I was teaching my apprentice how to sharpen a chisel and I realized that he didn’t’ know how to tell if and when it was sharp enough.
I just put my finger to it and slide it somewhat diagonally and I know, teaching it is not as easy as it may appear.
Long time ago I was the apprentice of a European master, he was able to blow a hair against the edge of a chisel and cut it. I don’t know if he had exceptionally powerful lungs, but I tried and tried (and I still do sometime) to no avail.
How do you test an edge for sharpness beside shaving ?
C.
Replies
Hi C , When I apprenticed it was sharp when it did not pull the hairs , but sliced them off my bald wrist .
regards dusty
It's been many years since I have bothered with testing edges. No matter what the test, the point is being able to quickly attain an edge which does the work as intended.
You no doubt know before you test when it is sharp enough. Shaving hair is one of the worse tests to perform. An edge which can shave hair may not be able to pare Pine well. Which was the test I was taught, paring end-grain Pine easily with no crumbling. In one sense it is a "real-world" test.
When I have taught handtool classes, as long as the attendees worked their way up through the grits ridding themselves of the previous grit's scratch pattern, and did not create a dubbed edge it pared wood with ease. That's sharp enough. That I had them confirm--I like that word and concept better than test--using end-grain Pine, was for their own confidence building. Before they did this confirmation step, they are taught to simply look for telltale signs of edge rounding. Then they were told the consequences of the presence of rounding or the lack thereof. When they do finally pare the Pine, they knew what to expect.
After that, those who did have a slight rounding worked on technique to prevent dubbing the edge. Not dubbed, honed to 8k and no visable scratches equals sharp.
Back when I taught my sons, it was always in conjunction with working wood. So if it did the work, it was sharp enough. They are the closest I have had to apprentices. They all sharpen well to this day. Good enough I would let them attack a commission with me. That's good enough.
Take care, Mike
Mike,Your reply helped me realize what I really meant to ask, thanks.
When I pick up a chisel, I automatically check it for sharpness, I run my finger on the edge and I know if it's sharp enough for the task at hand.
There isn't really a way to teach that, is there ? One has to keep at it and it will come, I guess.C.
Hi C,
Yeah, I think we can teach the proper mechanics of sharpening. Some will get it faster than others. That is to be expected. But after that it is a mixture of practice and use which ultimately is the best teacher.
For one of my sons, sharpening was more difficult than for his brothers. It wasn't that he didn't understand the mechanics, it was performing the mechanics that was troublesome. That was when I bought the shop its first honing guide. It elevated his sharpening immediately. More importantly for the shop, it made him instantly more productive.
Over a little time, the muscle memory kicked in. Then it was him getting tired of the extra time to hone, and the honing guide was dropped from use [except for repairing or changing bevel angles--we all do that].
Anyway, time and experience is the best teacher.
Take care, Mike
You are right Mike, for some people is much harder but I noticed this: people that have a hard time sharpening have a hard time tying knots as well ! There must be something in common there.C.
Now that is funny--and could be true!
I think part of the larger issue is one of age or era. At least for me. I'm just old enough and my personal history involves growing up sharpening all sorts of edges. From saws to axes, froes and adzes, my grandfather and great uncle were great, if not hard, teachers. Included their use as well. And there was a lot of use.
Too, even in Cub Scouts [and later in Boy Scouts], further education in sharpening and tool use was taught. Then there were the wonderful Jr. and Senior High school shop classes.
In the 1970s, it all came together for us when we packed it all up and moved to the mountains in N. Idaho and built a log cabin. My boys were all taught to sharpen their knives for various tasks, axes and hatchets were used daily and needed honing frequently. The adze I used for the joists and some of what became the timbers for the cabin was in the family for a hundred years. Heck, I still have [and use] the hones we used and they were bought by family in the early 20th century.
Well, enough commiserations. My youngest has challenged me to Father's Day rounds of chess. So I bid you Happy Father's Day. If you are not a father--pass it along to yours!
Take care, Mike
That's too bad; I must be younger than you, because I was in Cub Scouts and Boy Scouts as well (even made it to Eagle), and also took shop in 7th grade, but I was never taught to properly sharpen a blade. Heck, the only thing I was taught in shop class was how to sand with a block and sandpaper; spent the entire year doing that! Oh yeah, we also learned how to sweep the floor. It took a long time for me to regain any interest in woodworking after that class. :-(As for shaving, I've read about this before. Basically, the type of blade that's good for shaving hair isn't the same kind of blade that's good for chiseling or planing wood. Micro-serrated blades actually are very good for hair, whereas that's totally undesirable for a chisel. It's hard to tell this with our crappy human eyes, but if we could look at all these blade edges under a microscope, it'd probably make a lot more sense. I wonder if anyone has a website with this kind of information, with photomicrographs to illustrate.
Edited 6/18/2006 3:52 pm ET by dwolsten
Could have been the local troops, too. Heck, we even helped build cap and ball rifles and took them to the ranges to learn to handle rifles properly. The rifles were raffled off for a fundraiser. We did lots of that sort of thing.
7th grade woodshop I spent the first semester using a lathe--my dad even still has the ugliest ashtray stand on the planet! But part of that semester--the first portion--was learning about the lathe, safety and sharpening the tools.
Second semester was bandsaws. It was during 8th grade woodshop we started to learn handtools. Seems backwards.
But by public school woodshop classes, I had hewn many timbers as a lad. Chopped lots of notches. Heck, my grandfather, brother and I even rebuilt a small log cabin somewhere up in the Washington Cascade mountain range. I was probably 7 or 8 years old then. We spilt out replacement shingles from some old Cedar and the whole bit.
Take care--back to chess. He's whipping me today!
Mike
True, it may have been differences between local troops. I was in one troop for a while that wasn't very good; the Scoutmaster was only there so he could get his son through Eagle, and as soon as that was accomplished, he quit. He didn't expend any effort in helping the other kids advance. I left that troop and went to another one which had an excellent reputation locally.Even so, I still think there's a big generational difference. I'm 32, and I think we didn't do nearly as much hands-on stuff as older people did as children, and I think the current batch of kids is even worse. No one wants to do anything these days because there's a remote chance that someone stupid might get hurt, and then people and institutions will be sued by evil, greedy lawyers and they won't have the funds to continue operations.I wonder if they even have rifle shooting in Boy Scouts any more? We didn't build our rifles like you guys, but we did get to fire 50-cal black powder rifles. That was loads of fun. Especially when the Scoutmaster (this was in the new troop, not the one with the crappy scoutmaster) tried to get me to shoot at another kid's target since I was shooting multiple bullseyes and he couldn't hit his.I think my worst nightmare will have come to pass when I check out Boy Scouts again (perhaps for a son of my own), and find out that rifle and shotgun shooting and most of the other hands-on outdoorsy merit badges are phased out, and the most emphasized ones all involve business, law, politics, diversity awareness, and human resources.
Speaking of children, I finally won a game of chess today!
Yep, I'm fifty. Lots of time between the two of us as regards legal liabilities. That is perhaps one of the factors which changed the scouts. The litigious nature of parents has changed many things over the years.
My boys didn't have the chance to be in scouts as we lived in the cabin during their early years. They did learn to hunt and trap, make fish lines, identify and gather wild edibles of all sorts. Teachings I owe to the scouts and my family were taught to them. And there were the cabin raisings and social events, especially during the dead of winter. One of my favorite pictures of being up at the cabin is when on a 4th of July we got out the cap and ball rifle and I taught my oldest, then 4, now 31, to load and fire it.
I think that even sans scouts, you can do a lot of these things with your children when the time comes. We're doing some of these with our granddaughter. Fishing is a way of life for her. Hiking? Every chance we get. Plenty of opportunity to crack open the books and identify plants in situ. Even cook some up or eat them raw, once we identify them. No matter where we live, there's always a bit of nature around us to explore, share and learn from.
And shop experiences. My granddaughter is still finding her way. She started out wanting to scrollsaw. That lasted a couple months. Then she has tried whittling and carving. No matter what she tries, she comes back to whittling. So we are going to get her a knife or two of her own. Along with the knife will be a ceramic stone to sharpen with, which her father will teach her to do. So it goes. Generation to generation.
Take care, time to go see if I can win a second game today before we do the BBQ!
Mike
dwolsten,
Rifleshooting (.22 cal)- b-b guns for cubs- and shotgun merit badges are still part of the BSA "curriculum". Shooting muzzleloaders is, I believe allowed, as part of a re-enactment experience, as long as the loading is done with one-on-one supervision. Pistol shooting is prohibited, except for I believe venture crews affiliated with a police dept. Two merit badges most recently dropped include blacksmithing and bee-keeping. I'm not an active scouter any more, but was up til about 8 months ago. You are correct that the activities, camping, etc are what make a troop successful in retaining boys. We used to regularly give the older boys opportunities to make their own camp stools, knives, snowshoes, etc. New scouts made their own "sporks" (spoon on one end of a wooden handle, fork on the other) that they eat with on campouts.
Bragging now, our troop boasted one of the area's highest rates of Eagle attainment, with several pairs of brothers both making Eagle, my two sons included. Parental involvement, and lots of varied activities, are key to a successful troop. Trained leaders of course, are essential- the BSA's training program gives a S'master all the tools to make a troop go.
Off my soap box now,
Ray Pine
dwolsten , As Ray has said Rifle and Shotgun are still Merit badges but we are no longer permitted to teach about foraging roots and other wild goods , I guess too much liabilities as has been stated .
Most other merit badges still exist and a new Hunting Merit badge is close to being offered , still in the experimental stage last time I checked the only thing a Scout can kill is a Trout or the likes .
You can go to http://www.meritbadge.com to look up the current offerings .
dusty
My experience with Scouting is that the boys primarily learn what the leader is interested in. I was fortunate enough to go through the program in rural Montana during the 50's/60's with a great Scoutmaster who appreciated the traditional skills and outdoor life. One of the badges we earned was not a "listed" merit badge, but rather was unique to our council. It was call "100 Degrees of Frost". You got 1 point per degree below freezing for camping out for the night. After 100 points you earned the badge. I got my quota in only four nights. The purpose was to teach cold weather survival, and it certainly did that.
As far as my sharpening skills go, I learned those from my father. We lived on a farm and ranch, and the items needing sharpening seemed to have no end. In an environment like that we become privy to many skills that our brethren that were raised in the cities missed. Many I no longer have a use for (horse shoeing, e.g.), but there is no such thing as useless knowledge.
Ken
> people that have a hard time sharpening have a hard time tying knots as well <
I think there's a 'native' skill factor - some people have it, some don't. Same with languages - some people pick up a second/new language quickly, some have to work hard and never get the sounds right.
You're born with those attributes - hence 'native' skills.
Malcolmhttp://www.macpherson.co.nz
Absolutely right there Malcom, but what I really wanted to point out (and try to verify) was the fact that people that have a hard time learning to sharpen have a hard time tying knots as well.
There must be a common skill or aptitude requirement there.C.
Over a little time, the muscle memory kicked inLONG ago I use to set-up Brown&Sharp screw machines.. I sharpened more drills than I care to remember!The statement ... the muscle memory kicked in is about as TRUE as it gets.. Also my boss sayin' I'll be fired soon if I don't get it right.. AND if I get it right I get a 10 cent raise!
C, I have asked that question before on this forum and never got an answer that came near what I have been doing since I was first taught how to sharpen a pen knife and check its sharpness-at about age ten I think.
Assuming one has not modified the finger tips these are extremely sensitive-by design-ask a doctor, and I believe the best way to check sharpness. One draws a finger tip along the edge-gently. A smooth sharp edge as on a mirror polished razor or scalpel will produce a drag as it cuts microscopically-this drag is what one gauges. And no my finger tips are not all cut up or messy-the action is done gently. In this way one can feel variations in the sharpness of the edge from one end to the other.Similarly one can feel if the edge is serrated as when a rough stone has been used-the edge is sharp but good for meat cutting rather than wood paring-but both will shave....shaving is only a general indicator.
I can hear the howls of derision already, but I assure you I have had this method confirmed by numerous old pros (from the original British apprenticeship system) and made quite a few "lads" see that they have been deluding themselves by using methods like nail paring , or testing on wood etc
philip, every worker has the potential to reach a point where there is no need to test how sharp an edge is. With experience you just know it's sharp enough. I call it the sharp'n'go method. It's funny but I've mentioned the sharp'n'go philosophy twice today in two forums.
Anyway, if I'm demonstrating sharpening, I do shave a few hairs off the back of the hand, but I already know it's sharp before I do that, ha, ha. Slainte.Richard Jones Furniture
I know that-but I merely answered he question which was how does one test for sharpness, other than using the thing.
Your philosophy is for those "doing the job"-no slight intended. For those really interested in differences say from one type of stone to the next etc: well its another ball game.
I still just like to feel the thing -habit of years.Philip Marcou
Hi Philip
Some years ago I watched Norm in the NYW demonstrate sharpening blades using a Tormek. It looked so easy and the edge on the chisel he honed effortlessly sliced news print. I said to myself, I gotta get one of those! Some months later I was able to try one out at a woodshow. The demonstrator honed up a plane blade on the stone wheel, stropped it on the leather, pared the hair off the back of his hand, and then handed it to me. I ran my finger over the edge - and knew that this blade would be just awful in a smoothing plane. I could feel the slight serrations with a finger tip. The strop had simply turned them into shiny, sharp serrations,. The edge was not smooth but really a miniture saw with tiny, tiny teeth.
About the same time I brought home a brand new Mujingfang smoother. In my impatience and excitement I ran the plane and blade as is over a board to try it out. It cut the whispiest of shavings, and I was immensely impressed. Then I felt the surface of the board, and it was rough. Holding the edge of the blade against the light revealed the scratches I knew would be there.
I have always equated sharp with a smooth edge, the smoother the "sharper", and this is fairly easy to gauge when one knows what to look for and what not to be fooled by.
Regards from Perth
Derek
I wouldn't go from Tormek to wood. I use the Tormek to put a bevel on, and to grind away dings. Sharpening and honing is left to the waterstones.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
Derek, stropping has added sharpness to the saw tips by polishing hem. The serrated blade will not stay cutting well for as long as the mirror polished blade, because less of it is sharpand the saw tips break down quickly especially on hard timmber.
Each to his own- I just gave the method I use to test for sharpness, which can also equate to gauging the actual condition of that edge-if it be "rough" or "smooth". I am not dictating which is better for woodworking because timbers have such a wide range of characteristics-in some cases I might prefer a "saw" edge because it may cut better than a polished edge.
At the end of the day there is no magic in it for me- no scarey juju etc-all I want is for the blade to get sharp chop chop with minimal fuss-and that means the use of only one stone /plate and sometimes a second finer one. I may strop chisels in between sharpenings to extend working time.Philip Marcou
Philip,
I was taught that method by Ted Baly in 1972. He in turn had been taught by a well known country maker in Devon who used to write for Woodworker magazine. I regret that I cannot remember his name.
I love it, but find it unwise to mention to my less dextrous beginners.............
My current preferred method is to look, i.e. to rotate the edge under a directional light.
Bluntness or damaged areas reflect light. This reflection or brightness is Jim Kingshott's candle (Spelling?). An absence of "nuffink".
Leonard Lee's book, "Sharpening", has excellent electron microscope pictures of edges. Better polish and flatter surfaces produce the sharpest edges.
In my experience stropping on soft surfaces like leather damage and round the flat side or back. Fine for carvers but not so good for bench chisels.
Harrelson Stanley has an extremely counter intuitive technique, in his recent Popular Woodworking article, which I will be trying soon.....
Any edge which gets the job done is fine with me. Some jobs do not require perfect sharpness. I also agree with Sgian, that most planes can be made to work surprisingly well, if you follow basic principles.
David Charlesworth
David, I would be interested in H Stanley's approach-let us know when you have had a look.
Stropping chisels? I found that it was useful when I had Makore to work with- if there is any timber more abrasive than that I would prefer to keep away from it.
These days I am looking at things and seeing something else so again prefer to feel rather than look. I would have liked to show Jim K two razor blades, say one Gillette and another el cheapo-would the candle/looking method show a difference, other than showing that both are sharp? As a matter of interest I have found that the el cheapos are often not uniformly sharp across the full width.
Taking things to extremes, I know, but it does show how usefully sensitive the finger tips are.Moral of the story: keep away from cheap razors(;)
Philip Marcou
Hi Philip
We are likely on the same page. My reference to a Tormek (which I do not own) was only to illustrate the point about a serrated verses a smooth edge, which you raised. Just to clarify, I work up to a 8000 waterstone and aim for a smooth edge, and check both by feeling (for smoothness) and by looking (for, as David noted, the absence of reflected light).
Regards from Perth
Derek
Edited 6/20/2006 1:45 am ET by derekcohen
Derek- confirm you are feeling by running finger(s) along the edge rather than across?
Another point in favour of actually feeling the edge is that one may think the burr has been removed, but in fact it is level with the back and hard to feel by the usual method-but it will feel "rough" when you run a finger along it...
I have harped on enough -just now folks are gonna start wondering.Philip Marcou
I say it is sharp if it will shave the end grain of a plain old pine stick..
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