.

 

[beckerhead]

My "scientific" results are from a 10" bowie in 1095. After putting a slick polished edge on it, I tried to slice free hanging rope to no avail. I slapped it back on my fine Norton India stone a few passes, and it sails right through the rope. For certain applications more tooth is nice to have. That said, with the exception of my kayaking blade, I much prefer a polished edge on my blades.

 

[db]

This is not about forcing somebody to use this or that it is about explaining why. So far I do not see anything like this, but just "my opinion is ... and I stay on it". This is fine and I respect it, however I like to see why? What is the basis for it is it solid or not? And so far I do not see any. Sorry.

Well, what you sad is perfectly scientific (scientific does not mean all thise whistles and blowers from Hollywood movies, but just following certain code), it is just better to give some more info. I did that cutting test as well:

http://www.youtube.com/watch?v=eCcbyJLAGAw

Which demonstrates saw effect. However, even it may have some advantages on certain cases,

Seems to me you see some of the advantages just fine. I’m not blaming you or accusing you of anything, I’m just answering your questions the best I can. If you really want to just argue I think you know where to find Cliff. So drop the victim routine.

Just explain yourself, do not blame me in forcing everybody to accept my way, because it is not true - this is good move in political discussion, but this is not a case here (I hope). I just like to understand matter better.

Thanks, Vassili.

 

[nozh2002]

Seems to me you see some of the advantages just fine. I’m not blaming you or accusing you of anything, I’m just answering your questions the best I can. If you really want to just argue I think you know where to find Cliff. So drop the victim routine.

Fine, this is also an informative answer.

Thanks, Vassili.

 

[nozh2002]

Not trying to argue but you info is misleading. I use both the fine and ultra fine ceramics after a DMT ultra fine, if it didn't work then my knife would be dull and unpolished. Not sure about the fine but the UF is rated 9 of 10 on the Mohs hardness scale, harder than any S90V carbide.

Edge was sharp after medium and Fine does polish sides - it was 9% of vanadium carbides and their size like 2 microns, so it does not affect polish look. But very edge on thread test shows no improvement. Again it require thread cutting test to see this.

Aluminum Oxide (ceramic) used by Spyderco 2400 on Vikers hardness scale, Vanadium Carbides - 2800.

Thanks, Vassili.

 

[Broos]

I commented based on my experience sharpening my various D2 knives - some will get sharper than others when taken to a fine (high) grit. I'm talking an increment of sharpness between shaving sharp and tree topping arm hair sharp. They all will get sharp, but they will all not get equally sharp. I have a couple that will get arm hair tree topping sharp at high grits, and have a couple others that just won't get there - they are still good cutters, but it seems a waste to me to take them beyond DMT 600 grit. They are born slicers for whatever reason. That different knives from different makers using the same steel will have some differences certainly didn't surprise me too much. And here I thought most folks prefer D2 with a good meat cutting type slicing edge.

If I was going to buy a knife with the express purpose of making it a polished edge push cutting monster, I would not buy it in standard D2. FFD2 on the other hand...

 

[nozh2002]

I commented based on my experience sharpening my various D2 knives - some will get sharper than others when taken to a fine (high) grit. I'm talking an increment of sharpness between shaving sharp and tree topping arm hair sharp. They all will get sharp, but they will all not get equally sharp. I have a couple that will get arm hair tree topping sharp at high grits, and have a couple others that just won't get there - they are still good cutters, but it seems a waste to me to take them beyond DMT 600 grit. They are born slicers for whatever reason. That different knives from different makers using the same steel will have some differences certainly didn't surprise me too much. And here I thought most folks prefer D2 with a good meat cutting type slicing edge.

If I was going to buy a knife with the express purpose of making it a polished edge push cutting monster, I would not buy it in standard D2. FFD2 on the other hand...

I always manage to sharpen any steel I have to hair whittling sharpness. BTW I was not too much impressed with FFD2 (I have) - I think they impress everybody with their initial sharpness, whittle hair NIB, but in terms of edge retention etc, there is no too much magic and CPM S30V left it behind on my tests.

Thanks, Vassili.

 

[Jason B.]

Maybe your thread cutting test doesen't work as well as you think.