Thu Oct 25, 2012 7:25 pm

Hi Mark,

I can get a burr on both sides of my konosuke but I cant get the kono as sharp as ootb. Using chosera stones 1k to 5 k. is my angle to steep? I watch your videos but just cant get it to where it should be. thanks mark.

I can get a burr on both sides of my konosuke but I cant get the kono as sharp as ootb. Using chosera stones 1k to 5 k. is my angle to steep? I watch your videos but just cant get it to where it should be. thanks mark.

Thu Oct 25, 2012 8:25 pm

Use pennies to establish the angle you're sharpening at.

On a 2" wide knife, every 3 pennies high the spine is off the stone with the edge touching the stone is roughly 5 degrees per side.

So if you sharpen a knife with the edge 3 pennies high, you'll have a 10 degree total edge. Not sure which Konosuke you have, but 10 degrees is kind of where I start with all my knives. If it fails, I increase the total angle until it doesn't.

Hope that jibber jabber makes sense.

On a 2" wide knife, every 3 pennies high the spine is off the stone with the edge touching the stone is roughly 5 degrees per side.

So if you sharpen a knife with the edge 3 pennies high, you'll have a 10 degree total edge. Not sure which Konosuke you have, but 10 degrees is kind of where I start with all my knives. If it fails, I increase the total angle until it doesn't.

Hope that jibber jabber makes sense.

Fri Oct 26, 2012 12:51 am

Go to a finer grit. The odds are that - if I remember correctly - the finish is a natural stone finish on your knife, so consider a finer grit synthetic or natural stone finish or even stropping with something like 0.75 micron CBN (24k) or finer. An ideal choice in a synthetic stone would be the 15k Nubatama, which is competitive with many high end natural polishing stones or something like a Yaginoshima Asagi in a natural finishing stone.

My comments supplement Adam's advice regarding basic angle control. Here depending on how much use your knife has had, you may need to thin the edge a bit too.

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Ken

My comments supplement Adam's advice regarding basic angle control. Here depending on how much use your knife has had, you may need to thin the edge a bit too.

---

Ken

Fri Oct 26, 2012 1:30 pm

Hey Adam,

I recently purchased a book about sharpening and knife skills and I found an interesting mathematical formula that describes a method for determing the height of the spine off of the stone that is required to achieve a particular angle.I have a feeling that most of you are already aware of it and I'm behind the times on that front.

It's sine and somewhat complicated (for me) however there is nifty table that shows it all.

For example, if you want a 20 deg angle on a knife that is 3 inchs wide at the heel, you raise it 1 inch (or 7 quarters I believe, I don't have the book in front of me)

However math is math, it's logical and folks like Ken will understand the formula while looking at it, playing chess and sharpening a Yanagi at the same time.

As I said it is probably old news but if anyone is interested I will copy the table that shows the angles/heights etc. One does not have to understand the math, just follow the table. Not necessary probably for folks who sharpen similar knives all the time, the 3 pennies for 5 deg is perfect.

Pete

I recently purchased a book about sharpening and knife skills and I found an interesting mathematical formula that describes a method for determing the height of the spine off of the stone that is required to achieve a particular angle.I have a feeling that most of you are already aware of it and I'm behind the times on that front.

It's sine and somewhat complicated (for me) however there is nifty table that shows it all.

For example, if you want a 20 deg angle on a knife that is 3 inchs wide at the heel, you raise it 1 inch (or 7 quarters I believe, I don't have the book in front of me)

However math is math, it's logical and folks like Ken will understand the formula while looking at it, playing chess and sharpening a Yanagi at the same time.

As I said it is probably old news but if anyone is interested I will copy the table that shows the angles/heights etc. One does not have to understand the math, just follow the table. Not necessary probably for folks who sharpen similar knives all the time, the 3 pennies for 5 deg is perfect.

Pete