Add a Comment

Comment by Thomas Lofvenmark on July 15, 2013 at 6:12

Today old knowlege of sharpening is almost forgotten. Today people dicuss how they can get edges as sharp as possible, razor sharp and above. That means that they really discuss how to get as low retenetion on the edge as possble, or, they work hard to get an edge as useless as possble for outddor jobs. Why?

I have lived most of my life outdoors and I jave use knives, and sharpen them for more then 55 years now. For me it is necesarry to be able to trust my life on that my edges allways work and that they are functional. My edges are 95% sharp and they have a good retention so that I can use them as long time as possible before they fo dull. For me, that is a purpouse of a good edge.

I live in scandinavia and our edges is normally 20-25 degrees total edge. We use low angles and our knifes are known as small - and very sharp. The design of the normal belt knife blade have not change the last 1000 years. The Vikings use the same blade we use today. For our climate and our type of wood, animals and so on, this is a very good blade design and sharpness/retention.

Traditional, we do not chop with our edges. If we need to chop, we use axes or special bigger knifes, so called "choppers". Normally (in younger days) I carry two knifes, a chopper and a ordinary belt knife. I use a special knife belt for the knifes. In that belt I also cary needles and thread so that I fast can repair my cloth. When it is very cold, this is necessarry.

I have talk about the most important things, sharpness and retention. There is also a thing like "penetration skill" who is important for an edge, that is mostly about the blade profile, but also the edge degrees. A very thin edge penetrate good - but you cannot use high pressure, if you do, the edge will broke. If the edge angle is to big, it will not be able to penetrate at all, even if it is very sharp, the edge angle is to high.

That it is why it is very important to know to what the knife shall be used. What shall the edge be able to penetrate? An ishokey puck - or balsa wood...shall you work in oak wood - or birch wood, along the wood fibers - or across the wood fibers. If you only use your knife along the wood fibers you can use very low degrees on your edge. If you mostly use your edge across the wood fibers, you need some more degrees ( more steel) in the edge.

As I wrote above, here we use low edge angles. To make the edge stronger we use a secondary bevel (honing edge). That do not change the edge penetration skill in most materials, but the edge will increase its retention a lot. I can use the knife longer times before I need to sharpen the edge.

The hooning edge we use is veey thin. When you can se it with your naked eye, it is finished. It is about 2 degrees higher then the ordinary edge. When this 2 degrees edge is made, I use the knife and evaluate how it works. If I need a little more retention, I regerind this edge to 3 degrees, or 2,5 degrees. If I like the edge to be a little sharper, I regrind the edge ro 1.5 or 1 degree. This is to "balance" the edge so it fits just my demands and just my way of using just this knife for just this purpouse.

In my mind, the most important in all this I have wrote is about the old common knowledge - an edge can be to dull - and to sharp. Both are very bad things on an edge. An edge shall only be as sharp it need to be for its purpouse. Not sharper then that.

That means that a razor knife shall be razor sharp. The purpouse for a razor knife is to shave face hair and it need to be very sharp, and thin, to be able to do just that.

All other knifes have less sharpness and higher retention so that they can be used for a long time before the edge gets to dull for its purpouse...

If people understand this, most people can sharpen an knife edge properly - but perhaps not sharpen a razor knife properly.

Thomas

Comment by Thomas Lofvenmark on July 15, 2013 at 6:11

Robert, Lansky, Gatco and DMT is three US sharpening tools who works in the same way, they use the law of physics. Lansky have 4 fixed angles, Gatco have 6 fixed angles and DMT have 8 fixed angles. They are all nice tools to work with and the edge will be flat ( it cannot be anything else).

"Two flat and smooth surfaces who meet each other in a low angle = sharp". This sentence tells you 4 things: flat, smooth, meet each other, and low angle.

Those tools will give you flat edges.
The sharpener you use last on the edge decides how smooth the edge will be.
Meet each other - you must check out your self.
How low the angle shall be to be functional in the balance of sharpness and retention decides on to what you shall use the knife.

A very low angle are sharp with no retention = the edge will go dull very fast. It is too less material in the edge. Add more material to the edge and the retention increase = go up in degrees.

There can be two very bad things with an edge, it can be to dull - and to sharp.

In old times, men, woman and children could sharpen knifes. It was a common knowledge and It was a question of survival. They understood that an edge shall only be as sharp the edge needs to be for its purpouse, not sharper then that. (Razor sharp edges is a Hollywood product).

You know, shaving knifes exists, they are named razors. IF people shaved them selfs with their belt knifes, the razor knife will never have been created becouse there was no need for it. But, the razor knife exists, that proves that no one shaved them selfs with their ordinary knife.

If your belt knifes is so sharp that you can shave your self with it - it will get dull the first minute you use it for things a belt knife shall be able to do. Then you have a useless dull knife...

Thomas

Comment by Alexander Noot on July 12, 2013 at 2:11

I agree, I tried freehand (and I still do freehand every now and then. But for setting a bevel there really is no better budget system than the DMT aligner set with an added extra fine stone to it (the brown one) finished off by a loaded strop.

In Memoriam Comment by Robert Burris on July 11, 2013 at 12:33

Thanks Jack, for the info on the DMT. I might have to get one.

Comment by Jack Haskins, Jr. on July 11, 2013 at 11:00

DMT:  Diamond Machining Technology

http://www.dmtsharp.com/sharpeners/bench-stones/

Great products.  I have several of their tools including bench stones.  Diamond stones are great but before you use any there are a couple of things to know or you will ruin the stones and/or not get the performance they are capable of.  Not to be concerned.  Just characteristics of the tools that is diamond sharpeners from all companies.  I have been VERY happy with them and after going through a few other types of knife sharpeners I've settled with DMT as one of the types I'll stick with.  The only company I want to try is Atoma but the prices are more than I want to pay.  I believe the performance is higher including life span but for someone who only sharpens his/her own knives DMT is GREAT.  If you sharpen professionally, all day long the Atomas are probably the way to go.  Or, just if you can afford it.  If I had more money I'd get them.  When it comes to tools I always want the best I can afford.  I just can't afford the best all the time.  Hope this helps.

Jack

In Memoriam Comment by Robert Burris on July 11, 2013 at 10:27

Alex and Jack, I'm not familiar with the DMT. What's the company name besides "DMT" ?

Comment by Alexander Noot on July 10, 2013 at 8:47

I love my DMT aligner. It's the best balance between effective, affordable and portable. My favourite jack of all trades system.

Comment by Jack Haskins, Jr. on July 10, 2013 at 6:49

The DMT aligner is a clamp system similar to the Lansky I think.  I've never used a Lansky but I had the aligner for about a year.  It's good but there are a couple of things about clamp systems that are imperfect.  Then again nothing is perfect.  When a bag of money came my way I got the edge Pro which I'd had on a wish list for a while.  You need a bag of money but it's worth it as long as that bag of money isn't needed for groceries. :)   But if you only want to spend $60 the aligner with the diamond stones is VERY good.  I have ezlap diamond files and they are good.  The DMT products are very good also. I have several of their sharpeners also including bench stones.

Comment by Lee Smith on July 9, 2013 at 22:13

I've been using eze lap diamond stones freehand but as I get older I cant seem to hold the knife as steady as I used to. I noticed they are offering a system similar to the lansky but with diamond stones. Has anyone tried them?

In Memoriam Comment by Robert Burris on July 9, 2013 at 22:07

Thanks, Thomas, I guess I have not mastered the Lansky. I am sure they are a lot more accurate than my old cripple arms. I am sure, your info is being read by other members, they are just remaining silent. The more that our members are able to sharpen their knives, the more they will enjoy them.

   I hope we can keep this group active. The old timers and experts at sharpening should remember, "there is a lot of members, still learning the art of sharpening". The more helpful we can be, will just help everyone.

    Thanks for all of your information. I would love to hear more.

• ‹ Previous
• 1
• …
• 12
• 13
• 14
• 15
• 16
• …
• 22
• Next ›
• Page