coarse edge vs fine polished edge

i have probably sharpened enough knives over the years to fill a pickup truck bed and then some. i got into sharpening knives back in 1973 when i was 13.

i have put both high polished and coarse edges on knives and i have found out through feedback that the coarse edge is all you need and can cut just as good if not better than a high polished edge.

i put a super fine edge on a knife for a buddy (with a new stone another buddy gave me) that looked like a mirror. he cut a lot of cardboard and plastic straps where he worked at. a few days later he brought the knife back to me and asked wtf kind of edge i put on it. he said the edge crapped out soon after cutting some cardboard like he does every day. he said the edge i put on before lasted for over a month. i resharpened his knife like i did before. he said that edge held up great.

here is a good example. i sharpened a regulator for mrcweiler and the grit used was 120. it was so sharp that he told me he was afraid to play with it. here is the link to his post he made on the forum. http://www.scrapyardknives.com/ubbthread...page=0&vc=1

a high polished edge might look nice but when it comes down to it, that kind of edge will fail faster. i use paper wheels and the slotted polishing wheel will put a polish on the edge but the coarse grit used to work up the burr will result in a toothy polished edge with bite. a fine highly polished edge done on fine grit (1/2 micron) will be similar to a wire thin edge and will roll or fail when you really need it the most.

i have read where others have tested this out and agree with my findings.

I prefer a coarse edge on my working knives as well.

I just use the fine rods on my Sharpmaker. I have a Spyderco Tenacious that I recently did an edge retention test on it. At the beginning of the test I could push cut through a receipt. I then made 15 various kinds of cuts on a Monster energy drink can. At the end I could still cut through the receipt in very fine slices but not push cut as well. I think the Flat grind on the Tenacious results in a slighty toothy edge because if I run my finger nail on the bevel about the edge of the knife I can feel small ridges on it.

i never go over 400 grit when i put a convex edge on a knife. when i sharpen the bowie i made i think i'm going to try a coarser belt (80 grit maybe) and go above the burr with a 400 grit belt to smooth above the edge before removing the burr and polishing the edge. that will leave a coarse toothy edge and match the satin finish i'll have on it.

most of the busse knives i get in for edge convexing still have the coarse grit factory v edge. they were shaving sharp and would only need a good stropping on medium grit white rouge to improve the edge.

Well I cant wait to send in my Rodent Solution to yah because it sounds like it will come back amazing!

I am sure you will be very pleased when you get it back. Just be careful when handling it. I didn't realize I was cut until I saw the blood.

Now THAT is sharp!

I ususally use the paper wheels, and they polish it up nicely.

Never noticed a huge difference in edge retention between coarse and polished.

I have done the mirror polished edge and don't like it. Like they said, seems to "Go away" to quickly. I like a bit courser edge that has some "Grab" to it. I will usually go on a smiths course diamond hone, then a Spyderco medium (brown) ceramic and then SOMETIMES a few strokes on a fine DMT folding hone.

I have about decided that polished edges are nice for kitchen knives, and to look at. Actually use, especially for stuff like I do I need more bite. In fact, I might be working on a few edges tomorrow.

I agree. I prefer a smooth polished edge on blades I plan to do fine work with or fileting a fish, but for a hard use knife, nothing beats a slightly coarse edge. Think of it as micro serrations. Try cutting a thick rope with a shiny razor edge and a sharp coarse edge. You will notice the difference immediately.

120 grit is what comes on the paper grit wheel. you can get different grit powders at detroit abrasives. if you have a belt sander and the wheels, try working up a burr with 80 grit (light pressure) and finish it off on the slotted wheel.

i prefer a coarse edge especially on my SOD. im scared having a thin, polished razor sharp edge would just roll with the first chop.

i find that a coarser edge is also way better in the kitchen. the other night i was trying to slice up some habaneros and the fine polished edge on my Wiener <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> would just slide right off and could not bite into the smooth surface of the chili. so i did a few swipes on a medium ceramic rod, it was still hair poppin sharp and you could feel the edge had a bite. my Wiener sliced the crap out of the habaneros after that.

I don't know Tony, the roughing up of my Wiener doesn't sound very appealing

lol, trust me… the rougher the better.

I just guess some folks like it rough! <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

i had a knife sent to me for a convexed edge. the guy tested my knife against a knife that someone else sharpened to a wire thin high polished edge (that probably took the person 2 days to do). that knife did poorly at cutting where mine kept cutting. he made a post in my paper wheel thread over on bf. post 710 and he goes by stevenkelby.

Nevermind the rough, but then using it on habaneros after.. Your Wiener sure gets some action.. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

<img src="/ubbthreads/images/graemlins/eek.gif" alt="" />Habaneros? <img src="/ubbthreads/images/graemlins/eek.gif" alt="" /> You're sure tough on your Wiener! <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" /> <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />

tonester, have you ever cut yourself on the knife and told someone you cut yourself on your wiener <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />? have you ever ran into a girl that was into knives and asked her if she would like to see your wiener <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />?

Richard, I believe similar questions were asked shortly after Dan posted pics of HIS wiener! <img src="/ubbthreads/images/graemlins/eek.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

i see a new thread title for the paper wheel thread <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> "how to sharpen your wiener in under 1 minute":D.

I usually don't go beyond 400 or 600 grit when I sharpen but I do use a leather strop and some stropping compound at times. I think edge geometry has a lot to do with edge retention and I suppose it is possible that by going for the mirror polished edge, at a microscopic level, you are also changing the edge geometry, thinning the very edge. So, it does make sense that the mirror polished edge might be the weaker of the two...but it also seems that initially, the mirror polished edge would be sharper (due to its thinner edge).

I agree. Coarse edges can also be shockingly sharp when done right. I had posted pictures of my Regulator before:

[img]http://www.flickr.com/photos/59741147@N02/5627840654/in/photostream/lightbox/[/img]

http://www.flickr.com/photos/59741147@N02/5627840654/in/photostream/lightbox/

[img]http://www.flickr.com/photos/59741147@N02/5627840286/in/photostream/lightbox/[/img]

http://www.flickr.com/photos/59741147@N02/5627840286/in/photostream/lightbox/

This is a 120 grit edge, polished up with a slotted wheel. You may be able to see some microserrations in the second picture.

I had some friends come over yesterday. They glanced at the knife and were intrigued by the shimmering grind pattern on the edge. I showed them how sharp it was with clean push cuts on an old thin paper receipt that was lying around. Jaws dropped in awe.

They didn't know that I had cut up several cardboard boxes and an old carpet earlier in the day with that blade. I want to see how long the edge lasts before requiring a touch up.

I am just curious though. How sharp does a knife really have to be? Like I don't mean this in a derogitory way. I mean what is an adequate sharpness to you guys? To me when I can push cut a receipt I consider that quite sharp.

Oh young Grasshopper, sharpness is a relative term. Each person has to determine for themselves what "Sharp" is TO THEM. My sharp may not be your sharp and vice versa. IF YOU are satisfied with the edge and consider it sharp, who am I or anyone else to say you are wrong. Come to terms with your definition of sharpness and be satisfied with it until you decide to change YOUR definition of what sharpness is. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Do not worry young friend, with age comes wisdom, but mostly forgetfulness. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

I am not saying I wouldn't mind a sharper knife but I dont really have a ton of experience yet. I have only been collecting knives for maybe a year. I should try out some paper wheels. Richard doesn't even live that far from me either.

Take my advise or not, it may not be the ideal situation for you, but I think like this. Get a diamond hone of some sort. I bought a 6 in smiths course (yellow) hone for $22.00. Practice on that. Then If you want a little more refined edge, get a fine stone (usually red). Learn to use them. That way if you are "out and about" you will have the skills necessary to put a new edge on your blade or blades. You MIGHT want to try the DMT folding two sided hones. One side is course grit about 300 and the other fine, about 600. The reason I said smiths hones is they are usually cheaper than DMT and I can't really tell a difference.

As I said, this is just my two cents and something for you to think about, nothing more.

Oh and one more thing, for real portability check out the EZE-lap model M diamond rod. It is the choice of a lot of "experts". I have one and like it, Diamond coated steel rod in a brass holder.

For me, what I consider sharp a lot of times others I KNOW would not. But I have found out over the years that the edges I put on my blades work just fine for me.

Different strokes for different folks! <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

I would like to learn freehand sharpening but I wasn't having much good luck with it. I was dulling my knives pretty badly. I use the Sharpmaker at the moment and I love it.

I can sharpen freeman better now than I used to. Still use the Sharpmaker a lot too. Plus I have used the sandpaper and mouse pad method as well. Just experiment and you'll find what works for you.

YUP, what Todd said.

Oh and Tom too! <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Y'all getting hit pretty hard by rain Tom? It's started here again.

Yah the only problem with the sharpmaker is I can sharpen convex edges with it. So the paper wheels would allow me to sharpen Swamp Rat knives or the Scrapyard knives that come with one. Rather than sending each knife out to have the edge reprofiled.

Not a HARD rain, but plenty wet and cool! <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />

steeley, if you come down i can teach you my method of freehand sharpening and how to use the wheels. keep in mind that the grit wheel will only sharpen a v edge knife but you can maintain an existing edge or strop the burr off of a freshly formed convex edge.

I like the DMT diamonds better than the Smiths but use both. In fact I took my Smiths yellow and orange diamond sharpeners to a buddys gun store and left them there so me and Stevo, a member here, can work on blades when time allows. I have a DMT folding that is blue (coarse) and red (fine) and a green that is extra fine, and a bigger red DMT bench. I also have various stones, but I am not that good with them but I think that is due to quality because I have a couple that are very old that were my Papa's and they do a better job. As to the convex, at the moment I use paper and mouse pad. I do follow up with stropping on an old barber strop. Just what I do.

If I can shave my arm hairs, its sharp enough. My arm hair is fairly fine, so its much harder to shave mine than most guys. That's my static test.

That used to me my litmus test, but I don't even worry about going that far most of the time anymore. I still get a good fairly long lasting edge though. Hey, it works for me and that's what counts.

It'll grab my thumb nail and it will slice hand held paper.

Slicing paper is another test I use. Sometimes I'm all out of arm hair.

Any more I will use the course smiths diamond hone, then go to the medium Spyderco ceramic and then finish off with a few light strokes on a find DMT folding 4 inch hone. Oh and then I ususlly hit it a few licks on a paper notepad.

I have actually just used a paper notepad before and can tell a real difference in the sharpness.

I use the back of a legal pad to strop with sometimes. Seems to work well.

Try newspaper, it works better.

the slotted paper wheel will strop an edge in a few seconds compared to minutes by hand.

I see the advantage of a paper wheel, but I would feel disconnected from my knife. Without sounding too existential, I like the feeling I get when I use my hands as much as possible.

There is no doubt that polishing your Weiner by hand is a great feeling that no machine can replicate.

Seriously, I prefer hand sharpening.

I've never tried to polish my weiner before. I seem to get the same results by just stroking it. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> Oh, on a stone. Let my mind wander for a moment. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Hand sharpening helps me relax, puts me "In the zone". I just feel the steel slide across the hone and listen to the sound it makes and can tell it I have the angle right or not.

i had a guy tell me the wheels gave him more time to chase his old lady around the house <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />. that shounds like a lot more fun <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

I don't normally have a bench grinder with me at work. That's where I do my sharpening, in the wee hours of the morning as a way to stay awake.

Haha. I need to work on my freehand but I have a really crappy stone at the moment and I cant imagine that that will help me out at all.

i offer free sharpening for soldiers (and all the other public servants) and if the soldier has a dremel tool i send a small wheel along that they can put directly on the dremel to touch up the edge in the field. the guys that have tried it out said it works out great.

You can get mini paper wheels for a dremel tool?

steeley, get a piece of 1/4" glass plate and some wetordry sandpaper instead of a stone.

I like a knife to have a coarse edge toward the tip, and a fine edge near the bolster.

i have thought about trying that a few times and never did. it could turn out to be an interesting experiment.

steely, the mini buffing wheels are something that i make from some 1/4" thick scrap pieces from the same material the large wheels are made from. i make them using a 2" hole saw and they work ok out in the field. a humvee has a 110 power converter so they can use their dremel anywhere.

i was talking to a guy who participates in bladesports competitioins and he said a coarse or toothy edge is a better edge to have on a knife when competing.

Ok, what are we competing in? I'm curious as to the type competition we are talking about here.

I have a lot to learn when it comes to sharpening, I have a feeling I have been doing it all wrong.

That is what I have heard from guys that compete and build knives for the fun sport.

SF, I can get some really good working edges on stones but I still want a belt sander and bench grinder for the ease and speed of doing my blades.

SF, they are talking about Bladesports, what used to be called Cutting Competitions that was taken over and made into an organization to standardize all blade cutting competitions with the overall championship held at Blade each year.

Check out that name on YouTube, pretty cool cutting contests involving rope, wood, straws, golf balls and water bottles. A lot of precision is involved in it as well as a sharp knife.

Now, let me be sure I'm getting this right. You aren't talking SHARPNESS but the way the edge is--coarse vs polished. I assume you can have a push-sharp toothy edge. Or am I reading this wrong? I use coarse and fine diamond hones for my Vs and coarse and fine stropping compound for my convex. They get dang sharp and generally seem to hold fairly well.

I know some steels, like D-2 naturally take a generally toothy edge.

Ok, I really don't know what I'm talking about <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />

Haha,they are talking about are the microserratios very course or very fine. In other words do you like a more "toothy" edge(course) or a fine (polished)edge? is that better or did I only confuse you more?

Right, but that doesn't necessarily impact the overall sharpness--just the "toothiness", correct? I'n other words, you can have a toothy edge that's done up with a coarse hone and maybe passed a few times with a fine one, but that can still push cut.

Yes. That is what I do on my knives. Now I do not like a RAZOR edge, to fragile for me, and believe it or not, sometimes a HIGHLY POLISHED edge, will slide where one with more tooth will grab and cut. I get a course "toothy, sharp)edge and hit it a few licks on a fine stone just to even things up and I am done. Always cut good for me that way

A knife's edge is like a saw blade. It has "Teeth". The smaller the teeth the less "Bite" it will have if you will.

Imagine a hand saw wood and a metal saw. Both sharp. One will cut wood like there is no tomorrow and one takes longer and can almost slide off at times. And here I go confusing you again.

Toothiness and Polished are only terms for the edge teeth size and do not necessarily have any impact on sharpness, just how they "grab" the material being cut.

Good explanation Randy. I have tried mirror edges, polished, and all that. I love a nice convex edge, but I find myself doing more of the course, medium, and a strop than anything else these days.

Course Edge.

I use my knives...hard...and a course edge retains longer.

I have found a more coarse edge is better for hard use. In my own personal opinion.

Had my say above and still hold to it. For a USING blade, I feel as if a course edge is better than one taken to a mirror finish.

S/S is right.

Yup, I agree also.

So does Gary.