Can you ever get a knife, too sharp?

[brasileiro]

When I'm done sharpening my knives always shave armhair with ease but I don't consider this uber sharp. I used to sharpen to hair splitting edges before and wouldn't carry a knife less sharp than that. Experience showed me that that hair splitting edge is gone in a few cuts and the edge settled down to a useful level for some time. I usually refined my edge down to around 1 micron or .5 micron finish too. Turned out that that kind of edge wasn't ideal for my uses.

My edges(and preferences) have evolved to a 600-800 grit finish that easily shaves armhair. I have found that this kind of edge(dependent on the steel, of course) suit my uses well.

Do you strop on any compound or just remove the burr with the 600-800 stones? Thanks.

 

[That_Knife_Guy]

Perhaps "the wrong kind of edge for the intended purpose" might be a better wording. An edge that is highly polished and very thin behind the edge might be wonderful for shaving, or push cutting through some vegetables. But it might be horrible for cutting rope.

I would agree you can put a super shallow edge on a knife but it will wear down so fast from everyday use you will have to sharpen it every other day. However your dad is right a steeper working edge on a knife is better for everyday use.

 

[singularity35]

Do you strop on any compound or just remove the burr with the 600-800 stones? Thanks.

If I'm in a hurry, I just raise the spine a bit do 2-3 very light strokes. If I have some time, I do the MB on fine ceramics. I seldom strop with fine compound anymore. I have some 28 grit diamond paste on a leather strop that I sometimes use on tool steels to finish.

 

[Uncle Timbo]

I would agree you can put a super shallow edge on a knife but it will wear down so fast from everyday use you will have to sharpen it every other day. However your dad is right a steeper working edge on a knife is better for everyday use.

I would do my heart good to know Dad is helping somebody from the grave. Big Harold.
They used to play a game where he working called, knife rolling. Some guy would walk up to you with a pocket knife in his hand, rolling it back and forth so you couldn't get a real good look at it. If you wanted to play, you pulled yours out and did the same thing. No commitment yet. Only when both said, let's trade. Then you found out what you were stuck with.
Crazy hillbillies. I think Dad kept a cheapie with him for rolling.

 

[brasileiro]

If I'm in a hurry, I just raise the spine a bit do 2-3 very light strokes. If I have some time, I do the MB on fine ceramics. I seldom strop with fine compound anymore. I have some 28 grit diamond paste on a leather strop that I sometimes use on tool steels to finish.

Thanks for reply.

 

[singularity35]

Anytime.

 

[Uncle Timbo]

I would agree you can put a super shallow edge on a knife but it will wear down so fast from everyday use you will have to sharpen it every other day. However your dad is right a steeper working edge on a knife is better for everyday use.

Thanks KnifeMan, I was almost feeling like it was me against BF.

 

[PoorUserName]

Well if you are just getting a shave and your head falls off i would says it was a little too sharp.

 

[Uncle Timbo]

Well if you are just getting a shave and your head falls off i would says it was a little too sharp.

Damn straight PUN.

 

[bucketstove]

Hi,

Given the proper edge angle on the right blade geometry for a particular use, I don't think you can over sharpen it. I think one can have an edge that is to thick or to thin. Depending if you want a chopper or a slicer.

Extreme example: putting a 10 degree per side on an ESEE 5.

Hi,
10 degrees per side on an ESEE 5 is an extreme example of? extreme chopper? extreme slicer?

Thanks KnifeMan, I was almost feeling like it was me against BF.

Hi,

Some people optimize to prevent gross damage (sharpened prybar or "survival")
and some people optimize for ease of cutting (important if you cut a lot)

Take a look at these two videos
Normark EKA 12C27 : optimal edge geometry for slicing hardwoods (norton economy fine edge) - CliffStamp
And this mind exploding material Extreme Regrind , ~6DPS no damage in 50 slices into pine, hardwood flooring and plywood the edge eventually gets damaged while cutting metal (steel food can)

 

[me2]

I would agree you can put a super shallow edge on a knife but it will wear down so fast from everyday use you will have to sharpen it every other day. However your dad is right a steeper working edge on a knife is better for everyday use.

Lower edge angles retain their edge longer, as long as they aren't so thin they buckle or collapse during use. That point will be different for everyone. 90% of my use can be done with an edge angle below 10 degrees per side. 99% can be done at 15dps or below. However, people do all sorts of things with their knives.

Just a few trends and clarifications related to this thread. Edge angle primarily controls strength and edge holding. Higher angles increase strength, lower angles increase edge holding.

Overall blade geometry controls cutting ability. This is things like primary grind angle, behind the edge thickness, and spine thickness.

Coarse grit edges can be extremely sharp by most standards, capable of whittling hair without stropping.

All steels will hold a working edge for a relatively long time, to the point I've used 440A/420J2 class steels to cut thousands of feet of cardboard and could still slice phone book paper.

 

[me2]

A bit more info l forgot. Behind the edge thickness is important for strength as well. If it's too low, the primary grind can ripple.

 

[Uncle Timbo]

That's a lot of cardboard.

 

[me2]

Yep. Ten kitchen trash bags full. I used a good bit for camp fires but recycled most of it. I'm sure l got some odd looks from the trash pickup company. $7 knife sharpened to a Spyderco medium grit ceramic finish at 12 dps with a 15 dps Sharpmaker microbevel.

Which brings up another point I forgot. Grit finish had a large influence on edge holding. You get longer slicing ability the coarser the finish. You get longer push cutting the finer. Which you use most determines how far you go in either direction. I tend to finish on my Norton Economy fine side or Spyderco medium grit ceramic finish. Either will tree top hair on my arm.

 

[Uncle Timbo]

Thanks me2 and everybody. As a lot of you already know, I'm a 62 y/o hillbilly from WV. We'll leave the redneck part out as it prolly depends on who you're talking to anyway.
Whoever says they know it all has a closed mind and that's no way to be. You all have helped me with that. Thank you.
You've helped me see things I was unaware of. Some were a tad over my head. I hope others have gleaned some info. To me, I think, the slickest thing in the world, is to get an edge, in a minimum amount of time, and be able to maintain that edge, in a minimum amount of time.
Lime someone here eluded to, sharpening is kind of Zenish, if you have the time.

 

[PoorUserName]

Is it possible to keep your blade sharp by just using a steel as continually removing metal is not the best way to treat your favourite knife.

 

[me2]

Yes it's possible, but it will only work for so long, and each time makes it a little shorter time until you need to steel again.

However a proper sharpening removes only 10 microns or so of blade width, so it's not really a big deal as long as your sharpening procedure is good and your not repairing damage.

Kootaga13, I agree completely now. I used to enjoy sharpening for its own sake, but now sharpening takes 2 to 5 minutes, so l don't even bother with touch ups once I've tuned a knife to the way I sharpen.