From the Old Fart files

[JDBLADE]

The method of starting off with the blade lying flat on the stone is the way all butchers and meatworkers were instructed to sharpen their blades - it is the only way to remove those shoulders that the factories but on their knives as matter of economics. Prior to mechanisation and factory made knives most knives were convex ground and from all the information I have read on sharpening convex ground blades is to start with the blade flat on the stone or slightly raised. I was a knife maker and I made flat ground blades I made the knives with enough thickness so that they could be sharpened flat on the stone without weakening the edge at all. Scandi blades are sharpened in a similar manner except it is only the bevel that is laid flat due to their sabre grind. If anyone is looking for an authority on sharpening blades using this method go no further than the Razor Edge System devised by John Juranitch (I apologise to John for any mis spelling). Getting back to Knife Makers I am appalled at the number of makers who put all that time and effort into a knife with no consideration to the edge and profile of the blade. Many custom makers will actually use the Lansky system or similar to put the final edge on their blades - when I was making, as I said, I used a system similar to that espoused by John Juranitch in his book on Sharpening.

Unless you are sharpening safe queens, and who does anyway, whats a few scratches on the blade and if you want to avoid this you can sharpen down to about 2000 grit or use a compound on leather to get a satin finish. One of the great advantages of using such a system is that once you have done the original sharpening regular maintenance on a strop will avoid returning to the stones as much as other systems dictate.

 

[Bill DeShivs]

I have not read his book. With all due respect to you and Mr. Juranich, anyone who would put a picture of someone shaving with an axe blade on the cover of his book is more interested in selling books than teaching anyone to sharpen.
The shoulders you refer to are not put there as a matter of economics. It would cost no more to grind a blade to the edge. There is not a knife manufacturer that recommends sharpening a blade flat on the stone, nor do any recommend this sharpening method. I am not a butcher but I can understand a thin edge for processing meat. Many knives are not properly ground to begin with-especially kitchen-type knives. What is being espoused here is that this is the preferred sharpening method for knives in general. It certainly is not. You said you were formerly a knifemaker. Perhaps this is why you aren't still a knifemaker. I am a knifemaker and I have been for many years. Advising people to screw up their knives is irresponsible. Some of these guys pay a lot of money for their knives.
I agree that many custom makers don't have a clue what a knife should do.
Bill

 

[Milu]

One of the criticism's of the Juranitch book is it's bias for knives for the meat processing industry. It is certainly an important book but a long way from being the ultimate authority.

I don't have Bill's experience but I have some experience sharpening freehand and with gadgets and I have to agree with his view.

 

[Gossman Knives]

IMHO, convexing an edge is best done on a belt grinder. To maintain it, is as simple as using an old belt charged with 600 grit aluminum oxide compound. No fancy sharpening gadgets needed. On a full convex primary grind, bringing the edge to near zero (very slight secondary bevel) will give you a strong sharp edge that will last, providing the blade has a good HT. Every knife that I use, the edge is convexed.
Scott

 

[db]

There are many different ways to sharpen. No one method is right for every knife or every knife user. I do the convex on a bench hone because it works for me and I don't really care about resale. It's the easiest way for me to thin the blade grind on factory knives I think they are ground too thick in most cases. I don't really understand the scratched finish part. After I'm done sharpening I've put a really nice finish on the knife that I can reproduce easily after I've scratched it from use.

 

[JDBLADE]

You said you were formerly a knifemaker. Perhaps this is why you aren't still a knifemaker. I am a knifemaker and I have been for many years. Advising people to screw up their knives is irresponsible. Some of these guys pay a lot of money for their knives.
I agree that many custom makers don't have a clue what a knife should do.
Bill

Thanks a lot! As other people know on this forum and other forums I had to give up knifemaking because of a debilitating physical disability. I was a Member of the Australian Knifemakers Guild having met their criteria for acceptance into the Guild. I attended Guild shows and have sold every knife I made and still have people returning for me to make more knives. Further I don't advise people to screw up their knives and I am not irresponsible. I have held classes on knife sharpening for meat workers and hunters and have written numerous articles on knife sharpening. There are many methods for sharpening knives and I use more than one dependant on the knives, the use of the knife, the equipment available etc. For you to reject a time honoured method of knife sharpening out of hand and call proponents irresponsible is not the way people normally debate these matters on these forums.

 

[Cliff Stamp]

What is being espoused here is that this is the preferred sharpening method for knives in general.

No, in fact it was specifically stated that it doesn't work well on a lot of knives, stainless in particular for example simply won't hold that acute a profile and needs a significantly heavier micro-bevel.

Let me ask you a question-do you make knives?

No, the guy that Thom cited in the origional post does though. This is kind of pointless, you don't need to make them, you just need to use them to evaluate how to sharpen them.

I have seen a lot of knives in my life, and never have I seen it recommended by any maker or manufacturer to lay the blade flat when sharpening.

I noted a bunch on them in the above, I'll repeat it again.

Lots of knives are honed with no secondary edge bevels, various scandi ground knives are sharpened in this manner, lots of convex blades are including large choppers, and so are many chisel ground knives, and of course hollow ground knives as the type Thom referenced.

The people that do it don't do so because some authority told them, they do it because it produces the best results they have seen. Again as noted in the above it optomizes the knife fur cutting, edge retention, control and safety.

If you really want an "authority" in Lee's book on sharpening he notes for many knives you can sharpen them by laying them flat against the slack belt region on a belt sander which gives them a very light convex grind.

It produces a bevel of about 8-10 degrees, far more acute than the 15-20 degrees which you recommend, those bevels are in fact heavier than Cook recommends sharpening most axes in "The axe book."

Both of those guys are fairly well respected in regards to sharpening and axe work so if you want to believe something because someone said it there you go.

-Cliff

 

[Bill DeShivs]

"I had to give up knifemaking because of a debilitating physical disability."
I'm very sorry. There is no intentional disrespect on my part.
You guys sharpen your knives however you want.
There is a way to sharpen knives without ruining the blade finish, though.
Bill DeShivs

 

[JDBLADE]

Have you every seen a "competition axe" there are no scratches on them. You can sharpen a blade without leaving scratches it is just a matter of what you want at the finish. No butcher is going to worry about a scratched blade. All my "good" flat ground blades are finished with a satin finish.


The use of “flat grinding” a blade is not only used to produce a “zero” edge – it can be used to remove the current “shoulders” from a blade and then put on a secondary edge of 15 degrees for example or you can go further and use a “triple” grind. As with all sharpening it depends on the knife, its intended use, the profile of the blade, the steel used – its known edge retention and toughness qualities, and of course the known heat-treatment. No responsible person is going to sharpen a knife beyond its known capabilities. But, there are many knives that are able to use the “flat grinding” method (flat grinding does not necessarily mean laying the blade flat EG it may be raised the width of a matchstick in some cases again dependant on the properties of the knife) to produce an edge which is sharper, is tough and has good retention than following the factory edge. The use of “flat grinding” is nothing new it has been around as long as there have been blades and has been used by various societies around the world. It has been tested over and over and would still not be used today if it had been found wanting. It is not only in knives that this system has been used there are many tools EG chisels, planes, axes and scissors to produce sharp, tough edges. As in all things it is a matter of “horses for courses” and the same goes that there is not one single sharpening method for all blades.

 

[Bill DeShivs]

I understand what you are saying. Apparently you don't understand what I am saying. It really doesn't matter. I don't care what butchers do with their knives. We aren't all butchers, and I just don't want someone who doesn't know to butcher a good blade.
For ten years I have been disseminating information about knives on the Internet. Sometimes I wonder why I bother.
Bill DeShivs

 

[Cliff Stamp]

There is a way to sharpen knives without ruining the blade finish, though.

Yeah, and if you use them it gets scratched up anyway, plus cosmetics are not a real issue on working tools anyway, it is how they perform that is of importance.

Have you every seen a "competition axe" there are no scratches on them.

Yes you can just raise the finish right back up to mirror if you want, generally though this usually isn't of significant benefit.

No responsible person is going to sharpen a knife beyond its known capabilities.

I do at times, it is a matter of what you want, you are always considering cutting ability vs durability and it can be of benefit to go beyond optimal both ways at times. For example I leave my tramontina bolo so fine it typically will have several dents/rolls at the end of a day of limbing. I could increase the angle to prevent this but then the cutting ability would be lowered and this would increase glancing, raise fatigue and lower productively in general.

But, there are many knives that are able to use the “flat grinding” method (flat grinding does not necessarily mean laying the blade flat EG it may be raised the width of a matchstick in some cases again dependant on the properties of the knife) to produce an edge which is sharper, is tough and has good retention than following the factory edge.

Yes, I have a few blades that I hone right flat to the stone, no raise, but depending on what I am cutting I will raise them a little after the edge has been created to microbevel slightly higher if I have to cut tougher materials. It depends on the steel and heat treatment, ref :

http://www.bladeforums.com/forums/showthread.php?p=3369270

Of course the tricky part is the known bit, it takes a bit of experimenting to find the optimal angle and it differs from person to person depending on skill and strength and methods of use. I usually run that O1 blade full the the edge, no lift as it is mainly a kitchen knife, when I do utility work, cardboard and ropes I leave it the same, when I move up to thick plastics and hardwoods I increase the angle to 4+ degrees per side.

I will be working with a M2 blade at 65 HRC next which should be interesting. I expect it to be able to go finer than the O1 blade significantly, it has a full convex grind though so has a much more robust cross section. Relatively of course, it is still 1/16" stock.

http://www.physics.mun.ca/~sstamp/images/aj_skinner.jpg

The shiny part is the actual edge bevel, it was hone flat to the stone, then lifted to create a tiny microbevel. I'll grind this off initially, see what it takes to damage it in use then work up to see where it is stable.

-Cliff

 

[JDBLADE]

Quote:
No responsible person is going to sharpen a knife beyond its known capabilities.


I do at times, it is a matter of what you want, you are always considering cutting ability vs durability and it can be of benefit to go beyond optimal both ways at times. For example I leave my tramontina bolo so fine it typically will have several dents/rolls at the end of a day of limbing. I could increase the angle to prevent this but then the cutting ability would be lowered and this would increase glancing, raise fatigue and lower productively in general.

I meant that in the context of offering advice in that I was called irresponsible for proffering a certain sharpening method. I too sharpen beyond a knives known capabilities in an endevour to find the optimum edge for different knives.

 

[Cliff Stamp]

I meant that in the context of offering advice in that I was called irresponsible for proffering a certain sharpening method.

Yeah, that's off, what would be irresponsible would be for example noting the use of belt sanders without commenting on the possiblity of overheating, or talk about buffers without noting the possible consequences of blade catching. In Thom's post right away he notes that this will effect the blade finish.

I have been guilty of this on occasion when I reference sharpening with small stones on convex edges. I usually hold the blade fixed and hone the edge with the stones, often running from edge to spine which can lay your hand open if you are not really careful.

Here are a few shots of knives sharpened very low in the manner Thom described :

http://www.panix.com/~alvinj/ggrampa3.jpg

http://www.panix.com/~alvinj/jack.jpg

These are newish rebuilds, after extended use they start to look like this :

http://www.panix.com/~alvinj/P347-1.jpg

http://www.panix.com/~alvinj/HSSknife.jpg

Cosmetics are effected, but it is a knife, not a painting. Do you complain about the way your hammer looks or how it drives/draws nails?

Of course if you really can't stand to have the blade scratched up, just tape the body and leave the edge bare.

As soon as you use it, the body will take a patina and scratches of course, even cutting cardboard does this readily.

-Cliff

 

[thombrogan]

Bill DeShivs,

Please read the first post in this thread and take note that many of your objections (except your ad hominem attacks on JDBlade and capitalism via Juranitch's cover photos) were mentioned. Not wishing to attack JDee or free enterprise, I omitted those.

Yes, this will scratch the blade.

Yes, there are other methods - including ones I prefer and otherwise recommend.

No, it shouldn't be done on a collector's blade. Unless you are or will be famous and people want to buy the knife you used. In that case, going all Kentucky Mint on the blade is counter-productive.

Yes, it's a very old method and is used by people that use knives to cut things and would rather increase the cutting ability of their knives at the risk of messing up the finish.

It's all there. Except for those other two things.

 

[Bill DeShivs]

Thom
I reread the post, and must have missed that part. Sorry for the confusion. I'm a restorer of old collectible cutlery, and it certainly colors my views.
Bill

 

[metallicat]

Thought you said somewhere that you are a knife maker? Post some pics of your knives. What are they? folders? fixed blades?

 

[Bill DeShivs]

Who, me?
Do a search for "Leverletto."
Very few customs lately- mostly designing autos, and doing restorations.
Bill

 

[metallicat]

Interesting design that leverletto...is it only manufactured by AKC? (sorry don't mean to hijack the thread)

 

[Bill DeShivs]

AKC has the rights to the Leverletto, except for customs done by myself.
Bill

 

[bladefrienzy]

Check out some BarkRiver Knives , all of them come convexed and you sharpen them easily with the mouse pad stropping method. I have one of their woodland model knives and have put it through more hell than any of my tactical folders and it always holds up as well as stays sharper longer than any , yes any of my "normally" sharpened knives. IMHO Steve