How do you test how sharp your knife is?

[OutofGum]

Sometimes I sharpen my knife a bit and can't tell if there's any difference from when I started. Sometimes I'm not sure if I should keep on going, or if there's no point. How do you guys decide when to stop? How do you know when its sharp enough?

Is there any scientific or at least semi-scientific way? I mean theres the hair shaving test... but that never worked for me, maybe I'm doing it wrong. Paper test? Rubber band? Problem with those is that they can be done in different ways using different materials. What do you do?

[talonturbo]

I do a few full blade slices at paper im holding in the other hand. Printer paper. I slice slowly, and if it's any less than a laser cut from any portion of the blade, I keep going.

[JD Spydo]

I do a few full blade slices at paper im holding in the other hand. Printer paper. I slice slowly, and if it's any less than a laser cut from any portion of the blade, I keep going.

I do that myself with the paper. However, if you really want that puppy sharp there is a really good test. Easy to perform if you have the right paper. There used to be an old typing paper called " Onion Skin". I understand it is still available (probably at an office supply store). That is the most flimsy paper I have ever seen. It is comparable to the old cigarette rolling paper. If you can get your blade to a really highly polished sharp it will even cut through that type of paper. I keep a packet of Zig Zag rolling papers with my Razor Edge sharpening kit for that purpose. It really does take some patient work to get the blade that sharp. ON a :spyder: video I saw Sal once cut through paper cutting in curves & circles. It usually has to be a lot sharper than normal to accomplish that degree of sharpness. You just have to experiment and get a feel for it. :) :spyder: :)

[talonturbo]

I've tried thinner paper too (like junkmail flyers) and they are harder to cut. But I like the fact that printer paper shows a fuzzy edge if the blade is sharp but not SHARP.

[JD Spydo]

I've tried thinner paper too (like junkmail flyers) and they are harder to cut. But I like the fact that printer paper shows a fuzzy edge if the blade is sharp but not SHARP.

One other thing I have experienced also there "talonturbo" is a hair shaving test. About a year ago a good friend of mine brought over his Schrade skinning knife and wanted me to put an edge on it for him. Well we talked for about an hour while I used 5 different sharpening stones. The last one being an old Arkansas " blue-black" stone. The guy I got that one from said that superior grade of novaculite was mined completely out many years ago. I use it only for a final finish. I stroked that knife on that stone about 90 to 100 times on each side. Steve ( my friend) actually used it to shave some whiskers right off his face and you could literally hear them poping off. I had also stroped it really good on a high quality strop as well. I will never forget that minute "poppin" sound. I have only gotten a blade that sharp a couple of times since. It really takes some work . It took about an hour. :cool: :spyder: :)

[vampyrewolf]

I've gotten a feel for it over 15yrs+ of sharpening freehand, can tell how the edge bites on a stone if it's the right angle and how long to go on it. I sharpen according to what the knife ends up used for.

My everyday beaters get a 30deg edge on the whites till it shaves, then a quick de-burring with the 800grit AO at 40deg. The small dropped carry gets a 40deg edge on the white flats and stops there.

My 'fly has as low an angle as the blade grind allows, around 12deg inclusive. With an edge that fine it's essentially a razor... the spydie whites and my strop with veritas green (0.5 micron) ensure that.... my left arm is bare as it is...

Been carrying the fb01 moran for over 2 weeks now(oct 29th or so)... strop it every night to keep that edge in top shape. Convex edge is staying there. 2.0 micron compound will shave, but I keep it with 0.5micron which just slides.

All 3 types of edges will fillet paper with no problem. Both my bone kiwi and sheffield lambsfoot will slice cleanly through foam earplugs without compressing it at all. My frn/se endura has been polished up and I haven't found anything yet that doesn't slice like butter.

[severedthumbs]

Once it shaves it is sharp enough for me. Don't let your knife get dull and you don't need to resharpen it.

[OutofGum]

Wow... I don't think I've ever gotten my knives as sharp as some of you have. That's way past factory sharp which is typically what I aim for. Never considered spending an hour on it though... I usually spend about 5 minutes, maybe 10. Good thing to do while talking or watching tv, may try that later.

[severedthumbs]

Yeah 1 hour just seems way to long to sharpen a knife. A sword maybe but not a knife blade. I have had blades sharp enough, that the hair falls out before the blade even makes contact :p , in 10 minutes. I also sharpen freehanded, I think it is the best way to go.

[HoB]

My last test, is to fold a junk mail piece of paper (thin) about 2x2 in to a right angle and stand it on the edge if I can cut it down free standing, it is about as good as I can get it.

If you have to cut in the angle on a rough stone first (or have to fix a chip), there is no way that you will get off with less than an hour work without using power tools. Especially not if you are working on S30V. But once you've cut the bevel in, 10-15 min should be enough to polish the edge, it think.

[severedthumbs]

My newest test it to let a silk cloth rest on the blade edge and if it cuts through by its own weight it is sharp enough if not back to the stones.

[OutofGum]

My newest test it to let a silk cloth rest on the blade edge and if it cuts through by its own weight it is sharp enough if not back to the stones.

! That's straight out of the bodyguard. You serious??

[severedthumbs]

! That's straight out of the bodyguard. You serious??

What is the bodyguard? I am as serious as brain cancer. I have not achieved this level of sharpness yet, but it is attainable and I plan on doing it.

[Jimd]

On some of my knives, I like a highly polished edge that will cut paper, etc.

However, on some of my knives, I like a toothy edge that will bite into whatever I'm cutting.

[severedthumbs]

I like some of my knives to bite like an alligator, especially my users.

[Hannibal Lecter]

I have actually been told by several long-time students of the Japanese katana that such sharpness was in fact a myth, a fallacy. They had seen The Bodyguard and accorded the visual effects of the silk scarf scene great accolades, but had never personally witnessed such a feat. Speculation was that the effect was more likely generated by a remarkably *hot* edge than a remarkably sharp one.

This is not to imply that such a feat is *impossible,* but I am unaware of anyone who can personally attest to seeing it first-hand.

In fairness, it is a nice thought, though. Please do let us know should you ever achieve it, including specific details of *how* you did it, as it will certainly give me something new to work towards in my spare time.

[Jimmy_Dean]

Kevin Costner cut Huston's silk scarf in "the bodygard". I usually don't spend all that much time sharpening but do respect those who do.

Spydercos are sharpened on the 204 and to test it, I run my finger on the edge, like a moron. If it grabs my skin, I know it's sharp to my taste.

[severedthumbs]

I doubt I will ever attain that level of sharpness, but I have once seen a demonstration of the feat.

[Hannibal Lecter]

I only wish I had been there to witness it. As it stands now, I have much to occupy myself with over the coming winter in an attempt to duplicate such a feat.

[vampyrewolf]

Need to search and find Sal's post about the rice paper...

if my brain is working anything close to right... he folded a peice and *blew* it along the edge, slicing it cleanly.