"Bending forward" blades.

Ravaillac · May 15, 2005

I've just had a look at Boker's Orca and was wondering:
What's the conventionnal method to sharpen "bending forward" blades (some what like khukris: edge in the inside of the bend)?
I can't see how it can be done properly with a stone, guess that means you have to use ceramic rods, or Spyderco-sharpener-like means. I've never used anything but stones, but these are said not to be good: scrapping metal away, damaging heat treatment, can't be used outdoor, or giving poor results. So that makes those "bending forward" blades not a great design.

Am I missing something ?

Cliff Stamp · May 15, 2005

Ravaillac said:
I can't see how it can be done properly with a stone

Use a small hand size stone (1x4"), or the corner of a large one.

[stones]

these are said not to be good: scrapping metal away, damaging heat treatment, can't be used outdoor, or giving poor results.

Are you talking about a electric grinding stone here?

-Cliff

Thomas Linton · May 15, 2005

Hey Rav, we have a kukri forum here - Himalayan Imports Forum in manufacturer's section. You will find lots of folks there who can help your sharpening issues on "bending forward" knives.

For me, I use sandpaper (various wts. out to 2000 grit) on a mouse pad to keep an edge and ceramic rod to create the edge in the first place.

Joe Talmadge · May 15, 2005

Ravaillac said:
I've just had a look at Boker's Orca and was wondering:
What's the conventionnal method to sharpen "bending forward" blades (some what like khukris: edge in the inside of the bend)?
I can't see how it can be done properly with a stone, guess that means you have to use ceramic rods, or Spyderco-sharpener-like means. I've never used anything but stones, but these are said not to be good: scrapping metal away, damaging heat treatment, can't be used outdoor, or giving poor results. So that makes those "bending forward" blades not a great design.

Am I missing something ?

I think you're talking about recurved blades. You use a ceramic rod, or as Cliff suggested, the corner of a larger stone, assuming the corner is well-done. Basically, you want a stone with a much smaller width than the diameter of the recurve.

Neither ceramic rods nor Spyderco sharpmaker are any more prone to scraping too much metal away or damaging the heat treat than a regular stone. They can be used outdoors fine, and give good results. Like Cliff, I'm wondering if you're talking about something else?

Ravaillac · May 16, 2005

First guys, thanks for your prompt answers and good advice.

Joe Talmadge said:
Like Cliff, I'm wondering if you're talking about something else?

No you're just right. Till now I had always used traditionnal flat stones and "heard" that ceramic-sharpeners/trisharpener-likes didn't perform as well, weren't practical enough etc. Now, as I stated before these were only the rumors I heard. Considering your advice I might give them a try. Do you know one that performs well for outdoor use?

Cliff Stamp said:
Use a small hand size stone (1x4"), or the corner of a large one.

I had though about it, but wasn't sure it was the proper method.

Thomas Linton said:
Hey Rav, we have a kukri forum here - Himalayan Imports Forum in manufacturer's section. You will find lots of folks there who can help your sharpening issues on "bending forward" knives.

Thanks, I'll have a look at it.

Andy_L · May 16, 2005

here's a thread about sharpening kukri on tora forums

http://www.toratoratora.co.uk/forum/forum_posts.asp?TID=407&PN=1

Cliff Stamp · May 16, 2005

Ravaillac said:
..."heard" that ceramic-sharpeners/trisharpener-likes didn't perform as well, weren't practical enough etc.

There are two broad classes of ceramic hones, the first are the slot type :

http://users.ameritech.net/knives/Photo_07.JPG

these are very limiting both in what they can do and they edge they achieve. They have preset angles which can't be altered, and don't create optimal sharpness or durable edges.

The second type are the v-rods, the high end version is the Sharpmaker :

http://spyderco.com/catalog/details.php?product=77

This has two preset angles which can easily be changed by the user by putting something under one end of the base. It produces optimal edge finishes with high sharpness and durability.

-Cliff

Jeff Clark · May 16, 2005

You need to use a hone that is sufficiently narrow to not bridge more than a fraction of the inner curve that you are sharpening. A curved hone is ideal. I have a couple diamond-coated "Sharpening Steels" from Ultimate Edge that I use on better smaller recurved blades. I also like round ceramic rods for finishing the edges. In the past I have used the edges of bench hones or even the sides of thin hone for the same purpose. You can use either the edges or the flats on the triangular Spyderco Sharpmaker rods for most knives. The rods are sufficiently narrow.