What do we mean when we say scary sharp? When I get a new plane blade or chisel from the manufacturer, if you run your finger over it just a little you’d get a really nice cut. When I sharpen I go through the grits, hard arkansas slip stones to remove the burr, strop with yellow stone honing compound and I get a very nice sharp edge, but not that sharpness like I describe from the factory. I will sometimes use sandpaper(600,800,1200) or a 600/1200 diamond plate to sharpen. So what do you sharpening guru’s say about this? Thanks
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Replies
Mosf of what you mention can work. Just my opinion; lose the slipstones and the strop for straight edges like planes. They do have a place for curved blades like carving tools.
IMHO, Scary Sharp is just a term that someone started a long time to describe edges that are about as sharp as is possible to make them. I think, in the beginning, it was in reference to the sandpaper on glass method, but there are lots of methods to do it.
In particular, I think whoever coined the term wanted folks to think that his method was superior to previous methods.
There are lots of ways to sharpen; you are doing two or three. If done properly, your edges will be actually sharper for planing and chiseling than the factory edge, unless they are from one of the very premium makers.
An edge looked at carefully looks like a saw-tooth. Whatever abrasive you use leaves scratches. The factories typically use a surface grinder which leaves pretty large scratches. If you run your finger tip along the edge, the saw-tooth pattern cuts you easily. But the edge is not particularly suitable for quality woodworking, as it leaves a poor surface and dulls quickly. With coarse scratches, there is very little metal at the edge. The finer the scratches, the finer the teeth of the edge, and the more metal there is at the edge. Hence the longer the edge stays sharp.
I usually check for sharpness by trying to plane or chisel my thumbnail. Pushing the blade away from the flesh of my thumb. If not sharp, the blade will skate over the nail.
There are tools, such as scissors and shears, that work better with a coarser scratch pattern perpendicular to the length of the edge. The scratches catch the material being cut and keep it from sliding out of the scissors as the two edges close the triangular opening.
If you feel that your edges aren't sharp, check to make sure you are not increasing the effective cutting angle right at the tip by rounding over the edge. I use a honing guide to keep a consistent angle for all the stones. I use a medium-coarse diamond stone, a medium Norton, and a hard Arkansas, plus stropping on leather with rouge compound. Others do different things. I got started with this set-up almost 50 years ago and haven't felt motivated to spend a lot of money on some new system.
Looks like Bob Van Dyke coined the term and methodology..
Sharpening: The Scary Sharp Method
A lesson in an effective, inexpensive way to put an edge on chisels and plane irons, in part one of this 8-part series answering your questions about sharpening. Bob Van Dyke #198–May/June 2008 Issue
https://www.finewoodworking.com/project-guides/hand-tools/sharpening-the-scary-sharp-method
They were using the term a couple of decades before that article. It was definitely the sandpaper on glass people that started it.
Sharp enough is relative. Relative to what you are doing, your expectations, level of skill, time, tools and resources.
If a chisel skids across a finger nail it's blunt. If it bites it's sharp enough for almost any use, it it will shave hairs off your arm easily, it's perfect.
Most of the time, I'm not using tools at the last level because they simply don't keep it long enough.
How to get there is a challenge - for carving gouges and knives, all I use is a strop and polishing compound, though I'm new to that dark art.
For almost everything else, I use a Tormek.
By the time I'd worked through all the other methods, it would have been cheaper to start with that!
It provides a truly razor sharp edge effortlessly. The only downsides are cost and it takes a very long time to re-shape tools (though there is a set of very expensive diamond wheels available which should be faster) - by a very long time, it took me about 4 hours to fix up an otherwise fairly useful skew chisel. It's now absolutely perfect, and will shave hairs off my arm easily and it takes only moments to re-grind it back to perfection now the hard yards are done.
Many folks feel that water stones give the best edge, better than Arkansas stones and better than diamond stones. It's the slurry that develops that gives it the edge, so to speak, over other methods.
That said I get just as good results with less hassle using a Tormek. The Tormek was so easy to use and so much fun that I did all my edge tools and turning tools in an afternoon. As someone mentioned, you don't want to use a Tormek for changing the profile of an edge or gouge or whatever--it takes for ever. So it's good to have a regular grinder around too.
I'm not a strop fan, although I've read articles touting it's virtue and many members swear by it, I'm just not one of them. In my 45+ years of woodworking I've tried just about every sharpening method out there and will say that, while many methods can give a serviceable edge, I do have a few preferences.
First and foremost use a quality jig, for my first 25 years I sharpened freehand and thought I was getting my tools sharp, until I tried a jig and it opened my eyes. The small inconvenience is more than offset by the quality of the edge.
I used water stones probably for 30 years and achieved great edges with them, but not all waterstones are created equal I've used inexpensive stones like King and Norton and even a few no-name ones off of Amazon and definitely feel that the premium stones are worth the money. Another aspect of waterstones is that some are better than others at sharpening some of the harder premium steels that the best tools use. So choose wisely.
While I use diamond plates for coarse work and sharpening things like scrapers I don't like them in even the finest grits for my edge tools. For my chisels and plane blades I am currently using lapping paper, not sandpaper, on plate glass. I made the switch because my current shop has no running water or sink and I got tired of the mess of waterstones. I will say that I could not be happier with the results and wonder why I ever invested thousands into all the different sharpening systems I have used over the years. I will also say if you are only sharpening to 1200 you are ending where I often begin if I'm just touching up an edge. I believe in the double rule each successive grit is roughly double the previous one. 1000 grit is followed by 2000 which is followed by 4000 and so on all the way through at least 10,000 grit. Sharpening is nothing more than removing scratches at a consistent angle. Deep scratches weaken your edge and can lead to chipping and premature edge failure. I defy anyone who says that a 10,000 grit stone can remove the scratches left by a 1200 grit stone. Will it make an edge sharp, probably, but it will be weaker and need to be sharpened more frequently than an edge produced by going through the progressions I follow.
Here is the original Scary Sharp article by Steve LaMantia in 1995.
http://www.inthewoodshop.com/WoodworkTechniques/ScarySharp.html
Regards from Perth
Derek
I miss the rec.
I have not offered sharping advice to the OP as he/she appears to have disappeared. Also, I hate sharpening threads as they just end up with a great many opinions - because everyone has one and every right to do so. This is a discussion, after all. I can only offer what works for me.
I have tried just about every system under the sun for about 3 decades, and what I use now has been unchanged for a decade. I build furniture using very hard and interlocked West Australian wood, and sharp (and staying sharp) is important to me.
Notes:
1. No manufacturer sends out a blade that is sharpened to anything more than 4000 grit at best (information from Veritas). If you cannot get an edge better than this, then you are doing something wrong.
2. Use whatever media you prefer. They can all get you there. Some just do this more efficiently than others. There are always pros and cons: sharpen faster and coarser; sharpen finer and slower. For example, diamond stones are generally used to 1200 grit. That is a coarse stone. It gets you there fast, but I cannot stop there. That is where my sharpening starts!
3. Where does sharpening end? 8000 grit? 12000 grit? Frankly, as you get into the higher grits (which ARE better), it takes very little extra time to do so, so why miss out? The slowest stone is the coarsest stone if you are grinding a primary bevel. As you go up in grits, so less work is needed as the bevel is now flat. My three honing stones are a 1000 Pro Shapton, 6000 Sigma, and 13000 Sigma.
4. Preparing the primary bevel is the most important step in my experience. Get the bevel square and at the angle you want. All the polishing stones are too fine to make any corrections. I hollow grind the primary bevel on a 8" half-speed bench grinder with either a 80- or 180 grit CBN wheel. This system is here: http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.html
5. Whether one hones with a guide or freehand, the most important factor is that every stone/media creates a wire edge. This tells you that you have honed across the bevel to the back of the blade. If you do not achieve this, all you are doing is polishing the middle section of the bevel. The bevel/blade is not being sharpened.
6. If you are using modern, thick plane blades - especially those with composite steels, such as A2 and PM-V11 - you will be wasting energy trying to hone the full bevel face. You have to "trick" the thick blade into believing it is a thin blade :). You do this with a micro bevel. In my case, I hollow grind right up to the edge of the bevel. This reduces all the steel to a fraction. Then I freehand on the hollow (with bevel down plane blades and chisels). That creates a coplanar micro bevel. For bevel up plane blades, I use a honing guide to obtain a secondary micro bevel at the angle I want.
I could write a whole lot more, but I can already see many eyes glazing over. You are welcome to visit my website: http://www.inthewoodshop.com/index.html
Regards from Perth
Derek
The OP is asking why he doesn't get the same "sharpness" when he uses his method as what he gets from a factory edge.
Not where did the term scary sharp come from
Original post:….. What do we mean when we say scary sharp…
Yes, followed by
"When I sharpen I go through the grits, hard arkansas slip stones to remove the burr, strop with yellow stone honing compound and I get a very nice sharp edge, but not that sharpness like I describe from the factory. I will sometimes use sandpaper(600,800,1200) or a 600/1200 diamond plate to sharpen. So what do you sharpening guru’s say about this?"
Scary sharp is just a catchy name someone thought would be good for their particular method, not a scientific description of how sharp something actually is
OP's method is just fine, it may not be the official or even unofficial "scary-sharp" method but it doesn't matter.
Maybe the OP can try tweaking his methods a bit to achieve the factory sharp edge he's looking for but what he described is sound.
All methods and mediums will get you a sharp edge. Mostly it just requires sticking to one method to get good at it. I used diamond stones and got good edges. When they "wore out" after 7 years of use, I switched to Japanese waterstones and they work as well. I can't tell the difference between one method vs. the other. Just practice and stick with a method (you already spend the money) and you will get there. I personally think a honing guide helps when you are first starting but you don't need one.
Personally, I have yet to see any blade/chisel for any manufacturer be as sharp as I can do at home. And I've tried tools from Lee Valley and Lie Nielsen.
Over the years, I've tried most sharpening systems- oil stones, sandpaper, diamond, even Tormek. For the last 15-20 years, I've been using the Shapton Professional stones. I like them a lot. I have the 1,000g., 5,ooog., 8,000g., and 12,000g. stones. The 8K stone leaves a plenty sharp enough edge for all but the most fussy wood.
Yup. I've never gotten a plane or chisel ready-to-go-sharp. Lapped flat, yes. But not honed.
If they can't get a blade from Lie Nielsen or Veritas sharper than how it came in the mail, they really need to work on their sharpening.
I have diamond stones in 3 grits, 300, 600 and 100. I have shaptons in 4000, 8000 and 1600. I could probably do w/o the 4000. (I also use the 300 or 600 to flatten the shaptons (not perfect but good enough)). I also have some float glass and sandpaper that I use to flatten the back of new tools. The stones work great for me but only because I also have the Lie-Nielsen honing guide and I made a stop block (I happened to use the L-N's plan) to enure consistent angles. I resisted Bob's advice on each but eventually gave in and I'm glad I did. I'd say I'm 90 % + more efficient than I used to be. I had the Veritas honing guide but it was a challenge to use esp to put a micro bevel on a tool. Don't skimp on the honing tool. I don't do this enough to get good at free hand sharpening. My tools shave hair so that's as scary as I need. Watch Bob's other vids too.
Not a guru by any means. I believe any abrasive of the right grits can get tools sharp enough. I personally use diamond due to lack of water in the shop amd durability.
Inability to get sharp is more about process. Do you use a honing guide? That would be my recommendation. It removes a lot of skill from sharpening, skill that that takes time and regular use to develop and maintain. I don't get enough shop time to be good enough to hand sharpen, I let a honing guide make up for the lack of skill so I can focus on other things.
I agree that process is the primary issue, not materials. And I see four potential issues with the OP’s process: first, is the back lapped and polished flat? If not, no amount of work on the bevel will get you sharp.
Second, there is a significant jump in grit size from the hard Arkansas (about 10 to 11 micron/1500 grit) to the yellow stropping compound (probably around 0.5 to 1 micron but varies significantly by manufacturer). The stropping may simply not be able to remove the scratch pattern left by the hard Arkansas.
Third, I avoid using a strop on straight edge tools like chisels and plane irons, there is simply too much risk of either rounding over the edge or possibly not even getting right up to the edge of a micro bevel.
And lastly, as others have pointed out, using a honing guide can make a huge difference, especially in maintaining a consistent micro bevel when going back to touch up an edge. While honing by hand can work on hollow ground tools if you have a lot of experience, I have been doing this for over 40 years and don’t consistently have that level of muscle memory.