Sharpness Epiphanies

[Adam Stevens2]

Was wondering whether others in this group had the same or similar epiphany I had today regarding sharpness in their tools? I've probably been bumbling along for a year or so thinking my blades were pretty sharp, but after today I've seen the error in my thinking. I got myself a set of new Narex chisels from LV and have been working on sharpening up the 3/4" chisel. I probably put a good two hours into it, including flattening the back. Probably could have done it much quicker with a grinder (which I don't have...) but I figure the practice was worthwhile as much as anything. I've never had the same kind of mirror finish with previous attempts.

It's interesting to see what a difference a truly sharp blade makes. I tested it on some scrap red oak and it just sliced slivers away with ease. I guess it serves as a lesson in patience as well, previously I've probably been in too much of a hurry or get tired of it and the results showed.

[Phil Stone]

I had a small epiphany yesterday, when I realized that I should probably get a belt grinder. Flattening the back of a chisel or plane iron with sandpaper on glass takes FOREVER if the previous owner rounded it significantly. Ditto for changing a primary bevel.

[Kent A Bathurst]

Adam - sharpening is one of the few essential "gateway" skills in the rabbit hole into which you have fallen.

Well done. Keep up the good work.

But - 2 hours is pretty long time on NIB chisels......... The first, coarsest, cut might take a while on the back and the bevel, but after that, you only need to remove the "bigger" scratches and replace the with "finer" scratches as you move through the grits. That should move pretty quickly...........You should be more in the 20-minute range, tops......easy to over-do it [says one who knows].

[Jim Koepke]

Was wondering whether others in this group had the same or similar epiphany I had today regarding sharpness in their tools?

It is a common occurrence for one's sharpening to improve over time. Often it is discovered when a new technique or stone is tried. Other times when just a bit more effort is expended in the pursuit of sharpness one discovers a new level of sharpness.

jtk

[george wilson]

Be careful: a belt grinder can quickly ruin a chisel if you are not experienced.

[Adam Stevens2]

Adam - sharpening is one of the few essential "gateway" skills in the rabbit hole into which you have fallen.

Well done. Keep up the good work.

But - 2 hours is pretty long time on NIB chisels......... The first, coarsest, cut might take a while on the back and the bevel, but after that, you only need to remove the "bigger" scratches and replace the with "finer" scratches as you move through the grits. That should move pretty quickly...........You should be more in the 20-minute range, tops......easy to over-do it [says one who knows].

Kent - I would say 75% of the time was spent on the front getting rid of the factory marks on the primary bevel. I did this on a 1000 grit stone and I am wondering if that was the issue. Factor in a bunch of elbow-grease-relieving breaks as well. I do have a 'green' 220 grit stone - would that be too coarse? I also did the entire face of the primary bevel. I'm not sure if that's overkill or not. At least I ended up with a nice mirror polish the whole way up the bevel. I probably spent five-ten minutes on the finer stones and that includes creating a microbevel, which probably took all of a minute.

[Phil Stone]

Be careful: a belt grinder can quickly ruin a chisel if you are not experienced.

I've avoided getting one up to this point, but don't think I can stand removing significant metal with sandpaper-on-glass anymore. Are you referring mostly to the danger of drawing the temper from the blade? If you don't mind me asking, what is your preferred method of repairing and/or changing the bevel angle of blades?

[Adam Stevens2]

Of course my bench is such a mess that I just went to have another play and took a tiny little chip out of the edge banging it on the side of my plane that's sitting in the way of everything. So now there's that.

[Stewie Simpson]

Hi Adam. You should have started off with your 220 stone to complete 90* of the work. Then swapped over to your 1000 stone and repeated the same process. To further increase the sharpness of the cutting edge, rub some green honing compound onto a piece of mdf, and again repeat the same process.

[Adam Stevens2]

Thanks mate, I'll start with the 220 stone for the next batch. Might be able to use it to get rid of that bloody chip too? Tad annoyed I did that.

I've been trying to figure out if that's David Gulpilil as your avatar.

[Stewie Simpson]

Hi Adam. Your probably already know, but when you work the back of the chisel, there is no need to go any higher than 1 1/2 inches above the cutting edge. Same rule applies for most plane irons.

[Gene Davis]

YouTube is great for getting advice on sharpening.

There is a vid with Paul Sellars reviving a wooden jointer plane, one straight from an estate sale somewhere, with I. Sorby iron. He does the back, then the bevel, the "wings," which is what he calls the fadeaway round at the corners, then the secondary, then strops all. No jigs, just diamond stones.

And the signmaker from California, Billy Schenher, shows you how he flattens backs of chisels with diamond first, then waterstones at 8000 and 15000 grit.

But I like the approach taken by Rob Cosner, who raises the backs of chisels and plane irons to maybe a half a degree or so, to just "flatten" the 1/4" or so near the cutting edge.

Before everyone started using the diamond stones, I went and bought the Lee Valley stone pond, and a set of waterstones from coarse up to 8000.

So now I will get into stropping. Ordered just today, Lee Valley, free shipping, a 6" hard felt wheel for the old Baldor bench grinder, and a stick of green compound. Now I'll shop for a wide leather belt in a thrift store, or go see a shoe repair guy to see what I can get, for a piece I can glue to a board, to have a flat strop.

[John Crawford]

I would say 75% of the time was spent on the front getting rid of the factory marks on the primary bevel... I probably spent five-ten minutes on the finer stones and that includes creating a microbevel, which probably took all of a minute.

This will be a big time saver for you: if you are using a secondary micro-bevel, you won't need to spend time polishing your primary bevel. Of course now you are done with it! But next time, you can just work on the back and the micro bevel.

[Chuck Hart]

Gene, just use a piece of MDF for the strop. Load it up with the "green stuff" and have at it. The MDF works well and a lot of people use it.

[Robert Engel]

After reading all the posts, I offer these comments:

1. The only reason for ever putting a chisel or plane iron on a grinder is to hollow bevel. I think you wasted your time getting rid of the machine marks on the bevel. The best way to treat a new chisel is to hollow grind the bevel prior to sharpening. This will cut your honing time considerable because you are just working a secondary bevel, which means taking off less material.

I, too purchased a set of Narex chisels and actually timed myself from start to finish and I had most chisels ready to use in 30-35 minutes.

2. Polish has little to do with sharpness. In fact, I recently read an article that basically proved polishing actually dulls the edge.

3. I disagree about going 1 1/2" in flattening. If you're ever paring out a through mortise more than 2" deep, you will regret this. I generally flatten my chisel backs at least 1/2 way up the blade, or 2-3". Actually, if you think about it, the more purchase you have, the less error you will have when flattening. 1 1/2" is not enough IMO.

4. I generally do not use a honing guide when touching up. Free hand sharpening is a great skill to learn and saves alot of time when you're making a pitstop in a project to resharpen. Every once in a while I have a sharpening session with all my most used tools in which I do use a honing guide just to make sure I clear any errors from my hand sharpening.

I also recommend videos. Lie Nielsen has a good one on sharpening.
I will give you my technique for comparison:

A. Out of the box:
1. Flatten back: I start with 250 grit water stone. Establish scratch pattern examine under light see what I've got to do. If fairly even go to 320 grit diamond stone. Work it until scratch pattern extends across cutting edge and up the back at least 2 1/2" minimal to edges and large area of back (doesn't need to be perfect). Jump to 600, then 1250 grit. I could stop there, but I go to 4000 then 8000 on the back just on personal choice.

2. Hollow grind bevel: I use the LV grinding wheel jig, carefully set to grind just center of bevel, taking care not to overheat steel. The hollow grinding greatly reduces the honing time as you're only honing 2-3mm instead of the whole bevel. Only the edge cuts! A hollow bevel also gives you a reference point for hand sharpening. You can rock the blade to find the angle, slightly raise, and hone the microbevel.

3. Hone: After hollow grinding I use a honing guide and start with 600 grit, then 1250 (these are diamond stones). Then to the 4000 and 8000 water stone. That's as far as I go. Personally, I don't believe going over 8000 is going to make a real world difference in your blade but some people go to 16k and even 32k.

Good luck. You're a beginner and you are wise to "hone" your sharpening skills right from the beginning. But, it is one of those skills that takes some practice. Find what works for you and stick with one method. I have the granite and sandpaper but I never use anymore.

If it helps, these are my stones: DMT extra coarse/coarse & fine/extra fine. Norton 4000/8000 water stone. The 250 is a water stone. I use the 320 coarse diamond stone to flatten my water stones. Flatten water stones before and between each use (very important!). I seldom use a leather strop with polishing paste.

I respect Paul Sellers, but disagree a little with his sharpening in that he doesn't take the edge to a high enough grit, IMO.

[Robert Norman]

Narex 3/4 and 3/8 chisels are always at my bench. One of the blogs I read early on starting woodworking recommended this for chisels: get one kinda big and one kinda small; you don't need sets to start.
They take a pounding and stay sharp for what I use em for. I couldn't agree more that the first A-HA! moment with a good, sharp tool is a bit of an epiphany, just wait till you use a properly tuned saw (if you haven't...)
Once you learn sharp the next step is feel and sound. When you know how a plane, chisel, saw etc... feels and sounds as it's working properly you'll know when it needs a touch up or try a different approach. I've found in my limited experience thus far that this also translates to machine work as well -- router and bandsaw specifically. For me, this is where the joy of the hobby lies.

[Pedro Reyes]

2. Polish has little to do with sharpness. In fact, I recently read an article that basically proved polishing actually dulls the edge.
.

Robert,

Would you mind pointing me to the article, just curious.

Just as a comment, I shaved hair off my arm yesterday straight off 80 grit sandpaper on a granite plate, so the chisel was sharp in some spots at least, but the difference (and I knew this) is the edge does not meet on a line, but rather a zig-zag of tiny little edges which will break very quickly effectively becoming dull. So very interested on the article's take on polishing.

Disclaimer, I also normally stop at 8K, and in my experience, if I am not careful on the loaded leather strop I actually dull my edge when polishing there.

Pedro

[Brian Holcombe]

My personal ones have been japanese natural finishing stones and plain strops, both on David Weaver's rec and both very successful in practice.

I like to get back to work quickly and I like stuff to be very sharp, so I can go back to the finish stone and then the strop or just the strop for days unless I'm really brutal on an edge. I use a big paring chisel practically all day, relieving corners and trimming joinery, ect and every job it has a purpose for is best completed with a very sharp edge. If it starts to get dull that is when I start chipping edges, ect.

[Adam Stevens2]

I keep seeing mention of stropping but obviously I haven't gotten into that. It sounds extremely simple? Perhaps I should really look into that as an addition to my arsenal. Of course there's the matter of finding a place for it in my junkyard, er workshop.

[Jim Koepke]

One Epiphany of the sharpening threads is the passion folks have developed over the "rituals" followed in their path to sharpness.

There are many paths to achieving a keen edge. It is wise to try all that appeal to you in order to find what works best for you.

Learning to free hand sharpen is an important step. However, not learning free hand sharpening hasn't prevented many from working wood. It just makes sharpening a little inconvenient at times.

A hollow grind is nice for getting "the feel" of the edge when free hand sharpening. My "grinder" is a flat disk type and doesn't leave a hollow grind.

From buying used planes and chisels it seems many former owners of tools relied too much on their grinders and not enough on simple honing with a fine stone. Most of my tools once they are set up do not get returned to the powered abrasion station.

Most of the time my tools do not purposely have a micro bevel. Nothing wrong with them, it is just easier (for me) to not use them.


I keep seeing mention of stropping but obviously I haven't gotten into that. It sounds extremely simple? Perhaps I should really look into that as an addition to my arsenal. Of course there's the matter of finding a place for it in my junkyard, er workshop.

It can take up very little room. My strops are old pieces of leather. When needed they can be set on any hard flat surface.

It is when you start stropping gouges and curved blades that it can start to take up a lot of room.

jtk

[ian maybury]

The big breakthrough for me was recently discovering fine waterstones (initially inspired by David Charlesworth, and with help from e.g. David W and others/old posts here), and how they can bring an edge to a very high polish and state of sharpness.

I'd been hand sharpening since a kid on stock oilstones (in retrospect pretty coarse - there was no tradition of using Arkansas and other very fine stones here) and using standard quality Stanley tools and the like. More recently on diamond plates - and while doing OK there was always an 'is this the best that's possible' itch i somehow never summoned the urge to scratch - to go after a better fix. Possibly because I was inclined to be sceptical of stories about splitting hairs and the like, then because money was tight and waterstones get pricey.

The other big step was discovering high end tools. (mostly Veritas planes & Japanese chisels in my case)

In a funny sort of a way the thing is holistic. It's not so much about a single breakthrough, as a collection of improvements that bounces the whole deal to a new level of performance. Rapidly wearing watersones force taking flattening seriously, and flatness/straightness, good surface finishes plus the precision and the steel in good tools all add up to something greater than the parts.

The other oddity is that having seen what works/what it takes to make it happen i'd probably have no difficulty now upgrading an old plane to get it performing well - wheras back in the day it seemed just to be par for the course that e.g. shavings got stuck under the cap iron and so on. The fixes are not remotely rocket science, but when nobody is doing it it's very tempting to shrug and accept the status quo.

The key to it all is in a sense belief - it enables us to buy into possibility as fact. The web is a big factor too, in that it's taken the information sharing that underpins this to new levels. Back in the day much of this stuff was almost like secrets and had a mystique - only a select few were initiated. Remember all those old coffee table style woodworking books that described stuff in non specific terms - that never set out the nitty gritty/actually spilled the beans? These days pretty much anybody with the patience to read the topic and some basic hand skills can access all the information they need...

[Stewie Simpson]

Hi Jim. You offer very sound advise. Personally I cant remember the last time I used a bench grinder to hollow grind a chisel or plane iron. Flat bevels and freehand sharpening makes much more sense to me.

Stewie;

[Adam Stevens2]

Most of the time my tools do not purposely have a micro bevel. Nothing wrong with them, it is just easier (for me) to not use them.



Jim,

I've been seeing this option crop up a lot in my reading. I'm used to putting a microbevel on my blades, but apparently at some point the microbevel progresses to a point where it's no longer particularly sharp? Apparently my understanding of blade geometry is off because I'm not sure how this happens or at what point. I guess when sharpening a flat bevel you're just giving it a quick polish? I'm also guessing that by doing that you're ever so slowly shortening the chisel by removing metal off the entire face.

[Robert Engel]

Robert,

Would you mind pointing me to the article, just curious.

Just as a comment, I shaved hair off my arm yesterday straight off 80 grit sandpaper on a granite plate, so the chisel was sharp in some spots at least, but the difference (and I knew this) is the edge does not meet on a line, but rather a zig-zag of tiny little edges which will break very quickly effectively becoming dull. So very interested on the article's take on polishing.

Disclaimer, I also normally stop at 8K, and in my experience, if I am not careful on the loaded leather strop I actually dull my edge when polishing there.

PedroGuess I need to rephrase that. What the article said was microscopic examination of the edge showed no benefit in polishing.

I will scan the memory banks where I read that, but I think it was in a ww'ing journal.

[Chris Parks]

I think it needs to be remembered that Paul Sellers did his apprenticeship and earned his living as a tradesman. This would have necessitated trading the time of sharpening against the time needed to get the job done quickly. A person whose hobby is woodworking would not have that issue and could take sharpening as far as he wanted not worrying about the time it took.

[Kent A Bathurst]

I do have a 'green' 220 grit stone - would that be too coarse?

Late in response.......

Oh, yeah - Fer Sure !! That's the problem.

Use the 220 to get it all squared away quickly, then work you way through your stones. You are getting the form straightened out with the 220, then using subsequent stones merely to remove the heavy scratches left by the previous stone, and replace them with smaller scratches from the finer stone........Even the high-mirror polish has scratches - you just need the right equipment to be able to see them. As if you cared.

You would not take a rough-cut chunk of tree, and smooth it out starting with 150 grit sandpaper, right? Same principle.

[Adam Stevens2]

Late in response.......

Oh, yeah - Fer Sure !! That's the problem.

Use the 220 to get it all squared away quickly, then work you way through your stones. You are getting the form straightened out with the 220, then using subsequent stones merely to remove the heavy scratches left by the previous stone, and replace them with smaller scratches from the finer stone........Even the high-mirror polish has scratches - you just need the right equipment to be able to see them. As if you cared.

You would not take a rough-cut chunk of tree, and smooth it out starting with 150 grit sandpaper, right? Same principle.

Don't worry, I wasn't thinking of going to the 220 stone and just leaving it at that, if that's what you were thinking! I've been using up to 6000 grit and that seems to be getting the job done. I did start off with the 1" chisel tonight using the 220 stone and that seemed to flatten out the back pretty quick smart. Still progressing through the finer grits, maybe I can do that before bed...

[ken hatch]

Robert,

Would you mind pointing me to the article, just curious.

Just as a comment, I shaved hair off my arm yesterday straight off 80 grit sandpaper on a granite plate, so the chisel was sharp in some spots at least, but the difference (and I knew this) is the edge does not meet on a line, but rather a zig-zag of tiny little edges which will break very quickly effectively becoming dull. So very interested on the article's take on polishing.

Disclaimer, I also normally stop at 8K, and in my experience, if I am not careful on the loaded leather strop I actually dull my edge when polishing there.

Pedro

Pedro,

As you just demonstrated shaving hair off your arm isn't much of a test of sharpness, nor is the gleam of polish. The best check is to just look at and feel the edge. It also helps to know how much polish or haze you can expect from your stone but whatever if it feels smooth and you get no reflected light lines or bits of reflection off the edge the iron is sharp.

Several months ago David Savage posted electron microscope images of one of his irons sharpened with a "natural" stone and of a iron sharpened with a synthetic water stone. The iron sharpened on the synthetic stone had a high polish and the natural stone sharpened iron only a dull haze. Under extreme magnification is was very clear the iron with the dull haze was much sharper.

I go back and forth between a Shapton 15000 and a Hard Black or Translucent Arkansas as my finishing stone....the Shapton polish will blind you, the Arkansas not so much but both are equally sharp. Folks also go over board on the number of grits they use, unless the edge is damaged two stones are enough, a soft stone to set up the edge and a hard one to finish it. Of course as with all things wood YMMV.

ken

[Andrew Pitonyak]

The Father of a friend showed me a Stanley 5 1/2 plane. The blade was awful so, silly me, I offered to sharpen it for him. I probably spent four hours flattening the back on my stones. I finally gave up on perfect. It took all of a few minutes to have a nice bevel using my Tormek and finishing it from there was trivial. It was new enough that I was worried about how it would work. Took great shavings in a piece of Oak I had on my bench. It was flat sawn with what I thought would be difficult grain.

[Jim Koepke]

Jim,

I've been seeing this option crop up a lot in my reading. I'm used to putting a microbevel on my blades, but apparently at some point the microbevel progresses to a point where it's no longer particularly sharp? Apparently my understanding of blade geometry is off because I'm not sure how this happens or at what point. I guess when sharpening a flat bevel you're just giving it a quick polish? I'm also guessing that by doing that you're ever so slowly shortening the chisel by removing metal off the entire face.

My guess is a lot more metal is removed from the overall length of a chisel or plane iron by taking it to the grinder than removing a few ten thousandths of metal from the bevel on bench stones be they oil or water stones.

Most of the time my "quick polish" is raising a burr on a 4000 stone, cleaning off the burr and polishing the bevel with an 8000 stone and then a few strokes on a leather strop.

The slow shortening of the blade will likely take longer than the rest of my lifetime. A former work associate of mine nearly wasted away a blade by removing a lot of metal at the grinder. Surprisingly, he didn't over heat it.

jtk

[Derek Cohen]

It strikes me that for most this whole area is a non-issue.

For most, hollow grinding a blade removes waste from the centre of the hollow. The subsequent honing removes the same amount of steel as honing on a flat bevel. All a hollow does is remove the unimportant steel from the equation when honing. Honing here removes the same amount of steel as the next method, but takes longer.

For those with a Tormek or a CBN wheel, it is possible to grind to the edge of the blade. The aim is not to grind away the edge, but just to the edge. You can determine this by feeling for the wire edge. Stop grinding when you feel the finest of burrs. In my case I hone directly on the hollow, and the microbevel so created is coplanar with the primary bevel. In other words, no secondary bevel is formed.

The third method is to use a honing guide and add a secondary bevel. This could be done on a flat or hollow grind. The secondary bevel will shorten the blade more than the other two methods.

Even in the latter method, the amount of steel removed - by one experienced - in minimal: what is the size of a wire edge? It is only the inexperienced who creates a secondary bevel that is larger than necessary, and that thereby shortens the blade more.

I appreciate that professional workmen of Yesteryear attempted to preserve the expensive steel because it was a significant part of their overhead. Today, very few professional furnituremakers would use their handtools enough to wear them out, and they are cheap enough for this to be less of a concern (a friend if mine is a high end furnituremaker who is known as a specialist in handtools. I've watched him work many times, and only a small percentage of his work is done with handtools. His LN chisels still have the first hollow grind he put on them several years ago). It is more likely to be the jobsite carpenter who grinds a cheap chisel on a beltsander that will reduce blades to a stub more rapidly. The amateur who does use handtools may care more, but still is unlikely to use up the steel in their lifetime. There may be a few years of wastefulness until they dial it in.

Regards from Perth

Derek

[Graham Haydon]

Adam, it's great to hear you are getting a level of sharpness that will move you to another level.

Derek I'm not sure I follow how a chisel or plane iron gets shorter by applying a secondary bevel over a hollow grind. Would not any method respective of type shorten by the same amount. All any method does is bring the meeting surfaces of the edge back to sharp. One method does not need more more length removed to do so?

I've always thought it best to avoid grinding up to the edge, if you can feel a burr when grinding you are removing more length than any other method.

[Derek Cohen]

... Derek I'm not sure I follow how a chisel or plane iron gets shorter by applying a secondary bevel over a hollow grind. Would not any method respective of type shorten by the same amount. All any method does is bring the meeting surfaces of the edge back to sharp. One method does not need more more length removed to do so?

I've always thought it best to avoid grinding up to the edge, if you can feel a burr when grinding you are removing more length than any other method.

Hi Graham

A secondary bevel, by definition, is a bevel that is ground or honed higher than the primary bevel. A micro bevel is simply a small bevel, whether secondary or coplanar.

A coplanar bevel is created when a micro bevel is honed directly on the face of a hollow grind. This means that the front and rear edges of the hone are aligned.

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Bevel-grinding1_zpsuif5d4ca.jpg

As you will see in the picture, although not to scale or angle, a secondary bevel will always remove more steel than the equivalent angle coplanar bevel (the same applies to honing a flat bevel).

About grinding a wire edge - note that I said that the only applies to a Tormek and a CBN wheel (because they will not overheat the thin steel). The aim of the ideal grind is to get as close to the edge of the blade as possible. I stop when I can feel the faintest wire developing. This is a wire about the same as created on a 1000 grit waterstone at most. This is still less steel removed than a secondary bevel. The advantage of grinding this close is that the amount of honing is reduced, and the microbevel formed is smaller. (Note also that the edge is not weakened by grinding this far - I have never experienced an edge breaking down because of this, and I do work with some really hard woods).

One more thing: as you hone the secondary bevel, it is common practice to raise the angle sightly. This shortens the blade (imperceptibly, but still so). Honing on the coplanar bevel (and flat bevel) removes less steel from the length.

Regards from Perth

Derek

[Lee Schierer]

I discovered the scary sharp method a number of years ago and was amazed at the improvement in cutting ability of my chisels and planes. I recently sharpened a spoke shave iron in about 20 minutes which included removing several minor chips.

[Graham Haydon]

Cheers Derek,

I think I must be going bonkers because I can't make it out. The angle of the micro bevel on both the hollow and the secondary are the same no? You would need to remove the same amount of blade length to remove wear and get a sharp edge? The diagram shows a secondary bevel honed more that it needed to be from a fresh grind and honed steeply. The hollow grind diagrams shows a lower honing angle and less removed. It don't think it's comparing apples with apples. But like I said I most likely am to thick to get it.

[Jim Koepke]

Cheers Derek,

I think I must be going bonkers because I can't make it out. The angle of the micro bevel on both the hollow and the secondary are the same no? You would need to remove the same amount of blade length to remove wear and get a sharp edge? The diagram shows a secondary bevel honed more that it needed to be from a fresh grind and honed steeply. The hollow grind diagrams shows a lower honing angle and less removed. It don't think it's comparing apples with apples. But like I said I most likely am to thick to get it.

If one has a sharp primary bevel and then hones on a secondary bevel, some metal has been removed, thus more shortening of the total length.

We are talking thousandths of an inch and semantics.

Because of the area of a single bevel is larger than the area of a secondary bevel, more metal is removed when honing on a single bevel. The difference of the length between the two honing processes may be zero. It is when the secondary bevel is reground that more metal may have to be removed eating up what wasn't removed in the past.

If you are not totally confused, you just don't understand the situation. -Edward Murrow

jtk

[Derek Cohen]

OK Haydon .. have you had your meds today? A soothing hot bath? :) :)

I think I see what may be confusing you. I did not include it as it was too obvious. "Obviously" not! :)

The primary bevel for the hollow grind is higher than the flat grind-plus-secondary to achieve the same cutting angles. For example, the primary for the hollow may be at 30 degrees, while the flat grind may be 25 degrees and the secondary on it at 30 degrees.

Adding that secondary will shorten the blade.

Regards from Perth

Derek

[Steve Voigt]

OK Haydon .. have you had your meds today? A soothing hot bath? :) :)

I think I see what may be confusing you. I did not include it as it was too obvious. "Obviously" not! :)

The primary bevel for the hollow grind is higher than the flat grind-plus-secondary to achieve the same cutting angles. For example, the primary for the hollow may be at 30 degrees, while the flat grind may be 25 degrees and the secondary on it at 30 degrees.

Adding that secondary will shorten the blade.

Regards from Perth

Derek

I don't think Graham is the one who is confused. Your argument is a little like Xeno's paradoxes, where one concludes that the arrow never reaches its target. :)

As he said, we need to work back a certain distance from the cutting edge, as measured along the back of the blade, to remove damage (or wear), whether it's damage from the grinding wheel or from work. Let's say that distance is .001". We then need to hone until the blade has been effectively shortened by .001. It doesn't matter whether we balance on the hollow or lift the blade off the hollow.
Since balancing on the hollow more closely approximates the initial grind angle, it will take more strokes to remove the wear than if you lift the blade. Perhaps that is what you really mean, that given an equivalent number of strokes, balancing on the hollow will remove less length? But of course we don't use an equivalent number of strokes. Balancing on the hollow requires significantly more strokes than lifting the blade does (I'm not saying one is better, just that one requires fewer strokes).

One other point. Both of the honed bevels in your diagram are "secondary" bevels. In your first diagram, if you draw a tangent line to the arc, right at the cutting edge, the slope is shallower than the honed bevel. It doesn't matter whether the honed bevel is "co-planar," it's still steeper than the ground bevel, and therefore meets your definition of a secondary bevel. Lifting the blade just produces a slightly steeper secondary method than yours.

[Derek Cohen]

Sorry Steve, but we are not on the same path this time. I think it may be terminology (some refer to a secondary as a micro, and vice versa - I do not).

Firstly, a coplanar grind/hone simply means "in a straight line", or "in the same plane". Therefore, when you hone directly on the surface, a 30 degree primary bevel produces a 30 degree cutting edge. There is no secondary bevel. Get the hollow close to the front of the blade, and you will have a coplanar micro (small) bevel.

No one has mentioned which method requires more or less strokes. You introduced that. In this light, you suggested lifting the wear, which would create a secondary bevel. I did not suggest this. I am referring only to honing on the hollow (which creates a coplanar bevel face). As I noted before, this is essentially the same as honing on a flat bevel, but with a much reduced amount of steel to hone. Only in this regard do I mention speed, which is faster with the hollow vs the flat. I am not including the secondary hone here, which can be as fast or even faster to do, but not as easy to re-do.

Regards from Perth

Derek

[Brian Holcombe]

Assuming we're talking about putting the same angle on the end of the blade I also do not see how one approach winds up effecting the length of the blade more than another. I'm not discounting either approach as I quite like sharpening hollow ground blades freehand on the stones (HNT gordon provides them hollow ground), but I have drawn one approach overlaid by the other approach, to scale, and do not see how one is different from the other.

[Graham Haydon]

Not sure about meds Derek but I did have two glasses of scrumpy last night :)

As Steve said no matter the method we need to remove the wear/damage to refresh the edge. That wear is a fixed point, a distance that can not be changed and a certain amount of steel must be removed regardless of method we find most effective.

Perhaps the image shows what I mean? No matter the method, in theory we must remove the red zone. I don't see how the hollow grind changes this.

312289

[Ted Friesen]

Well I'm with you. Being relatively new to woodworking I've often heard or read that I will KNOW when a tool needs to be sharpened--but when you're new that doesn't really work--until recently working on a project I thought "Hey this chisel needs sharpening". That's an epiphany!

I use Shapton stones and just a few strokes on the 8000 stone on the secondary bevel had the chisel cutting very well again. A few more of these aha moments and I may be able to begin calling myself a woodworker.

[Derek Cohen]

Hi Graham (and Steve)

Not sure what scrimpy is, or even if I should volunteer to try it ... but we do have some great beers in Perth. I have a couple on ice waiting for you two.

Anyway, it seems to me that nothing has changed (!). The wear is a common factor, and has to be removed from both chisel sharpening formats.

I am not arguing which method requires more or less steel to be removed - the original question was which shortens the blade most. I need a better explanation. Until then we are left with a secondary bevel which grinds at an angle to the primary bevel, which shortens it.

Frankly, I am now as confused as any, and will go and think some more over a beer. :)

Regards from Perth

Derek

[Graham Haydon]

Always a good idea! And Scrumpy (scrimpy! that's just offensive :)) http://en.wikipedia.org/wiki/Scrumpy

[Stewie Simpson]

Always a good idea! And Scrumpy (scrimpy! that's just offensive :)) http://en.wikipedia.org/wiki/Scrumpy

https://www.danmurphys.com.au/product/DM_366104/westons-old-rosie-scrumpy-flagon-2l Nice brew.

[Warren Mickley]

It strikes me that for most this whole area is a non-issue.

I appreciate that professional workmen of Yesteryear attempted to preserve the expensive steel because it was a significant part of their overhead. Today, very few professional furnituremakers would use their handtools enough to wear them out, and they are cheap enough for this to be less of a concern (a friend if mine is a high end furnituremaker who is known as a specialist in handtools. I've watched him work many times, and only a small percentage of his work is done with handtools. His LN chisels still have the first hollow grind he put on them several years ago). It is more likely to be the jobsite carpenter who grinds a cheap chisel on a beltsander that will reduce blades to a stub more rapidly. The amateur who does use handtools may care more, but still is unlikely to use up the steel in their lifetime. There may be a few years of wastefulness until they dial it in.

Derek

A friend is a high end furniture maker, known as a specialist in handtools? And he hardly ever sharpens his chisels? You are straining credulity.

I have never seen a Tormek or a sharpening jig in a professional shop. I am sure there are some, but the idea that they are necessary is far fetched. The "workmen of Yesteryear" tended to use grindstones that were in the 20 inch diameter range, not much of a hollow grind. Try it sometime.

[Derek Cohen]

A friend is a high end furniture maker, known as a specialist in handtools? And he hardly ever sharpens his chisels? You are straining credulity.

Warren, I did not say that he hardly ever sharpens his chisels. I wrote that he has not re-ground them since the first grind.

Why do you persist in misinterpreting what I write?


The "workmen of Yesteryear" tended to use grindstones that were in the 20 inch diameter range, not much of a hollow grind. Try it sometime.

Why?

Regards from Perth

Derek

[Graham Haydon]

Stewie, mine is the Westons Scrumpy Cloudy Cider. One of my friends has a family that makes it "the old way". I only feature in the first photo http://www.foto8.com/live/the-cidermen/. It was a terrific bit of scrumpy!

I wish we still had our big grindstone, it made way for more machines and became a feature at my Grandparents house. Replaced by........a tormek! :-)

[Graham Haydon]

Derek, I think I may have got it.

Firstly this is your favorite method so it has to be based on your method. So in your example grinding means raising a burr before honing again. On the first hone after this "burr grind" you would indeed use little more length on the tool on the first hone only if you lifted for a secondary. After the first hone both hollow hone and secondary then remove the same amount of length as they have to overcome wear/damage

I think because I don't grind to the edge this had me confused. And for those not doing a "burr grind" my original point of all methods remove the same still stands. Do I have it or am I still missing it!

[Adam Stevens2]

I may have started something I didn't intend to, as I was more merely curious about the difference between flattening the entire bevel vs creating a microbevel. I didn't mean to imply that one procedure or another would have a significant impact on the wear of the tool. I'm just trying to figure out what is going to be the optimal way to hone without spending too much time on it.

I may have mentioned that I don't have a grinder and don't fancy myself using one at the moment, so hollow grinding is something of a moot point for me right now, though it is good to know that it is an option.

[Graham Haydon]

Adam, it's just a good natured discussion, truly it is :). Most importantly you seem to be doing great and getting good results, keep doing it!

[Adam Stevens2]

My guess is a lot more metal is removed from the overall length of a chisel or plane iron by taking it to the grinder than removing a few ten thousandths of metal from the bevel on bench stones be they oil or water stones.

Most of the time my "quick polish" is raising a burr on a 4000 stone, cleaning off the burr and polishing the bevel with an 8000 stone and then a few strokes on a leather strop.

The slow shortening of the blade will likely take longer than the rest of my lifetime. A former work associate of mine nearly wasted away a blade by removing a lot of metal at the grinder. Surprisingly, he didn't over heat it.

jtk

Jim,

that process sounds reasonable and simple. I suppose it's the initial establishment of the primary bevel that's a little more time consuming, but once that's done it's just a matter of honing the bevel briefly as you describe. Maybe worth a try on the 1/2" chisel that hasn't seen a stone yet and see how that goes.

[Steve Voigt]

mine is the Westons Scrumpy Cloudy Cider. One of my friends has a family that makes it "the old way". I only feature in the first photo http://www.foto8.com/live/the-cidermen/. It was a terrific bit of scrumpy!


So I was outside splitting some sections of beech log that a neighbor brought by. I walk into the house (I am not making this up) and my wife hands me a glass of home-brewed hard cider…she's the brewer in the family. Then I sit down to read your posts, and it's all about cider. I think it was a providential sign that I should have a second glass. :D
Scrumpy is a great name! Enjoy!

[Steve Voigt]

Sorry Steve, but we are not on the same path this time. I think it may be terminology (some refer to a secondary as a micro, and vice versa - I do not).

Firstly, a coplanar grind/hone simply means "in a straight line", or "in the same plane". Therefore, when you hone directly on the surface, a 30 degree primary bevel produces a 30 degree cutting edge. There is no secondary bevel. Get the hollow close to the front of the blade, and you will have a coplanar micro (small) bevel.

No one has mentioned which method requires more or less strokes. You introduced that. In this light, you suggested lifting the wear, which would create a secondary bevel. I did not suggest this. I am referring only to honing on the hollow (which creates a coplanar bevel face). As I noted before, this is essentially the same as honing on a flat bevel, but with a much reduced amount of steel to hone. Only in this regard do I mention speed, which is faster with the hollow vs the flat. I am not including the secondary hone here, which can be as fast or even faster to do, but not as easy to re-do.

Regards from Perth

Derek

Derek, I'm more than happy to drop this, but just a couple clarifications first.

I know what coplanar means…I used to teach math, you know. :) But you are missing my point. Your hollow grind (in your first diagram above) is an arc, and so by definition does not have a fixed angle. If it did, we'd have no use for calculus! Look at your diagram and draw a tangent line to the arc, right in the center of the arc. That line is parallel to to your "coplanar bevel," and so has the same angle. But if you draw the tangent line at the bottom of the arc, where the cutting edge actually is, that tangent line has a considerably shallower angle than your coplanar bevel. Conversely, at the top of the arc, the tangent line is steeper than your coplanar bevel. There is no such thing as "get the hollow close to the front"--the hollow is always in the center, it can't be any place else, unless you are not grinding away all of the old bevel. No matter how steep or shallow your hollow grind is, when you balance that hollow on your stone and hone, you will steepen the angle at the cutting edge, and reduce the angle at the heel of the bevel. That is why your coplanar bevel is in fact a secondary bevel.

Also, just to be clear, the reason I brought up lifting the back of the blade is that it was implied in your second diagram. I thought that was your intent, that the first diagram shows honing by balancing on the hollow, while your second diagram shows registering on a flat (could've been a hollow also) and then lifting the back of the blade.

This is making my head hurt. I'd have that beer now, but I already drank some of Graham's cider, er, scrumpy. :p

[Adam Stevens2]

Adam, it's just a good natured discussion, truly it is :). Most importantly you seem to be doing great and getting good results, keep doing it!

Thanks Graham! I have a Hock kit plane that took me forever to finally get in working order, right up until yesterday (filing the mouth open was tedious!). Just now I decided to "let's see how this goes as a smoother", put a slight camber on the blade and it's cutting through red oak scrap like a hot knife through butter without leaving any track marks that I can see. So I'm very glad to feel like I'm "getting it" now.

[Graham Haydon]

Excellent Adam, life feel good when it comes together. What you can be sure of just when it feels like it's coming together along comes a curve ball!

[Derek Cohen]

I think I have figured it out. Steve, I'm sorry to say that I must disagree with your reasoning (more likely I do not understand your reasoning) - that this is more about geometry than calculus .. and the answer becomes apparent when a missing element is added in.

Firstly the bottom line: the hollow grind and the secondary bevel remove the same amount of metal. There is a provisor, however. I will come back to this part (keep you in suspense! :) ).

What was missing from our computations? Well, the hollow grind was on a bevel face of 30 degrees, and honing would take place on the hollow, with the hollow acting as a jig for the hone. The secondary bevel of 30 degrees would take place on a bevel face of 25 degrees. What was missing is that in both situations the honing is at 30 degrees. One imagines that the 30 degree secondary bevel is removing extra steel, but it is not - it is only removing the steel that would have been ground away if the primary bevel was 30 degrees ...

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Bevel-wasted2_zpsr64zri5r.jpg

The orange section in the second figure represents the area of steel ground away from the 25 degree primary bevel that would be present if it were ground to 30 degrees.

The red lines represent the first hone. This should remove the same amount of steel from both blades as long as the 30 degree angle is maintained.

The blue lines represent the second hone. Again, this should remove the same amount of steel from both blades as long as the 30 degree angle is maintained.

Here is the provisor: freehand honing on the hollow grind essentially ensures that the bevel angle is maintained. However, this is not the case for the secondary bevel. Only a honing guide will ensure the angle is kept. When freehanding there is the tendency to increase the angle slightly. Eventually this will remove more steel this way, plus a later regrind to re-establish the angle will use up still more steel. By contrast, removing waste from the hollow does not alter the bevel angle, and ensures that the same amount of steel continues to be removed as always.

A hollow like this will last a long time ...

http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp_html_71b2c2d0.jpg


Regards from Perth

Derek

[Graham Haydon]

Thanks for the diagrams Derek. Diagram 2 shows the black line of the grind angle projecting beyond the red first hone. If when we grind we leave in a sliver of hone both methods changes the length by the same amount. I think these diagrams only work if you grind to a burr so to speak?

[Derek Cohen]

Hi Graham

Don't take the diagrams too literally - they are just rough drawings for illustration. Perhaps someone might redo them using SketchUp. That would be more accurate.

Still the answer is there, I believe. Time for a Scrumpy? :)

Regards from Perth

Derek

[Robert Engel]

Let me be the voice of reason:

Hard cider, axes and other thing related to sharp tools do not mix. LOL

Beyond the nuances and uber details, guys, I like hollow grinding because I usually touch up the edges freehand and I can rock the tool to find the "primary" bevel, then lift up slightly to hone the "secondary" bevel. This, to me, is the biggest advantage of hollow grinding.

Adam - trust me, you WILL want to get a grinder and try this technique before its over with.

[Noah Wagener]

A hollow grind is a secondary bevel. Unless you work right off the wheel or have a round hone to match the wheel. Chisel life is the same for both methods even if you are raising the secondary bevel more with sucessive honings. Unless you keep honing after you have raised the wire edge. Than yes, 10 strokes at 35 degress will shorten the tool more than the same at 30 degrees.

[Stewie Simpson]

Hi Robert. How close to the cutting edge would you recommend Adam hollow grind too.

Stewie;

[Derek Cohen]

A hollow grind is a secondary bevel. Unless you work right off the wheel or have a round hone to match the wheel. Chisel life is the same for both methods even if you are raising the secondary bevel more with sucessive honings. Unless you keep honing after you have raised the wire edge. Than yes, 10 strokes at 35 degress will shorten the tool more than the same at 30 degrees.

Noah, I don't follow your reasoning here. You appear to contradict yourself.

Regards from Perth

Derek

[Noah Wagener]

You would normally use less strokes at the higher angle and stop when it is sharp. You could raise your bevel to 50 degrees and still not get anymore wear on the back of the chisel than 20 degrees. You would just stop a lot sooner, when the wear has been removed as Mr. Haydon pointed out. If you kept on honing after the rounded edge has been removed,
Than yes, 10 strokes at 35 degress will shorten the tool more than the same at 30 degrees.

[Noah Wagener]

I suppose in the real world you can not stop honing at the exact optimum time and may shorten the life more if you use the secondary bevel method without being able to keep a consistent angle.

[Pat Barry]

It seems the real epiphany in this story is that there are many ways to get a sharp edge on a tool, nearly as many ways as there are folks doing the sharpening it seems, and no doubt everyone is getting a sharp edge and also that getting a sharp edge can be accomplished without a basic understanding of physics.

[John Schtrumpf]

I suppose in the real world you can not stop honing at the exact optimum time and may shorten the life more if you use the secondary bevel method without being able to keep a consistent angle.
Finally, some common sense. Along with, the method that sharpens the quickest, has the most potential to shorten the length the quickest.

[Graham Haydon]

It's always scrumpy time Derek :)

[Brian Holcombe]

But.....Sometimes it's whisky time.

[Warren Mickley]

It seems the real epiphany in this story is that there are many ways to get a sharp edge on a tool, nearly as many ways as there are folks doing the sharpening it seems, and no doubt everyone is getting a sharp edge and also that getting a sharp edge can be accomplished without a basic understanding of physics.

I am baffled by this remark. Are you claiming that workers with real depth of experience, real discernment, and real understanding should not bother speaking up? Let the blind lead the blind?

[Pat Barry]

I am baffled by this remark. Are you claiming that workers with real depth of experience, real discernment, and real understanding should not bother speaking up? Let the blind lead the blind?
Talk about baffled, how would you get what you said from what I said? What I said was about as simple as you can get. By the way, by all means, speak up if you have something to offer.
So far you have said:
A friend is a high end furniture maker, known as a specialist in handtools? And he hardly ever sharpens his chisels? You are straining credulity.
I have never seen a Tormek or a sharpening jig in a professional shop. I am sure there are some, but the idea that they are necessary is far fetched. The "workmen of Yesteryear" tended to use grindstones that were in the 20 inch diameter range, not much of a hollow grind. Try it sometime.

Are we all supposed to go get 20 inch grindstones?

[Warren Mickley]

Yes, you should certainly get a 20 inch grindstone and try it if you want to feign expertise on the "workmen of Yesteryear".

I am sorry you did not understand my remarks.

[Jim Koepke]

no doubt everyone is getting a sharp edge and also that getting a sharp edge can be accomplished without a basic understanding of physics.

If everyone was getting a sharp edge we wouldn't have a thread about someone all of a sudden discovering a new level of sharpness.

Yes, people can accomplish sharpness without a basic understanding of physics.

Just like people without any knowledge of electricity can turn on their TV. People drive cars all the time without knowing anything about the basics of mechanics. People walk to the sink and get a drink of water without any understanding of plumbing.

When the day comes that the blade isn't getting sharp, the TV isn't working, the car is stopped by the side of the road or the water doesn't run, it is beneficial to have some knowledge so one's wallet doesn't get drained by those who took the time to understand some of the basics of various things around us.

jtk

[Pat Barry]

My point was there are a LOT of ways to get a sharp edge. Think about it: Waterstones, oilstones, diamond paste, granite surface plates, glass, sandpaper, scary sharp, honing guides, grinding wheels, high speed grinders, belt sanders, CBN wheels, white wheels, Tormeks, ceramic plates, even 20 inch grinding wheels for some of the old timers. Everyone has their own method and sequence of work and its really just whatever works for each guy out there. I am sure you have your way Jim and it works fine for you. It probably isn't the same as what Warren does and for the most part it doesn't matter.

[Robert Engel]

Hi Robert. How close to the cutting edge would you recommend Adam hollow grind too.

Stewie;
It really depends on your grinding wheel.

I use a pretty fine wheel I think its 150 grit.
If I'm careful I can go right to the edge, but I mean you have to be careful.
You have to be patient and not pass the blade to slowly and keep the water close.
I feel the blade after every couple passes for heat the finer the wheel the more heat you get.

You don't have to go right to the edge I think if you can get at least within 1/16 the problem is you will have more honing because you're secondary bevel will be longer.

[Pat Barry]

Here are a few of the things we have learned from this thread:
Primary bevel (30 degree, 25 degree, etc) , secondary bevel (a bit higher angle than the primary), back bevel, no back bevel, micro bevel, coplanar bevel, secondary micro bevel, coplanar secondary micro bevel, green stropping gunk on MDF, green stropping gunk on leather, stropping on leather, don't strop too much, don't polish too much, use tormek grinder, flat grinder, 6 inch round wheel grinder, 20 inch round wheel grinder (like Warren), don't let the temperature of the edge get too hot, dip it in water, test the heat with your thumb, use CBN wheels, white wheels, gray wheels, hard felt wheels, belt grinder, belt sander, ruler trick, sandpaper on granite, sandpaper on glass, scary sharp, hollow bevel, flat bevel, back bevel, free hand polish, honing guides, DMT stones, shpton stones, waterstones, oilstones, japanese stones, translucent stones, arkansas stones, hard black stones, Seller's method, Cosman's method, Weaver's method, everyone else's methods, lift up a little for that secondary micro bevel. Remove the wear, refresh the edge. Oh yeah, remember to always flatten your stones before / after each use (a whole 'nother discussion). I can't even count how many comments were on the lines of 'my head hurts', or now I need a 'scrumpy'.

Overall its been interesting, very much enlightening as to the world of possibilities, not much of teaching guide though. Like I said, to each his own.

[Robert Engel]

Pat that's funny.

And all its about is two edges meeting in as sharp a point as possible.

[Ralph Juarros]

Sometimes language just seems to confuse communication with complication, and the result is a compilation of misinformation..

[bridger berdel]

But.... but.... sharpness isn't about two faces meeting in an abstractly perfect union.... it's about the ability to cut!

[Steve Bates]

Stewie, I'll try to find some of https://www.danmurphys.com.au/produc...umpy-flagon-2l (https://www.danmurphys.com.au/product/DM_366104/westons-old-rosie-scrumpy-flagon-2l) on this side of the pond. I really like your Sheaf Stout but I can't find it here any more.

Thanks for the information.

[Jim Koepke]

I really like your Sheaf Stout but I can't find it here

I haven't seen that in years.

One that I do like is Samuel Smith's Oatmeal Stout.

There is also Anderson Valley Barney Flats Oatmeal Stout.
It's not just shy sluggin’ gorms neemer. (It’s not just for breakfast anymore.)

http://www.andersonvalleymuseum.org/boont.html

jtk

[Adam Stevens2]

Bumping to mention that I received the three-stone Sigma Power set from Stuart at Tools from Japan today. I got an unsharpened narex bench chisel to hair-shaving sharpness in the space of about three minutes. Bit of a revelation compared to my old set of King stones! I'm kind of excited...

[Jeffrey Martel]

Bumping to mention that I received the three-stone Sigma Power set from Stuart at Tools from Japan today. I got an unsharpened narex bench chisel to hair-shaving sharpness in the space of about three minutes. Bit of a revelation compared to my old set of King stones! I'm kind of excited...

I ordered the same set just under 2 weeks ago. Been anxiously waiting for it to arrive. The long lead time is definitely something to consider when buying from Japan.