Sharpen for a wire edge

[Andrew Pitonyak]

In my mind, I keep thinking "sharpen until you see or feel a wire edge", but I rarely ever see or feel a wire edge.

If I use my power grinder to remove a bunch of metal, sure, an obvious wire edge. Sometimes on the Tormek when I have a serious rebevel, I might feel a wire edge. I can't say as though I can categorically state "hey, I see or feel a wire edge". In a perfect world, I would have a bunch of friends who know a bunch about sharpening and I could hang with them and feel their wire edges, but, alas, I am the "sharpening guru" for my friends (which says more about my friends lack of ability than my <cough> god like sharpening abilities).

After assuming that I am doing something horribly wrong for all these years, I read something that David Weaver said:

... For modern waterstones, I'd use any medium stone (1000 grit type stone) and any fine stone (8k grit or higher) and then no strop. Waterstones don't allow an organized wire edge to develop like natural stones do, they cut narrow grooves and the wire edge is more like a bunch of little bits of stuff that you can just palm strop off if you need to strop. My favorite setup ever is the shapton 1k pro and the shapton 15k pro.

So, is it because I am generally using something like a Shapton 6K or 15K and by the time I get there I am less likely to have a noticeable wire edge?

Based on Winton Applegate's comments, I should probably compare one of my edges to his. I know for sure that Mr. Weaver knows sharp, at least for saws. I have two saws that he sharpened and they work very well.

I suppose that I should just try the hanging hair test on a chisel to see what happens. Yeah, I know that I don't need it that sharp for most things that I do, but I usually leave my tools as sharp as I can make them so that when I start a new project I can just get to work.

I am not complaining that I am not getting my tools sharp, mind you. A friend from out of state visited me (I see him about once every two years), and he was not using certain tools because he just could not get them to work... until he visited me and he had his first taste of what he considered a sharp tool. He now regularly uses hand planes and such. That was somewhat validating. It is just a question of understanding how sharp they can really be so that I can make an informed decision about how sharp to make it and knowing that I can make it sharp enough when I have that really difficult task to handle. I also know that I produce a sharper edge than I did a few years ago.

So, how can I really understand how sharp my tools are and how much better I can do? Is the hanging hair test really what I should try? If so, exactly how does one do this?

[Daniel Rode]

Here's what I do. Maybe it will help.

For me, sharpening is grinding, honing and polishing steps. Except for perhaps the first grinding, I don't grind all the way to the edge.

When I hone (800-1200) I know I've cut enough metal to reach the edge because I can feel the burr (wire edge) when I run my finger across the back. It's a slight roughness at the very edge. I don't know if I can see it. I don't look, just feel for it.

With something around 1k stone, the burr is easy to feel. Higher grits make it harder to feel. Once I feel the burr, I move on to polishing. I use a 15k stone to polish and the burr may disappear at this point or at least become too fine to feel. Regardless, I take a swipe on the iron back to remove any remnants. At this point I may take a few strokes on a strop and then get back to work.

[Don Jarvie]

Make sure the back is flat. It may look flat but if the tip isn't you won't get the burr on the front. I had a similar problem and it looked flat but the tip wasn't and could never get it really sharp.

[Andrew Pitonyak]

Make sure the back is flat. It may look flat but if the tip isn't you won't get the burr on the front. I had a similar problem and it looked flat but the tip wasn't and could never get it really sharp.

I recently redid some old chisels because the back was not flat and I could never get them "sharp". I mean, they were usable for most things, but, they just were not "sharp". I ended up grinding off to get rid of the back bevel (yeah, it was that bad), and now the backs are flat. I understand that if I use the Tormek leather wheel I need to be careful about getting to close to the edge or it will easily round over the edge. nice tip, thanks.

[Andrew Pitonyak]

When I hone (800-1200) I know I've cut enough metal to reach the edge because I can feel the burr (wire edge) when I run my finger across the back. It's a slight roughness at the very edge. I don't know if I can see it. I don't look, just feel for it.

Do you pull your finger off the edge or along the edge (yeah, I mean on the back, not slicing into your finger).

With something around 1k stone, the burr is easy to feel. Higher grits make it harder to feel. One I feel the burr, I move on to polishing. I use a 15k to polish and the burr may disappear at this point or at least become too fine to feel. Regardless, I take a swipe on the iron back to remove any remnants. At this point I may take a few strokes on a strop and get back to work.

OK, so I should not have a real expectation of feeling a "wire edge" off my 6K Shapton and certainly not off my 15K Shapton. It is rare for me to have to go back to a 1K. To be honest, I don't even remember what my other two primary stones are because I use them so infrequently. I really need to look it up.

[David Weaver]

The hanging hair test isn't something you should really do for tools - it's just a novelty test for them. It's more useful for razors.

If you can pare through something like a medium hardwood with a waxy surface, your tools are sharp. If you see little bits of lines and stuff, the edge has damage, but if the surface is uniform and waxy and the chips stay together well, your tools are sharp with an undamaged edge

For planes, if you can take a shaving that is a half thousandth thick and stays together well and has good structure, you have a sharp iron.

I suspect your tools are sharp. If you generate a uniform burr with the 1k stone and then you polish the edge where that burr was and it disappears completely, you're good to go.

The very first iron I ever sharpened, I sharpened after dutifully watching the charlesworth DVD and literally taking notes and following the steps exactly. The edge planed very well. Since then I saw tales of sharpness from various folks and figured that there must be some secret dimension of sharpness I didn't know. There isn't.

Then when I got into straight razor shaving, there was surprisingly a bit of a learning curve to sharpening a straight razor and really getting it effortless sharp. And then I saw people talking about magical levels of sharpness and figured that there may be something I could learn yet with technique to really get razors that glide through hair. So I bought a brand new razor that had been sharpened by one of the super gurus who charges a fair bit of coin to sharpen razors and...
... it was less sharp than my razors.

I think you're in the same boat. No board ever comes down from the ceiling and slaps you on the head and says "ok, you can wake up now, you know what's sharp".

Funny enough, one of the things I don't get that picky about is saws. I sharpen them more reflexively, and don't get nutty worried about some of the stuff that is talked about (though if you got saws from me, I may have jointed them at the time out of courtesy). I like sharp saws, but they don't need to employ the same level of precision that a plane or chisel edge has.

I remember rob cosman coming on here a few years ago and saying he had only ever seen two properly sharpened irons from students who hadn't yet taken his class. That kind of talk leads people to believe there's some magic dimension out there, but there really isn't. There's two aspects, and one needs to be discussed and isn't enough:
1) getting something blindingly sharp is just a matter of doing the details correctly, it becomes trivial once doing the details correctly is all you do
2) there is a level of functional sharpness that does not need to be a 1/2 micron mirror polish on both sides of the bevel. I always work the back of an iron, including the jack plane iron, but once or twice I've been lazy about the back on purpose and just worked the bevel and stropped off the wire edge and the plane was fine. Functional sharpness is learned in context - it's part of a complementary cycle where you are both learning to make tools sharp trivially and also where you are learning to use tools well even when they're not fresh off of the stones. It's nice that those work together.

#2 isn't talked about enough. I have irons that no "instructor" would be able to say weren't sharp. Novelty sharp, and I have functionally sharp irons that someone trying to sell something to newbies could say "oh, this guy doesn't know what sharp is". That would irritate me, because sharpening in the context of #2 where not everything is submicron sharpening (but you always remove the wire edge if you're doing something coarse that creates one) sometimes makes more sense from a flow perspective than #1.

Strangely enough, the two things that work together with woodworking are also there for razors. If a straight razor doesn't pull, you can use it competently, and you become less dependent on the quarter micron type sharpness that some people love on a razor, but that can be uncomfortable and doesn't necessarily yield a smoother shave.

[Andrew Pitonyak]

Oh, a Bester 500, Bester 1200, Shapton 5000 (why did I think it was 6K?)... I did recently purchase a King 250 / 1000, and boy are they soft.

[David Weaver]

If you want to drive yourself to see what you can get just for novelty, the details of the hanging hair test are here:
http://coticule.be/hanging-hair-test.html

And here is a brief video of it in practice:
https://www.youtube.com/watch?v=UF-ayPofWpY

You can pass it with tools, but I wouldn't by any means use it as a measure for them. If you get a uniform HHT pass at what's described 3 or better in the coticule.be descriptions, your tool is blindingly sharp for tools.

This HHT is also a great thing for people to fiddle with when they're trying to learn the effects of a clean bare leather strop.

[ian maybury]

+1 based on the results of my recent chisel sharpening odyssey - i've been sharpening for ages, but not with waterstones down to fine grits to a properly structured methodology. The magic is in a sense the way such a fine edge more or less automatically materialises simply as a result of methodically following the steps. (basically Charlesworth with much appreciated inputs from David and the guys here - with very frequent flattening of the stones using a 400 diamond plate being a key step) The surprise is that it's becoming clear that once flat surfaces have been established at a reasonable grit finish (set up at 120 and then 400 grit on the WorkSharp in my case) that re-sharpening (and even honing/polishing during initial set up using a single bevel Japanese style) don't require a great deal of work. Next up is figure out by just how much the steps can be trimmed.

I've tried the test since David pointed it out yesterday, and am finding that the waterstones (finishing with a 12,000 Shapton professional) are routinely producing an edge on the chisels that while it takes a bit of jiggling about to get a hanging hair to cut that cut it indeed does. ( not quite Jim's 'cut yourself by looking at it', but still…)

It seems that pitfalls some could be running into on waterstones might be (a) not sticking with the coarser waterstones/whatever flattening method is in use until the flat planes comprising both the bevel and the back surfaces run right through the cutting edge across its full width (care is needed not to leave a small imperfection/section of unfinished edge behind, particularly at the corners); (b) dubbing the edge or otherwise disturbing the two planes as a result of not flattening the stones frequently enough (see Charlesworth), and (c) despite the above possibly not doing enough honing when re-sharpening to get rid of whatever wear bevel may have been present.

Avoiding the latter (since wear bevels form on both sides of the edge) requires either cutting the bevel back enough when re-sharpening to get fully through the worn area. (forming a tiny low angle back bevel as well as cutting back the the front bevel a la ruler trick may reduce the amount of metal needing to be removed to achieve this - but it's not an option on chisels which must have a flat back) The potential problem is that a wire edge can form before the wear bevel has been fully removed. The latter may be more likely if sharpening has been delayed, and the wear bevels are fairly large...

ian

[Derek Cohen]

I've never had any difficulty feeling the wire, even at 13000. What will make this more difficult - even prevent it - is if there is a back bevel. For example, the Ruler Trick on plane blades or a rounded chisel back. Does the steel feel smooth, or can you detect a slight resistance to the finger running back over the edge?

Regards from Perth

Derek

[Winton Applegate]

Wire edge

See now . . .
I been doing it "wrong" all this time because I always MAKE a wire edge. Unless I do I have not taken off the wear bevel(s) and am just polishing metal that has nothing to do with cutting the wood.
NOW
What I am calling a wire edge is just the smallest hint of a thing. I sharpen in the kitchen under halogen spot lights. They may actually be flood lights but they are not an even lighted area. I get under one of them and tilt the blade until I see the wire edge light up. I am using a magnifying visor usually though it can be seen with the naked eye. But extremely small. Almost nothing there.

To produce it I go with either a 700 stone or a 300 diamond or water stone. There a bouts. I tend not to start with a 1000 stone. I never "touch up" an edge. I SHARPEN IT ! Touching up with a strop or a fine stone like a 6000 or 8000 is just folly.

No really.

Use the coarser stone to CUT the face flat and down to the polished back (producing the wire edge) then polish 'er up with fine stone(s) keeping the face flat and in the process polish off the wire edge which can get larger and thinner. It finally comes off on the finest stone as super small little flags of black metal. I NEVER palm strop off a wire edge of any sort. I do palm strop but more as a voodoo magic ritual than to actually do anything in the real realm as we know it. I think palm stropping effects things in the quantum realm and some pretty strange things take place there.

See These Dudes for what I am talking about.
Hay . . . quantum woodworking . . . a whole new forum to add to SawMill.

PS: we were talking about leaders or hero types and who needs em etc.
If I were to list mine they would have to include the dudes in this DVD and at CERN

Michael Duff, Michael Green, Brian Greene, Walter H.G. Lewin, Joseph Lykken

and why they left this guy (Edward Witten) off the list I don't know but he is one of the weirdest and COOLest people I have ever experienced.

[Daniel Rode]

I feel for the burr by sliding my finger perpendicular to the cutting edge. I check the entire edge and once I have an even burr all the way across, I'm ready to polish.

When I stopped trying to get everything perfect, I started getting sharper tools. Hone, polish, a few strokes on the back and I'm ready to cut wood. Maybe 1 or 2 minutes.

Do you pull your finger off the edge or along the edge (yeah, I mean on the back, not slicing into your finger).




OK, so I should not have a real expectation of feeling a "wire edge" off my 6K Shapton and certainly not off my 15K Shapton. It is rare for me to have to go back to a 1K. To be honest, I don't even remember what my other two primary stones are because I use them so infrequently. I really need to look it up.

[Andrew Pitonyak]

Thanks for all the advice. I checked and I can certainly feel the wire edge at about 1000, and I can certainly feel it on the Tormek (I went and I checked).

I tested a plane blade on my #8 and a hair from my daughter's head vibrated but did not slice or shave when I pulled it over it. Easily sliced paper.

A quick test with a 1/2" chisel that I had sitting on my bench totally failed the hanging hair test which did not surprise me.

Winton, I read the first edition of "The Elegant Universe" some years back, I was not aware that it had some material in movie form from Nova.

[Pat Barry]

Really? You had to involve your daughter in this nonsense?

[Winton Applegate]

"The Elegant Universe" some years back, I was not aware that it had some material in movie form from Nova.

Actually it was a mini series so there is more than "some". It may be complete.
Well you just wait my brother.
You are going to be blown away. The graphics are earth shatteringly cutting edge (for the time) and seriously good by today's standards. For instance they are saying things like "well imagine if you were on this 30 story building and you stepped off and were falling . . .

well with computers they do exactly that and the narrator (one of the actual physicists from the list) is talking as he is falling and it looks completely real like . . . you want to stop watching because you are going to see a bloody sick mess any second . . .
yah that well done.

You can buy a two DVD set on Amazon for not much $. Or get if from NetFlix.
TOTALLY WORTH THE EFFORT OF TRACKING THIS DOWN.