The Razor Edge Book of Sharpening

Thank you. I've seen a bunch of references to this and been wanting to read it, but none of my local libraries have a copy.
 
I've had a copy forever. Nice to have in your sharpening library.
 
Very Good. :thumbsup:

Downloaded the .pdf and even saved a copy to my phone, to peruse when I otherwise have nothing to do besides stand in line or whatever. Should be good reading. :)
 
Thanks, 000Robert. It looks pretty basic and dated, from what I can tell. Maybe I shouldn't judge a book by its cover.

Previous reviewers have said he recommends a blade width of 0.2 inches at one-quarter inch back form the apex. That geometry works out to a 4.6 dps edge, which is extremely acute. A microbevel would knock raise that angle, but it's still pretty acute.

I've recently switched my Rukus edge from 15 dps to 20 dps, so it could handle some chopping. The edge holds up a lot better know, with not much loss of slicing ability.

If I remember correctly, Larrin found that edge angle is a greater factor in slicing ability than edge width. When I came to the forum many years ago, the gray beards were saying that edge width (behind the edge width) is more important than edge angle, given equal edge sharpness. I've found that a edge width 0.015 inch is pretty ideal for me, but 15 dps and lower starts to see accelerated damage from chipping and/or rolling. An edge width of fifteenth thousands and a 20 dps works really well for hard-use knives. Light-use knives could go lower.

I did order the book from Amazon, but my sense is that any sharpening book in today's world has to include high-wear powder steels and diamond sharpening systems. And guided systems are going to be a lot better for anyone wanting the ability to sharpen knives quickly and easily, without investing years in building up muscle and brain memory.
 
Twindog said:
Thanks, 000Robert. It looks pretty basic and dated, from what I can tell. Maybe I shouldn't judge a book by its cover.

Previous reviewers have said he recommends a blade width of 0.2 inches at one-quarter inch back form the apex. That geometry works out to a 4.6 dps edge, which is extremely acute. A microbevel would knock raise that angle, but it's still pretty acute.

I've recently switched my Rukus edge from 15 dps to 20 dps, so it could handle some chopping. The edge holds up a lot better know, with not much loss of slicing ability.

If I remember correctly, Larrin found that edge angle is a greater factor in slicing ability than edge width. When I came to the forum many years ago, the gray beards were saying that edge width (behind the edge width) is more important than edge angle, given equal edge sharpness. I've found that a edge width 0.015 inch is pretty ideal for me, but 15 dps and lower starts to see accelerated damage from chipping and/or rolling. An edge width of fifteenth thousands and a 20 dps works really well for hard-use knives. Light-use knives could go lower.

I did order the book from Amazon, but my sense is that any sharpening book in today's world has to include high-wear powder steels and diamond sharpening systems. And guided systems are going to be a lot better for anyone wanting the ability to sharpen knives quickly and easily, without investing years in building up muscle and brain memory.
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Copyright is 1985. I love my Wicked Edge 130 but it's good for everyone to be able to hand sharpen just in case.
 
Twindog said:
Is there a central insight or philosophy to his sharpening system?
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It helped me realize many years ago that I had to make sure that my ground tapers went all the way to the micro edge (look for burrs). Great book. Thank you John.
 
"years building muscle and brain memory"
Learning sharpening by hand takes a couple of days!
 
The book made me realize how important that the edge relief is. I didn't pay much attention to the relief before I read the book.
 
Bill DeShivs said:
"years building muscle and brain memory"
Learning sharpening by hand takes a couple of days!
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If they had you to teach them, it could be done in a couple hours. But unless they sharpen a lot and until they get their muscle/brain memory down, they'll still run into problems down the road. If you spent that same amount of time teaching them to use a Wicked Edge system, they'd produce much better edges pretty much forever.

And talent will always play a role.

I had a friend who could pick up almost any musical instrument and be reasonably proficient in an hour or so. I have a tin ear, limited musical memory and only coarse pitch recognition. I can't even tune an instrument, unless I have an electronic instrument tuner. Then I hit it right on. We're all different. We all have different abilities.
 
000Robert said:
The book made me realize how important that the edge relief is. I didn't pay much attention to the relief before I read the book.
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By "edge relief" do you mean the two edge bevels that meet to form an apex? Why would that not be obvious? I guess I'm going to have to read the book.
 
Twindog said:
By "edge relief" do you mean the two edge bevels that meet to form an apex? Why would that not be obvious? I guess I'm going to have to read the book.
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The top of the edge bevels, or secondary grind, where it transitions into the primary grind. If the edge relief is too thick it will hinder the edge from slicing as easy as it would with a thinner relief.
 
000Robert said:
The top of the edge bevels, or secondary grind, where it transitions into the primary grind. If the edge relief is too thick it will hinder the edge from slicing as easy as it would with a thinner relief.
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Oh, I get it. Is that what we call the "behind the edge" width? The width of the edge shoulders?
 
Here's why I think it's so difficult for someone to learn to freehand sharpen.

The photo on the left is a 15 dps edge done with a Wicked Edge. It's dead on.

The photo on the right is someone freehanding a 15 dps edge. They get one side at 17 degrees and the other side at 13 degrees. And their stone gets a bit off a couple other places. The difference between the distance at the edge shoulder between a 15 and 17 degree edge is just 0.004 inches on a 0.1 inch edge height. Four thousandths of an inch. Not many people can hold a stone to that precision.

The freehand edge is still sharp. Probably cuts as well. But the edge is not symmetrical. One shoulder is a bit higher than the other. The edge starts to get off center. The apex moves up into the blade a bit. Not a lot, but over time, it becomes a problem. And more metal is removed off the freehand edge. I'd expect this difference to be someone who has a lot of muscle/brain memory. A person new to sharpening will be worse that what is shown.

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