Edge seems sharp but won't shave

R

RAGS

Joined
Jul 11, 2000
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Can anyone offer some advise please? I recently got myself a wicked edge sharpening system. I tried it out on my trusty cold steel recon-1. I started with the 100 grit and went through all stones up to 1000 grit,following the instructions all the way. Angle was 20 degrees on each side. Here's the problem. The edge does seem "wicked sharp" and polished. It slices paper effortlessly and catches on my fingernail. It grabs the skin on my thumb wanting to slice into it when I test the edge. It seems super sharp in every way I normally test my edges except that it won't shave arm hair now.It just seems to slide off my arm and might take a hair or two with it.I should add that I usually can get hair shaving edges with my sharpmaker. I'm trying to sort this out before I try another blade on the wicked edge. Any ideas why the edge seems so sharp but isn't hair popping?
 
Ive never successfully shaved hair with even my sharpest knives and I find it to be a silly practice.
 
It is kind of a silly practice, but so are many of the things knife enthusiasts do. It is one of the standard ways of testing sharpness and I can understand why the OP would want to see if his knives are up to snuff.

First thing to do is try DaddyO16's advice. The angle is important.

If you're using a Wicked Edge, I suggest you go over to the youtubes and look for some wicked edge videos by jdavis882. He has good sharpening videos generally, but he recently got a WE and had some troubles getting good edges with it at first. I think his issues were related to slop/play in the mechanism that allows the arms to articulate. Basically the angle would vary slightly as the stones were used, and the edge would not get apexed consistently. He has several videos where he demonstrates the problem and his various solutions.

Since I do not own a WE, I can only give you generic sharpening advice. Slicing copy paper is not an extreme test of sharpness (although plenty good for practical uses). Try some newsprint or phonebook paper, and see if you can pushcut (i.e. cut through the paper using only one spot of the edge. I usually do this by holding the blade still and pulling the paper through the edge). A good shaving edge should be able to do this. Any edge I've made that could do this, could also shave. Keep in mind that 1000 grit is still a little toothy, and will not push cut quite as well as a finer edge, although in my experience it should shave arm hair.

If it snags cutting newsprint or phone book paper, you either have a burr remaining on the edge, or possibly you did not fully apex the edge. A quick way to correct either problem would be to put on a microbevel: raise the angle from 20 per side to maybe 22, and take just a few passes (using very light pressure) with your 1000 grit stone. I would not normally put a microbevel on a 40 degree edge, but as an experiment you could try it. You can remove it easily by going back to 20 per side with a coarser stone.
 
RAGS said:
Can anyone offer some advise please? I recently got myself a wicked edge sharpening system. I tried it out on my trusty cold steel recon-1. I started with the 100 grit and went through all stones up to 1000 grit,following the instructions all the way. Angle was 20 degrees on each side. Here's the problem. The edge does seem "wicked sharp" and polished. It slices paper effortlessly and catches on my fingernail. It grabs the skin on my thumb wanting to slice into it when I test the edge. It seems super sharp in every way I normally test my edges except that it won't shave arm hair now.It just seems to slide off my arm and might take a hair or two with it.I should add that I usually can get hair shaving edges with my sharpmaker. I'm trying to sort this out before I try another blade on the wicked edge. Any ideas why the edge seems so sharp but isn't hair popping?
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If shaving arm hair is the only thing it can't do, I generally don't worry too much about it. I don't put too much faith in shaving hairs, as a reliable 'test' of a good edge. Having said that, lots of variables can make a difference:

1. Hair itself is notoriously variable and unpredictable, in how it reacts/responds to a cutting edge. Even the same hair, on different days, will behave differently at times (humidity, and moisture in general, makes a huge difference).
2. Even the slightest rounding or asymmetry of a very sharp edge can make an immediate impact on shaving. This includes the possibility of a very small wire edge which, if it's leaning one way or another, can make hairs just 'slide away' from the edge. One way to look for asymmetry, is to try shaving from each side of the blade. Maintain same direction of stroke, through the same area on the arm, but flip the blade over and check how it shaves from each side. If there's a bit of a 'leaning' wire edge, it'll more likely shave when it's leaning or curled downward into the hair & skin, and it'll slide over if it's leaning or curling upwards. Similarly, you can sometimes feel this asymmetry when testing the 'bite' on fingertips. Turn the blade around, and feel from both sides, to see if it seems duller from one side, than from the other.
3. Edge angle probably makes the biggest difference. There's good reason why shaving razors are so very thin at the edge. I sometimes have trouble shaving hairs even at ~15 degrees per side. When I've gone much lower than that, shaving gets much simpler. A 20/side edge might be a challenge for some, to make it shave consistently.
 
Light, LIGHT pressure! That was what ended up turning the trick for me in the end. I found that I was simply using too much pressure on the 1k diamonds, and not spending enough time with the strops. Back the pressure you're using on the 600, 800 and 1000 down, especially on the 1000 until you can just barely feel it contacting the blade at all. Then strop the bajezus out of it with the 5u and 3.5u.

When I finally figured out the touch just right, my edges went from more or less like yours (felt sharp, but wouldn't shave) to ones that would raise eyebrows and soil pants, in the span of about three blades. There's a certain feel to it. Also, the rods DO have some play in them. Simplest method for dealing with that is to just make sure they are indexed fully one direction before you start your stroke. I usually used "rod bottoms fully in" to make sure each stroke was consistent. Clay just recently supplied me with a modified set of arms that solves the problem ENTIRELY by replacing the pivot pins with adjustable screws, and adding bronze washers like a folder's joint to completely remove the play.
 
I just sharpened my Case Copperback SS w/Blue Bone last night on my Edge Pro and it's the first knife I have go to shave almost clean in one pass(out of 7 knives sharpened on it). It's actually quite thick behind the edge(warnclif) and I sharpened it to gasp 48* inclusive(24 per side). . My key is light pressure and flat stones.

The biggest tip I can give is the sharpie trick. I have a loupe, an AngleCube, and my sharpie gets used most even with my drill stop collar.

When you switch stones, take the time to mark the edge, and make sure you are hitting it perfect. Take the time to do this step and it will help I promise. I thought I didnt need it with my setup, but I was wrong. USE YOUR SHARPIE and you will get scary sharp every time. Proof: I can shave with a 48* inclusive edge on a rush job with my EP.
 
Thanks guys,I knew I came to the right place with my question.:thumbup::DI'll check out those youtube vids and try light pressure on those 1000 grits(don't have the strops yet) as well as some of the other tips.Thank you for the help.
 
Oh...make a strop. Hobby store, balsa wood. Use it bare or pick up some rouge from a place like Sears to help polish the blade. You dont need a kangaroo leather strop with 0.000000001 micron diamond paste to strop with. I use hobby store balsa wood with 0.5micron chromium oxide, and it makes a huge difference. Get balsa wood, attach it to a paddle and adjust for your angle change and strop away, that will help get rid of any burr, or even do it free hand.
 
you need to go much higher in grit to get a nice shave especially if you wanna try to shave your face with your knife. you also need a higher angle.
 
peeper said:
you need to go much higher in grit to get a nice shave especially if you wanna try to shave your face with your knife. you also need a higher angle.
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To face shave, yes. To just shave any body hair then, no, that is a myth. The knife should be sharp from the first stone and in the case of the OP using a 100 grit it might not shave but should slice printer paper. Moving on to a 220 or 320 grit stone the user should be able to achieve hair popping sharpness and that would be directly off the stone.

If you cannot easily shave arm hair or slice news print by 1k then you probably messed up in the start of the sharpening process.
 
knifenut1013 said:
To face shave, yes. To just shave any body hair then, no, that is a myth. The knife should be sharp from the first stone and in the case of the OP using a 100 grit it might not shave but should slice printer paper. Moving on to a 220 or 320 grit stone the user should be able to achieve hair popping sharpness and that would be directly off the stone.

If you cannot easily shave arm hair or slice news print by 1k then you probably messed up in the start of the sharpening process.
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Dang, 12 posts in and you finally say the most important part yet, highlighted in red.

The sharpest knives edges I get, are stone cold arm hair shaving, newsprint slicing monsters off my Chosera 400 before moving onto finer stones(I reprofile easy steel like 1095, Case SS, even 154CM with my Chosera 400). Now, they are pretty toothy at this point, but even just a couple passes on each side with a strop cleans them up a bit and I have a great EDC edge. Take your time at the lower grits and test it's sharpness as often as you want. I'll slice up 10 sheets of phone book paper before I am even at my Chosera 3K.

Believe me, it has taken me plenty of tries to really get my edge how I want it coming off of my 220, and 400 stones. But...I enjoy it. Man, sharpening is just in the details.
 
Razorsharp-Travis said:
Its a silly practice cause you cant do it ;) ... when you achieve that sharpness it will become your standard test probably :p
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I do find that any sufficiently sharp knife will shave armhair with no trouble. The following vid was done with a GB that hasn't been touched up for a week of light EDC use.

[youtube]wccP1D9iw-8[/youtube]
 
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