How sharp before they go out?

kungfumo

kungfumo

Joined
Aug 21, 2006
Messages
533
Ok kind strange question. Maybe?

I had a customer say that he wasnt super happy with the sharpness of a blade I made for him when he got it. He was very happy with the knife, he just commented that it could have been sharper:o

Now having said that, I thought that it was usable but not scary. I ruffed out the 30 deg bevels with a 600 grit belt (yes lots of cooling every pass, small 1x30 beltsander) I then cleaned up the bevels with a 1000 grit belt, then stroped it with a 1x30 leather belt on the sander no compound (to remove the burr) It push cut paper and shave hair very well.

To me this seems like a very usable edge, but I do understand that some people are very picky. which is fine, but I dont think its very cost effective to spend 2 hours honing an edge either. I figure the customer it going to want to do their own thing with the edge, but I suppose I could ask them how they want it (convex, polished, hand ground, ect...)

I'm curiose what other makers do:
1/. Sharpening and how do you it (sander, by hand, ect...?
2/. How sharp do you go?
3/. How do you test?

Thanks,
Jake Hoback
 
I'm a graduate of "Lowe Tech", but I normally just use stones. If it is a thicker edge (.015-.025) I'll rough it in on a wet grinder first. I never use my knife grinder for this because I put a lot of effort into HT and I'm paranoid about messing it up.

A thin sharp type of knife, I'll usually get it where it will pop the coarse hair on my leg. Otherwise, just shaving sharp.

I think my speed to getting an unsharpened knife sharp went from about 30 min to less than 10 after accumulating some good stones and accumulating some experience. Hell, I'll get my steak knife where it will shave hair in 10-20 seconds.

I assume you're talking about a 30 deg included angle. If you sent a knife out with a 30 deg per side angle, that's probably what they're not happy about.
 
30 degs seems a little thick for anything but big choppers. I try to make hunters and bush knives 20 to 25 degs. While you can make a 30 deg edge shaving sharp, a finer edge will seem sharper.
 
I work them until there is no perceptible burr under my finger. At this point they will shave fine or coarse hairs clean with very little pressure, even if I go from a (well worn) 600 grit diamond stone straight to a strop with red rouge. I strop at a slightly higher angle than I use on the diamond stones so I guess this gives it a tiny micro bevel but I can't speak in angles, I learned to sharpen by feel. Most of the comments I have recieved about my edges involve customers cutting themselves;)
I figure (somewhat ignorantly perhaps) that customers who have pet edge styles and sharpening techniques will probably take the blade to a stone, or whatever they use, soon after getting it anyway. When a knife is brand new I am usually obsessive about keeping it sharp, and if it is a user it usually dosen't take me long to knock an edge off.
 
Oh sorry about that, ya it was a combined edge. 15 deg on both sides.
and yes it was a chopper so I left it a bit thick.

More or less I'm just looking to see how every one else does it.

The knife was arm hair shaving sharp, sometimes some people expect a bit more than that? I understand the mistake I made in the last knife, should have made it as sharp as all the others but hindsight being 20/20 in all.

Any body else? I wouldnt mind getting a bigger consensus.
Thanks,
Jake
 
kungfumo said:
I'm curiose what other makers do:
1/. Sharpening and how do you it (sander, by hand, ect...?
2/. How sharp do you go?
3/. How do you test?
Click to expand...

I use a worn 220 grit to establish the edge and create a burr. I run it really slow to avoid excess heat. I'll sometimes buff the edge with light pressure afterwards. I then finish the edge by hand using ceramic stones.

If it will shave hair across the entire length of the blade, then it's sharp enough.
 
customers like knives sharp, if I bought a custom/handmade knife I would like it hair popping sharp.
 
How sharp? As sharp as I can get it! ;)

Then it goes out with a letter stating all about my knife business, what the knife and the handle are made from and the process under which the knife was produced, with a disclaimer that if you cut your darn fool finger off, :eek: it's on your dime! I accept not responsibility for injures once the knife leaves my hands! :D

I kind of hate the disclaimer but in this day and time I feel it is a necessary evil! To many sue happy people out there:thumbup:

Oh before someone says it "I know there hasn't been a disclaimer worte that the right lawyer can't beat", however I feel the disclaimer does give me a fighting chance!!!!!!!
 
I think the real answer here is that a knife should have an edge applied that works for the intended task(s) that the knife may/will see or is expected to do. How this edge would be applied is what is figured out while testing your edges at the task(s) at hand.
 
It should so sharp that it will cut a shadow. Sharp enough to shave a sleeping mouse without it stirring.

It should be hair-popping, scary sharp.

The customer then knows what it is capable of...that's how sharp.

CW
 
Realy depends on the knife, I like a "working edge" on most of my hunters, I sharpen on a fine india stone and touch the edge up on a meduim arkansaw stone. Not enough to get rid of the micro serations, but enough to make it shave and to get rid of the wire edge. On a small folder or such I might buff the edge, but I rarely do that. I like a sharp edge that will stay sharp, not a polished edge that will slice cigaret paper but will not bite into heavier materials. For a choper I would go with a rough edge, polished enough to shave a bit, but still course enough to last a good long time working.
 
Hey there!! Yep, putting in my two cents worth. I don't make big knives, so my technique might be different than what you would need. Maybe not.

I start by very carefully putting a bevel on with a 220 grit belt. Then I go to the stone (carborundum). When I have the bevel I want and it is sharp, I flip over the stone to the India stone and finish up there. It leaves a working edge that will last. This is the Wayne Goddard technique, except for maybe the 220 grit part. I don't know what he does for the initial bevel. I don't take the time to get them razor sharp. Getting it that sharp might blow up in your face, anyway, as it won't last as long and your customer might think your knives won't hold an edge.
 
DaveMartell said:
I think the real answer here is that a knife should have an edge applied that works for the intended task(s) that the knife may/will see or is expected to do. How this edge would be applied is what is figured out while testing your edges at the task(s) at hand.
Click to expand...

yeh that
i have about 4 main edges that i put on knives/razors the 2 that are closest to each other are razors and hand honed sushi knives both go to 16k grit
 
True story: A friend of mine once asked Gary Randall (of Randall Knives) why his knives don't leave the shop razor sharp. His response? "What's the matter, you don't know how to sharpen a knife?"

Well, I do, and I don't really care all that much what condition the edge is in when I get the blade. I'm probably going to put my own touches on it anyway.
 
Dave Martell made a very good point in his sharpening lecture at Ashokan.

Most all kitchen use knives made by "Knifemakers" have way too much meat behind the edge. It doesn't matter what the edge angle is if it gets thick too fast.

On your next chopper, make it as thin as you think is right, and then thin it down a good bit more. It will probably still be too thick for many chefs. The result will be a blade that sharpens well, gets scary sharp....and cuts rapidly and smoothly. The first two of those items are nice but it is the last two that matter when cutting food all day long.

Final comment:
If you use a belt grinder to do the edges it will make a rounded edge. That will appear to be sharp, but will cut poorly on most kitchen tasks. Use flat stones and go to a very fine finish...at least 1000, prefferably 4000+. You will be amazed at the difference.
 
you got a good point there, I tried a ceramic kitchen knife, it cut OK and held an edge great. I don't like it, it's got a short bevel and thick edge section to keep from damaging the fragile edge. As a consiqunce it doesn't cut that well.
 
I think shaving sharp should be passable for any knife, but if you want to go beyond that, you need some kind of test or tests for it. You need to define "scary sharp".

Some knives will shave, but they won't pass harder tests. I use three different test using human hair for degrees of sharpness. The first level is shaving, the second is popping a "hair loop" and the third is a standing hair.

For the hair loop test, I take a hair and double it over into a loop with about a 1/4 inch radius and hold the loop in my left hand between the thumb and index finger. Then, push the edge against the outside of the loop and pop the loop with no slicing motion, just the tension of the loop against the edge.

For the standing hair it's like the hair loop test but no loop, just about 3/8 inch of hair standing up. I do use a slicing motion with this test.

The hair loop test is sort of my standard edge, (before it leaves the shop), but I do different edges on different knives for different reasons.

There are other test that will show the same thing, but I've grown accustom to these three.

I use Arkansas stones and a strop. It usually just takes a few minutes to put the edge on by hand.

Any knife with a bevel behind the edge will thicken up with use or repeated sharpening as the edge wears back. On knives that "I use" a lot, I hone the bevels just behind the leading edge with a course stone to thin it out a bit, before proceeding to the leading edge. Of course this does scratch the bevels, but it keeps the meat behind the leading edge down.
 
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Thanks for all of the comments boys, I appreciate it.

Seems like some like it scary sharp, and some like it usable.

Guess I should have put up a pole:) I think I will be getting them sharp enough to pop hairs like Tia Goo says, sounds good to me, then if the customer wants to down grade the edge thats their choice.

Thanks,
Jake Hoback
 
I think there is a big difference between a "maker's edge" and a using edge. On the kitchen knives I use, most of the time I just slap a burr on it with a few strokes on course stone,… and get to it. On the other hand though,... nothing wrong with a "showy" polished maker's edge... some customers expect that on certain knives.
 
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