Kukri Sharpening

[djweaponx]

I really suck at sharpening. Please tell how not to ruin my new blade when I get it. What is the best way to sharpen and kukri at home the non electric way?

Please inform

 

[Ferrous Wheel]

on the HI site. also, read the Safety First thread here in the cantina.

Keith

 

[firkin]

Ferrous has good suggestions, but you may want to follow them in reverse of the order that appears in his post.

It would be quite difficult to ruin it without electricity I think. It's possible to uglify it. But that needn't be permanent.

Others may correct me but I suspect that the only way to really damage one by sharpening would be to overheat the edge and lose the temper while trying to sharpen with an electric grinder.

You can remove cosmetically undesireable scratches from sharpening by stropping with carborundum paper laid over a somewhat flexible surface, like a mouse pad. This is also a sharpening method. Progress to as fine a grit as you want/need.

It took me a while to get the hang of sharpening at first. If you do a search, there are many threads here on the topic.

Welcome, and let us know what you think when you get it.

 

[munk]

Hey djweaponx; I used to live on the outskirts of LA.

I feel for you. You sure you don't have to register these?



munk

 

[donutsrule]

So when the chakma ends up all scratched by the blade, does that mean it's too soft to do anything good for the blade, or is that normal?

 

[Josh Feltman]

Originally posted by donutsrule
So when the chakma ends up all scratched by the blade, does that mean it's too soft to do anything good for the blade, or is that normal?

I think it's a good sign that the chakmah might be too soft. The chakmah that came with my BAS scratches really easily, and it doesn't work too well.
--Josh

 

[djweaponx]

hahaha good old Cali
No I dont as long as they are clearing displayed when outdoors. Also when out in the woods I just say we are out doing training and tell them I am a instructor. Also I have freinds who are in the force who are usually with me.

 

[donutsrule]

Originally posted by Josh Feltman
I think it's a good sign that the chakmah might be too soft. The chakmah that came with my BAS scratches really easily, and it doesn't work too well.
--Josh

Funny, mine is a BAS, too.
I thought my technique was just really, really bad. But last night I tried a kitchen knife steel and the blade started to sharpen up.

It won't cut thin paper yet (it crushes/rips instead), but now at least it will cut those thicker paper blow-in magazine subscription cards into thin strips.

 

[Rusty]

I'm having good luck sharpening with 1500 grit. Leaves a hair popping edge even without stropping on cardboard. Would anyone suggest going even finer to 2000 or 3000 grit?

 

[Josh Feltman]

donutsrule-- keep in mind that the chakmah will only work if the blade is fairly sharp to begin with. It's more for touch ups than actual sharpening, at least in my opinion. If there is significant dulling, you will probably need to resort to a sharpening stone, ceramic rod, sandpaper on a mousepad, etc.
--Josh

 

[donutsrule]

Originally posted by Rusty
I'm having good luck sharpening with 1500 grit. Leaves a hair popping edge even without stropping on cardboard. Would anyone suggest going even finer to 2000 or 3000 grit?

Are you mounting 1500 grit paper onto a mousepad, or freehand? Or using some other method?

 

[Josh Feltman]

oops--double post
--Josh

 

[Josh Feltman]

Rusty-- I've been using 1500 or 2000 lately. There's not a huge difference between the two, but it is noticeable. I've never tried 3000. If I ever find some I'll try it out.

Donutsrule-- I just lay the sandpaper on top of a mousepad and use a stropping motion. If you do a search in the HI forum for sandpaper and mousepad, you should find a number of posts that describe the technique in great detail. Buzzbait has a great link on sharpening convex edges; it's well worth the read.
--Josh

 

[Rusty]

Thanks Josh. Msy have to get some 2000 and some 3000 in Reno. I use it on a mouspad, but at a low angle and not much pressure.

 

[Mr.BadExample]

Where can I find fine grit sandpaper like you guys are using? The hardware store's finest grit was 400. Is there an online source you can recommend?
Thanks.

 

[BruiseLeee]

Try an autobody store.

 

[Daniel Koster]

Green honing compound on a leather strop is around 5000x. Personally, I've gone the way of Yvsa and now sharpen everything "electrically" - giving most everything a convex edge.

One thing I've thought of trying is this:

Using a fine grit sandpaper held over the chakma.

The chakma is technically for burnishing, but I wonder if you could use it to sharpen as well - since it has a nice flat surface that would easily push through the recurve.

Here's how it would work:

Take a piece of fine grit paper (available at paint shops, metalworking shops, or knifemaking suppliers such as... *see below* ) and cut off a piece small enough to be able to wrap one-and-a-half times around your chakma. Use you thumb against the other flat side to hold the chakma flat against the edge of the knife. Then run it over the length of the edge - maintaining the edge angle you want.

Then, take a piece of leather loaded with rouge and do the same.

Correct me if I'm wrong, but if you were to start with 180 grit and work your way to 1500, and then a strop - you would have a nice edge.


I think I'll try this theory out this evening and get back to you about it.

The nice part of this idea is that you get the benefit of the chakma's flat surface and easy-to-manage size. (versus using a mousepad, stone or strop, etc.)

Dan


[edited to add sources]

K&G has 3M polishing papers that go all the way to 8000x
(1, 2, 3, 9, 15 and 30 Micron)

http://www.knifeandgun.com/catalog/abrasives_186628_products.htm

Texas Knifemaker's Supply has Wet/Dry sheets up to 2000

http://www.texasknife.com/store/s-pages/TKS_MainframeStore.htm
(click on "Abrasive Materials")

 

[Howard Wallace]

OK Dan,

How are you and Yvsa sharpening things and putting on convex edges "electrically" these days?

Belt grinder? Sander?

I also prefer convex edges. The kamis seem to have given up on them since they got their power grinders.

Perhaps if your technique lends itself to production it could be used at BirGorkha to bring back the convex edge.

 

[Daniel Koster]

My technique is not my own, but came from Yvsa - who I'm sure got it from somebody else...

Here are some drawings of my setup:

This is a side by side drawing of the sander/grinder in use. You can see a 2" wheel, a tool rest, and a vertical platen (behind the belt).

I leave the platen attached and grind the edge in the area between it and the wheel above.

This is called "slack belt" grinding. It will always produce a convex edge.

I hold the knife somewhere between 10 and 15 degrees. This produces a longer "bevel" on the edge and if you are good enough - the bevel will go all the way to the top - actually referred to as "zero bevel".

However, for sharpening khukuris, I'd recommend sticking to a convex beveled edge, as to not mar the "magic finish".

Close-up showing the knife pushing into the sanding belt.

A flat ground blade on the left, convex grind on the right.

Close-up of the tips.

Is Bruise taking notes...?!?





Howard,

I don't have the whole story, so I don't know what the deal is. However, I can say that more and more seem to have the "almost convex" edge (meaning donvex beveled edge) - which is a good sign.


Maybe we should have sent a belt grinder with Pala back to Nepal...?

 

[BruiseLeee]

Yeah, I'm taking notes.

I noticed that your version of convex is not as "convex as some of the other drawings I've seen. I get a similar profile, just that they're not all that sharp.

Maybe I'll just special order a crowbar by Bura. It'll save me some time.