Sharpening - General

Q

QuietOned

Joined
Sep 4, 2005
Messages
157
Sharpening a knife, axe, chisel, or anything with an edge isn't difficult. It isn't magic. There are no secrets to sharpening. Ok 1 secret. You thin out the edge of metal/ceramic/glass/stone to where it cuts, the thinner you get the edge the sharper it is. That's the only secret.

Convex, single bevel/chisel, double bevel all depend on the same thing, get the edge thin enough to cut. Sharpening is thinning it out so it will cut. Everything else is just methods and details.

Mistakes people make in sharpening and why they give up trying to learn. They don't see results. That's number one and usually 90% of why. People expect instant results and when they don't see it they become totally discouraged.

You can cure that by using a couple files and have a decent edge too. Get a good quality carbon steel blade C-Clamp the knife to a work surfact and put the bevel on with a heavy coarse mill bastard file. Hold the same angle on the file and push. You're sharpening. Keep the file angle consistent to the blade. Work in two inch wide strokes keeping the file parallel/square to the blade face, you may have to rotate the knife when you start working the tip to keep it square to the file. Do one side until you feel that burr, the edge folding under, all along the total length of the edge. Then do the other side exactly the same.

Tidy it up with a fine file the same way. It'll cut as is or you can polish it up with 320 grit paper wrapped around a ruler and held with a bulldog clip. Finish it off with 400, 600, 1000 grit paper if you want. The first time you sharpen anything so that it actually cuts will encourage you to keep going.

Ok you've put an edge on with the file and it cuts rope well, but it might not slice paper to well and it doesn't shave the hair off your arm. But be happy it cuts and you are more than half way to screaming, hair jump of your arm at the approach of the blade sharp.

If you have refined the blade edge and polished it with wet dry paper on a ruler and gone to 600 grit it very well may shave hair. It will if you a) held the file and ruler angle consistent. b) didn't "push" but let the files and the paper do the work.

If you take a good quality carbon steel blade and use this method go slow. Give yourself 1 hour on a 8 inch chefs knife. You will have it sharp enough to use and then some. For a lot of people having the knife stationery and moving the cutter (file, stone, paper over a ruler) is easier to grasp than pushing the knife into the cutter. There is a more natural hand eye co-ordination.

Give it a try. If you like it you're more than half way there. I'll post more if people are interested.
 
Hope it's ok to add to this thread. I think this is a good thread for hand sharpening. Basic, demystifying information for new folks who are intimidated by the thought of sharpening a knife/axe/cutting tool by hand. Everyone, repeat after QuietOned .... "It isn't magic, It isn't magic, It isn't magic".

It takes practice and patience. If you were told to go out and use the sidewalk to sharpen the edge of a popcicle stick to make a toy knife I bet you could. If you can do that, then you can sharpen nearly anything.

If your sharpening a knife by moving the knife and not the sharpener you can try using the sharpie pen method to ensure you are getting the edge. I think sometimes people start out with too fine a stone and are on the shoulder and/or are not hitting the actual edge. For the tips, you may have to lift the end you are holding onto a little to maintain the edge angle.

Try this, "karate chop" your table so that your right hand it perpendicular to it, pinky on the table thumb on top. Move your hand to 45 degrees, now move it to half that (22 1/2 degrees), tilt it a skosh more. Now, slide your hand from left to right across the table in an arc. As you get to the tips of your fingers you will want to lift your palm/wrist so that just the tips of the fingers are sliding across the table. If you can do that, you can sharpen a knife.

Don't get too hung up on the angle thing, it's more about consistency. Just remember, too thin and the edge won't hold up ...... too thick and it won't slice all that great, might make a good chopper though. :)
 
Yep! - both these guys got it right.
The thing about the 'relief' (angle) on the edge is real important; most factory edges don't have enough for optimum sharpness; more relief costs more money to produce.
If you want *razor* sharp, work 'em down a bit; I usually do it over time, - every time I need to sharpen, I increase the relief a little, untill I have it where I want it.
Flat will cut better than convex, concave (hollow-ground) the best, but usually impractical in most cases.(most knives)
Also it *is* worthwhile to polish the edge if you want top sharp.
A polished tends to not feel as sharp - nothing left in the way of microscopic grind/tool marks to produce friction; don't worry, it's a definite improvement.

- One thing - the best hand sharpened blade will never, never, never, be as sharp as a blade sharpened with some sort of a guide or jig, to maintain a consistant angle; and the better the jig, the better the job.
- This tends to irritate the crap out of some of us, I was no exception, but finally had to accept this ego crunching reality.

- For those new to the game, the "razor edge sharpening book" explains it pretty well; I think it's worth the read.
 
That above statement on the hand sharpening vs jig. This assumes too much. The jig is only as good as the user and the abrasives it's using. I've seen many a piss poor sharpening job done on a jig, and I've seen hand sharpening jobs that look like they were done on an edgepro.

Now given a user of great skill familiar with both a good jig setup (like the edgepro) and hand sharpening, you're probably right. Someone who might be a totally mediocre hand sharpener may find a jig that works perfectly for him and produce fine edges, but it's all up to the user in the end.

Oh, and one more thing ;) Polishing the edge is only good for show and woodworking tools IMO (including knives used as choppers). Otherwise a push shaving sharp rough finished edge works best. I prefer 600-1000 grit, followed by a light stropping.
 
yoda4561 said:
That above statement on the hand sharpening vs jig. This assumes too much. The jig is only as good as the user and the abrasives it's using. I've seen many a piss poor sharpening job done on a jig, and I've seen hand sharpening jobs that look like they were done on an edgepro.

Now given a user of great skill familiar with both a good jig setup (like the edgepro) and hand sharpening, you're probably right. Someone who might be a totally mediocre hand sharpener may find a jig that works perfectly for him and produce fine edges, but it's all up to the user in the end.

Oh, and one more thing ;) Polishing the edge is only good for show and woodworking tools IMO (including knives used as choppers). Otherwise a push shaving sharp rough finished edge works best. I prefer 600-1000 grit, followed by a light stropping.
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Yeah, you are quite right yoda - I've seen the same thing myself - bad jobs done where good ones should have been produced.
- I suppose I should have made the point, that a jig will produce a better edge than the hand sharpened one, if the sharpening skills are equal.
In fact , what I had in mind was a highly skilled person doing the job in both cases.
Did actually say "best" in regard to the hand sharpened blade.
Did not, in the case of the jig.
- I qualify in both cases as a journeyman I suppose.
- jig is best; and so far the edge-pro is the best I've used.
- my custom knives are all from one maker; considered to be one of the best hand sharpeners world-wide.
- I can get 'em sharper with the edge pro- not that much, but noticibly so.
- and he beats the ass off me for hand sharp - mostly holds a more consistant angle.
- still - I can shave with mine - so I'm O.K. with that.

- don't understand your info on polished edges - I sharpen to razor-sharp and the finish off with 1000 and then 3000 grit.
like mirrors - tool marks gone - just the mean surface left - highly polished.
less friction, blade needs less pressure to move through the medium it's cutting.
- more friction, blade needs more pressure.
also the tool marks (grinding marks) produce ridges above the mean surface- they break down fairly quickly and the integrity of the edge is compromised in a way the polished edge is not.
The result is, the blade simply dulls faster.
- regardless, the important thing is, the edge with less friction takes less force to make the cut; and although it may be a bit academic, it will cut better.
Standard machine-shop physics.

-
 
3000 is probably still "rough" enough for me to consider it not polished. Polished to me would be the knives that have edges buffed on a wheel (like many custom makers are apt to do, as well as production factories) that can only shave, and can't cut worth a damn (I'm lookin at you here Cold Steel). There is no tooth to the edge, and while it'll cut paper/small string/flesh/shave extremely well, try cutting a 1 inch poly rope and you'll just find the edge sliding off.
 
yoda4561 said:
3000 is probably still "rough" enough for me to consider it not polished. Polished to me would be the knives that have edges buffed on a wheel (like many custom makers are apt to do, as well as production factories) that can only shave, and can't cut worth a damn (I'm lookin at you here Cold Steel). There is no tooth to the edge, and while it'll cut paper/small string/flesh/shave extremely well, try cutting a 1 inch poly rope and you'll just find the edge sliding off.
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like I said, mirror.
and how about 10, 1 inch ropes in a bundle?
- one clean swing- all cut through, sweet and clean.

- guess we be talkin' about two different things.
 
For me and my every day pocket knives, I get it sharp and burr free on my Fine India stone, few swipes on a ceramic rod, done deal. I kind of like my edges a little "toothy" and I don't mind if it needs touching up, I like to do that. Anyhow, they stay sharp for a decently amount of time through a variety of tasks.

I thought the idea with this thread was to de-mystify knife/cutting-tool sharpening by keeping things simple. Though I think it's ok to say what you prefer and why for general information, just to give new folks an idea of what experienced folks are doing and why. And also try to explain in simple terms how you achieve what you like.

So, please guys ...... let's not get bogged down in the "my finished edge is better than your finished edge" debate. Everyone is different and has different needs, preferences, and abilities.
 
yam said:
For me and my every day pocket knives, I get it sharp and burr free on my Fine India stone, few swipes on a ceramic rod, done deal. I kind of like my edges a little "toothy" and I don't mind if it needs touching up, I like to do that. Anyhow, they stay sharp for a decently amount of time through a variety of tasks.

I thought the idea with this thread was to de-mystify knife/cutting-tool sharpening by keeping things simple. Though I think it's ok to say what you prefer and why for general information, just to give new folks an idea of what experienced folks are doing and why. And also try to explain in simple terms how you achieve what you like.

So, please guys ...... let's not get bogged down in the "my finished edge is better than your finished edge" debate. Everyone is different and has different needs, preferences, and abilities.
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- good point.
starting to regret joining this forum.
my texts really were to answer the 'general sharpening' questions.
- not to produce opinion and debate -
- lots of confusion, it seems re: polished edges.
should have left that one alone.
- certainly not required for a razor-sharp edge. -

- happy cutting !!
 
Don't regret joining man, just roll with it. :)

You guys have differing opinions, it is quite common here, and is usually alot of fun to read a couple differing perspectives.

I would say some, find that a polished edge is the way to go, and others that find a toothier edge thier thing, mine is the polished edge mainly, this works well for me for my good knives an a toothy one for real crap work.

I am suprised, the Big guns in the forum have not made thier wisdom known here yet, usually Cliff S would put the smack down on this and show us the light for either, or Jeff C with with his combo "Polished-toothy recurve" and Joe T and his angles on knives..i am hoping they are putting thier wisdoms into definitave reprints here in the Toolshed forum for us an others to come.

One thing i can say, there's many ways to achieve the same goal, and this can confuse people a bit, and others they never heard of before.

And the people cry out for reprints here made sticky like :D


WR
 
I'd say Yam pegged it most use way to fine of a hone/stone when sharpening and shaping the edge. I'd also say it's so much easier to start coarse and move up to higher grits in steps don't just jump from coarse to very fine. I also agree with Yoda about 1000 is the most polished I like. Btw he said polished for wood working and choppers and 10 ropes cut in 1 swing is most likly a chop.
 
Do you guys who sharpen by hand/feel ever go through a slump? It seems like some days I can't do anything wrong when sharpening. Then I go for days or weeks at a time where I can't get an edge the way I like it no matter what I try. I get to about 98% of what I want, then when I keep going I ruin it, as if I'm pushing too far.

Maybe on my "good days" I'm just satisfied with that 98%!
 
G.R. don't regret joining this forum a friendly disagreement is a good thing. However, I don't think you and Yoda are even disagreeing. He did say polished for choppers.
Yep I also will get in a slump and cann't seem to get an edge just right.
 
gord ... I'm sure it's been discussed ad nauseum elsewhere, but wouldn't the type of steel and heat treat make a big difference as to how a given knife performs with a highly polished vs. a "toothy" edge?

Are most of your knives plain carbon or tool steels?

I mention it because it seems like the lower the grade of steel and/or heat treatment, the more it needs the "teeth" to slice well. I know that I've had good results with knives made from old files with highly polished edges, but with a lower end stainless blade and the same level of polish, it tend to just skate across something like rope. Since most of my knives are stainless, I got better results when I switched from Arkansas stones to diamonds.

Of course, I could be wrong. I don't do much "testing," per se. I just sharpen 'em to the best of my ability and then use them.
 
I have good days and bad days I suppose, but not too many. I try to make sure I have the time to take my time and not be rushed so I can enjoy what I'm doing. I go relatively slow, and make sure I stay consistent and concentrate on what I'm doing. I have only been free-hand sharpening for about a year so I have to pay attention and I have lots left to learn.

As for Cliff, Jeff and Joe, they have forgotten more about sharpening than I'll likely ever know and they could do this stuff in their sleep I imagine. I can't tell you how many threads I have read, a few books, literally hours upon hours of reading. I finally just made up my mind to give it a try and take it slow. I can get a decent edge on my knives, with an even bevel, and not totally scratch the blades all up.

I think the reason so many folks have drawer queens is they are somewhat afraid to dull them because they aren't comfortable sharpening them. It's a shame really, because being able to put a usable edge on your knife kind of sets you free to actually use the thing for what it was designed for. It's also not necessary to buy an expensive knife sharpening system either. For under $20.00 you can have decently sharp knives. Besides, once you get comfortable sharpening by hand (or by any method) you realize it's all pretty fixable or you can make adjustments if you don't get the desired results.

gord, stick around and post, it's all good stuff. I just didn't want to see things get bogged down with the edge/grit debate.
 
rhino said:
gord ... I'm sure it's been discussed ad nauseum elsewhere, but wouldn't the type of steel and heat treat make a big difference as to how a given knife performs with a highly polished vs. a "toothy" edge?

Are most of your knives plain carbon or tool steels?

I mention it because it seems like the lower the grade of steel and/or heat treatment, the more it needs the "teeth" to slice well. I know that I've had good results with knives made from old files with highly polished edges, but with a lower end stainless blade and the same level of polish, it tend to just skate across something like rope. Since most of my knives are stainless, I got better results when I switched from Arkansas stones to diamonds.

Of course, I could be wrong. I don't do much "testing," per se. I just sharpen 'em to the best of my ability and then use them.
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Mostly forged carbon, clay tempered, and samurai, C/T - my experience has been that low grade steels (softer) can not be developed to the same degree of sharp as the harder steels -carbon or not.
- and never bother polishing the soft stuff; - just can't seem to get an edge to justify doing it - so definitely a tooth, is a better idea on the cheaper stuff. - has that saw effect as the blade moves on the medium to be cut ; *tooth* is like having multiple cutters (blades) set on the edge. Pretty much the best way to maximise a softer blade that cannot be brought to a razor-fine edge.
If you sharpen a soft steel to it's optimum 'sharp', and then look at it with a 60X glass- you will see an edge that is very broken up- the steel will just not hold together to the point where we get the 'razor' - and in fact, we be looking at the 'tooth' .
High grade stuff will get to the 'razor' - looking at it we'll see some very fine 'tooth'; and this is where the polishing will be an improvement -removing most of this (VERY fine) 'tooth'.
- and is the reason polished blades often don't *feel* as sharp.
- don't squeeze too hard,
they definitely are!
- I'm no *expert* - this just be my take on it.
- seems to hold true, so far.
-
 
I do like polished edges, I just don't want folks to think they're the best thing for every situation. I've found in my experience that the things I need to cut most often are plastic zip ties, weed eater cord, and poly rope. In terms of plant matter I'm always trimming dead stuff off of the bananna trees, and a fully polished and buffed edge, while able to cut through the live stuff great, just slides on the dry dead parts(this goes for the aformentioned plasting things too). 1000 grit and a light stropping will pop hairs off above the arm, and has enough tooth to easily slice right through anything I throw at it.
 
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