Lifetime Of A Blade and Over Sharpening?

Edge Pal & Pond, I see blades worn down or sharpened like that in meat markets all the time. Perhaps they were of soft steel and they were used a lot, slicing and had to be kept sharp. It is common. Most folks here don't use them as much and hence don't sharpen them as much. There is different treatment of knives outside this forum that is not the norm here. DM
 
David Martin, It is common that people think that they use knifes "a lot". But what is a lot?

I butcher can warn out a knife in some weeks. He works 8 hour a day 5 days per week with a knife in his hand. If we say that this is "a lot" - everything less then that is not "a lot".

I think people use their knifes about 10 seconds per day. Lets say 1 minute per week. That is 52 minutes per year, lets say 1 hour... Then it takes 8 years to come up to what a butcher use his knife during 1 day... :)

I live in Sweden. Here 90 % of the population lives in citys. I think it is similar in US. In all forums the majority of people lives in citys, perhaps 95% - or more. They do not use knifes in the traditional way, they use knifes city- style. They se worn knifes on museums.

Ok, I shall yake some photos of my old knifes and show them here.

Thomas
 
I totally agree. I'd enjoy seeing some of your pictures. Not to belittle those here that think they use their knife a lot. I'm in favor of the increased interest in knives these days. DM
 
Axes and knifes are our oldest tools, thay have been around for a veey long time, first made in stone, then in flint, thennin copper, brons, iron and steel. If you have a Mora knife, that blade design is at least 2000 years old. The Vikings use that knife dor 1000 years ago. It cannot be designed better - for our climate, type of wood, games and fish.

All over the world there is traditional knifes in different design of the blade. Miljons of people jave use it during hundreds, perhaps thousends of years. They dont look as a Scandi knife at all - but they work perfect inntheir climate, their type of wood, games and fish. All those traditional knifes are designed from working with the knife. Not from a person behind a desk.

I dont know how many hundreds knifes I have seen made by young men who have tryed to invent the wheel again - and they have never really used a knife before... I remember one, he have made a very pointy knife with long narrow blade - he told me that it was perfect for skinning games :)

Thomas
 
Hey EP, definitely take some pictures. I've heard your background before, but it still makes me jealous, just a little.

I have a Buck Scoutlite that is over 25 years old. It was my only knife for about 15 of those years. It has been used and sharpened so much that the edge was thick enough to regrind the blade to a flat grind, completely removing the hollow, and didn't narrow the blade width. I ground off some of the kick at the base of the blade too, so the tip didn't stick out of the handle any more. It's ugly, but I still carry it sometimes.
 
Regarding what Edge Pal said about butchers and their knives. I also see that in fillet knives that have been sharpened on a steel, they are almost always over sharpened to the point that the blade is noticeably narrower. I think that most people who use a sharpening steel, have almost no knowledge on how to properly sharpen a knife. I say this, because when I see these over sharpened knives, they usually are covered in scratches where the sharpening steel contacted the upper portions of the blade, not the edge.
 
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The knifes from the top is: my knife for about 5 years during the sixties, a sami knife with a blade from a Norwegian blacksmith. The steel is strange, it become light gray after some time :)

The second knife is the small Taipo Wirkala. Also a good knife for about 4-5 years.

The third is my oldest Victorinox. I in on my third now.

All those knifes are sharpened by free hand with that times sharpener, often aluminumoxide, but also natural stones from the area.

If you use a knife to Everything and the knife is your only tool, knifes looks like this after about 5 years for me. I know people that worn out knifes like this in 2 years. I was careful with my knife. I also carryed a bigger knife for hard wirk in my knife belt, a chopper - in Finland also named Leuuku. So, this knife has not been used chopping or batoned. it is just normal use. It was also my eating knife, I skinned and butchered with it and butcher fish, repair boat ingins, cut Nails and cut of hair when it have grown to long. I use it for whittle, and use the tip for engaving sometimes. the tip has been briken of some times when I use the knife as a screw driver...

The Life I lived for 20 years, far North of the artic circle in the Mountains (alps) was a hard but very nice Life. I do not know what to compare with in US, perhaps Rocky Mountains - or wilderness in Alaska? I live in the midle of sweden today - and that is in the same latitude as Alaska. To the area I lived Before is it around 900 km North from here.

I sharepen by freehand for 40 years. After that I stat to invent sharpening tools - and today I only use tools (not outdoors). I like precision sharpening today. I have become a sharpening nerd - when I like to, or need to. I am soon 69 - and I have sharpen edged tools during 60 years now - and I am still leraning new things every day. It never ends.

Thomas
 
Oh, I almost forgot. A while back I did some work on sharpening and knife lifetime. I basically found that you can dull a knife to the point that you can see the cutting edge apex, then resharpen it and form a very small burr and remove less than 0.0005" from the width of the knife. However, you need a fair amount of experience with the particular knife. Avoiding the burr formation, which I try to do now, would remove even less material.
 
me2, 0,0005" is (if my matematic is correct) 0,0125 mm. Nice!

I can grind down to 1/100 part of 1 degree. First I grind an edge perfectly flat, then I increase the angle 1/100 part of 1 degree and make a new Surface. I can also go between thoes two surfaces and hit them correctly.

When I have the time for it I shall try to go down to 5/1000 part of 1 degree and se If I can do the same thing. My goal is 1/1000 part of 1 degree.

On my homepage you can find a Picture of an edge with two Surfaces with 1/100 part of degree differance. There is also a Picture on an edge there I have made 5 different surfaces. They are about 1 mm wide and straight from the handle out to the tip, it is 0,75 degree between the Surfaces.

I like to be able to make precision grinding like that. Mostly just for the fun of it.

Thomas
 
I remember reading someplace about a study that Remington did in the 1930's about knives. They came to the conclusion that a pocket knife was god for about 2 years or so. Of course, this was a time before WW2 that most people still lived a rural life on the farm. After WW2 and the great migration to the cities, life changed a great deal. But, the fact remains that the knife is essentially a disposable tool that is worn away with use and sharpening. To most people, it's on parr with a 2 dollar screw driver or box store kitchen knife. Only us knife knuts obsess and baby them as cult worship objects.

I've found that the knife I use the most can change the blade profile in a few years. Since I live a pretty urban life, my most used knife is a Victorinox classic. I can take that little knife out anywhere and cut open a package or food wrapper and nobody blinks. In the 4 years I've been carrying this one particular classic, it's cut down boxes, cut twine, plastic blister packages, and list of other materials. It's lost about 25% of the blade. I sharpen on a diamond hone or an old boy scout silica stone. Since they are so low cost and replaceable at any box store, I consider the Vic classic almost as a disposable tool. The scissors get used as light wire cutters, and the blade a general cutting and scraping tool. The SD tip gets used for light prying as well as any phiilips or flat screws I run into. Since it's a daily tool for whatever, I expect to replace it every four or five years.
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The red one is my edc. As I said, it gets used every day for odd jobs. I consider it my 'good knife saver' in that I use it for things I'd never use my 'good' knife for. stripping wire, scraping mud out of the treads of my shoes, lots of opening cardboard boxes sealed with that packing tape that has the fivers running through it that takes the egg right off a knife, breaking down said boxes for the recycle bin. Whatever. You wouldnt believe what I've used that classic for in the the past four years I've carried it, you can see that there's been noticeable blade, compared with the yellow one that my better half carries for the occasional loose thread or mail.

On the other hand, this knife below, was made on the Moran farm bout 1943 or 44 by a German POW that was working there that had worked in the Solingen cutlery trade. He was showing Bill Moran how to make a folding knife, and crown stag and an old file were the materials. Bill used this knife for about 35 to 40 years, but sharpened it carefully. Still, a good amount of blade is gone, as you can see from the difference in the blade vs the tang. Even with very careful sharpening, years and use took it's toll, and the steel was gradually worn away.
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Moral of the story; if you're gonna use a knife a lot and sharpren it a lot, don't buy an expensive knife unless your rich. A knife is after all, a disposable tool made to be used up.
 
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Jack the knife, we have the same opinion :) and your English are better then my English :)

Thomas
 
I've learned from my mistakes.

I had a 270 mm kanetsune yanagi when I first started out doing sushi, it went through the standard 1000 grit king stone as most restaurants would use. After about 3 years it shrunk to half it's depth and became a 240 mm knife.

Now, i polish the knife with a 8000 grit stone. My yoshihiro Yanagi 300 mm is still almost 300 mm after 3 years. It has only been sharpened on a 4000 and 8000. Yes the beginning was a pain in the @, but once sharp it only takes a 30 second polish each morning every morning, very very little steel loss, always sharp.

I never let any of my knives get dull anymore to the point that I have to bring out the repair stones.
 
The question of edged tool life is going to be highly variable based on the type of work said tool is doing. I have a couple of kitchen knives that are 10 yrs or more old and have very little wear. At this rate they could be passed down to my kids when they move out. These have been primarily maintained with a grooved and smooth steel, or a trusty coffee cup.

The utility pattern from the kitchen set I inherited from the previous owners of my house has been used steadily since I moved in - almost daily. It too shows little wear. This set is better quality steel, so gets maintained the same as my pocket/belt knives. Some of my daily use knives are also on a track to be handed down with plenty of good steel on them - part of this is being used in a rotation.

I believe a lot of this is attributable to maintaining at a bright finish on my paper strops or backhoned on waterstones or jointer stones. As mentioned, they never really become dull before being touched up again. If caught early, edge wear might only encompass a depth of a few microns.

Another critical factor is being able to ID and match the existing angle. This allows the edge to be reconditioned with the least amount of additional steel removed, at any finish.

All of the above aside, a sharp edge is a consumable resource - used often and hard, it will not last forever.
 
EdgePal said:
If you use a knife a lot, you also need to sharpen the knife a lot. In that type of life the only tool you have is your knifes and you use it to everything. That is bad for the knifes, they live a hard life. In the same time, your knife must be sharp and I must trust their sharpness with my life. So, they are allways sharp in the same time that they are hard working tools - and that wear down blades.

Thomas
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That was the case with my old Buck 110. Nicely stated Thomas. Now I own many knives that don't see as hard use as that old 110.
 
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Skyhorse, then we have the same experiance :)

it is simple. If I use a knife a lot I must sharpen the knife a lot. Everytime I sharpen I take away material from the blade...simple matematik :)

The strange thing today is that most people never se it on their knifes = they do not use their knifes a lot! they do not sharpen their knifes a lot - and then the blade dont change.

Instead, people like to learn differet methods and chemicals so that they can make a patina on their blades...so that look used and old? They diskuss what to use om blades so that they do not rust? Knives that are in use never rust becouse they are protected by fat, butter, fishoil, blood and other things the knifes are used for. The handles are protected by sweat, blood, animal fat and fat from your hand.

Knifes that are not used needs protextion. I lived outdoors for many month at the time during 20 years. I never oiled my blades during that time. And they never rust.

I think you have the same experiance.

Thomas
 
jackknife said:
Moral of the story; if you're gonna use a knife a lot and sharpren it a lot, don't buy an expensive knife unless your rich. A knife is after all, a disposable tool made to be used up.
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I agree with this completely. On knives that I use, I consider the blades to be like a wheel on bicycle or brake rotors on a car - that is, they're there to be used up.

Reminds me of the Bob Loveless quote.

"A knife is a tool, and if we don't treat our tools with a certain familiar contempt, we lose perspective." - Bob Loveless

IMO, sharpening is a part of that "familiar contempt".


EDITED TO ADD: Thomas, I owe you a huge debt for your kind help in setting up a bent Lansky rod to produce a 3 degree convex. It works wonderfully and I think kindly of you every time I use it to sharpen a knife with it (which is often).
 
EdgePal said:
Skyhorse, then we have the same experiance :)

it is simple. If I use a knife a lot I must sharpen the knife a lot. Everytime I sharpen I take away material from the blade...simple matematik :)

The strange thing today is that most people never se it on their knifes = they do not use their knifes a lot! they do not sharpen their knifes a lot - and then the blade dont change.

Instead, people like to learn differet methods and chemicals so that they can make a patina on their blades...so that look used and old? They diskuss what to use om blades so that they do not rust? Knives that are in use never rust becouse they are protected by fat, butter, fishoil, blood and other things the knifes are used for. The handles are protected by sweat, blood, animal fat and fat from your hand.

Knifes that are not used needs protextion. I lived outdoors for many month at the time during 20 years. I never oiled my blades during that time. And they never rust.

I think you have the same experiance.

Thomas
Click to expand...

I think a simple fact is, not a lot of people really have a lifestyle where they even need a knife in their day to day existence. You've got a lot of knife knuts that buy a knife, baby it and add it to their collection, and five years later it still hasn't got a scratch on the blade from use. But they will boast of it being a "hard use" knife. They show photos of mint condition knives that they've had for quite a while, yet they still look new. So many people obsess over their knives, and probably over sharpen them to get that hair whittling edge.

It's like a Harley guuy I know. He brags about his Harley Davidson motorcycle that he has all chromed out, and rides only in perfect weather down tot he dealership or the local bar, then rides it home and spends two hours polishing it. In the 10 years I've known him, he's put all of 3,000 miles on it. Yet he claims to be a "biker". You have a lot of knife knuts like that. A loty of expensive knives that don;t get used least the get messed up. They want their cult worship item to last forever, so they are very reluctant to use them for the down and dirty jobs that are sometimes needed. But they now how to fake a patina, so it looks used. Never figured that out!

I've always been amazed at how many so called knife people, don't know how to pick up a stone and sharpen their knives. But then, if you don't ever sharpen it, it won't wear out.
 
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