How to "Soup Up" your chakma

Sylvrfalcn

Sylvrfalcn

Joined
Jun 4, 2002
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Want a chakma that'll burnish the edge of even the hardest khukuri? Want to keep everything as "original" as possible? Then pay attention gang, you're going to love this one.

Step 1. Remove old chakma blade from original handle: This is quick and easy, all you need is a pair of vice grip pliers, a propane torch, and an oven mitt/old towel. Clamp the vice gips on the tip of the chakma blade. Set up the propane torch so it can stand stationary, and light it up. Use the pliers to carefully hold the blade over the flame using just the fine tip of the flame to heat the portion of the blade between the plier jaws and the chakma handle. When the laha gets soft enough (you'll see it begin to melt), quickly remove from the heat and use the oven mitt/old towel to gently pull the handle free from the blade (cool the handle immediately under running water and set aside to dry).

Step 2. Make a new blade: Using the old blade as a pattern, carefully grind a new one from an old file (an 8" mill bastard is perfect blade stock for kardas and chakmas). Take care to work slowly and quench often, you want to maintain the full hardness of the file steel for your chakma. Polish your new blade as smooth as possible, nicks and grinding marks will interfere with it's ability to put a really nice edge on a khuk. Don't have a belt grinder, etc.? Me neither, I use various grits of sandpaper on a flat block of wood and plenty of elbow grease.

Step 3. Mount new blade in old handle: Mix up some two part epoxy and set that booger in there. Once it has cured you can polish up the handle nice and Hooflex or "wood chuck" it depending on the material.

And that's it, easy as 1-2-3. You've kept your rig "original", but upgraded to a chakma blade that'll burnish hell out of anything below 64 Rockwell, and yes friends, when struck against a sharp flint it will indeed produce hot bright sparks. A fun and cheap afternoon project that's just plain cool. What next? A full convex ground, file steel, karda blade mounted in the karda's original handle of course.

Sarge
 
Great idea!

BTW. Have you tried rehardening the original once you remove the handle?

? If you left the file's grooves on one side you could
have it for the few times you need to hit the edge hard
to work out bigger mistakes.
.
Reti chakma. Reti karda.
Just the things to go with my Bureti khuk!
:D

Last year I bought a 4" long OAL, 3/16" diameter steel [$9]
sharpening steel from a local restaurant supply store.
Keychain size (ring in 1" brass handle with 3" steel)
Thought that one of these days I'd put on a bigger handle.
?
But to match which khuk?

The 79-cent metal nail files in the grocery checkout
work great for a short time.
If you scrape an edge across them they start to loose 'grit'.
But on surfaces, especially with a lighter touch they're great.
Think of them as carbide sandpaper on a steel backing.
Hmmmmm. Sandpaper....Hacksaw blade.....
 
Hmmm, no I haven't attempted rehardening the original blade, but that's an excellent idea for someone who may lack the skills or equipment to produce a new one. I'll give it a try with the karda when I get to it and post the results

On second thought, scratch that. I just took the original chakma blade to my bench grinder for a spark test, and judging by the color, intensity, and pattern of the sparks produced, I don't think it would be worth the effort. Naturally, it would be foolish to judge 'em all on such a random sampling, but this particular piece does not contain sufficient carbon content to obtain the level of hardness I would want in a chakma. Old files are a known quantity, extremely high carbon content, and since you're starting with a piece that's between 62-64 RC, you can leave as is for a chakma, or temper on down to 58-59 RC for a good knife (karda) blade. Wish I'd been paying attention when those Reti khuks were up for grabs.

Sarge
 
"On second thought, scratch that. I just took the original chakma blade to my bench grinder for a spark test, and judging by the color, intensity, and pattern of the sparks produced, I don't think it would be worth the effort. Naturally, it would be foolish to judge 'em all on such a random sampling, but this particular piece does not contain sufficient carbon content to obtain the level of hardness I would want in a chakma."

Interesting--5160 should have enough carbon, right?

Sooo, are the C's & K's sometimes made of something else?

Or is the carbon getting burned out of 'em? If so, how deeply? Could grinding down a little get to some "good" stuff?
 
Good stuff and thanks. Sometimes kardas and chakmas are made by apprentices which pretty much tells the story.
 
Most of the "as issued" kardas and chakmas are more than adequate, some are truly exceptional, like the set that came with my 18" Sirupati, absolutely flawless in form and function. Still, the only way to know if they're "up to snuff" is to test them and see if they'll do their respective jobs adequately. The accessory tools that came with my fine Shanker made 12" AK were perfectly okay, but through that restless urge to tinker that seems endemic to middle aged males I've made them even better. I now have a chakma that'll burnish even the hardest "sweet spot", and I've tested it on a piece of flint as a fire striker, with excellent results. My karda has a hard, thin (5/32"), convex ground blade with an edge like a scalpel and a point like a hypodermic needle. All that and still retaining the original handles!

Why so much fuss? Because one of the things that first drew me to khukuris was their versatility as a "backwoods tool kit". My very competent little AK now has just that much more capability lurking in it's little black scabbard. I like that.

Sarge
 
Sarge: saw a 10 inch long slightly under half inch wide triangular file I smoothed off with an old, pretty much useless otherwise stone, and sandpaper. Took a while, but not much material and I now gotta figure out what to mount an 8 inch triangular bladed dagger ( that's harder that a cardiologist's heart ) into.
 
I can agree with Uncle. Some chakmas are kinda soft. But on the other hand some of the Blades are kinda hard so can't really blame the chakma there. Probably wouldn't bother with the old chakma just let it ride. Ordered one of those Cerahone stick sharpeners to try out. Not original like a chakma but might tame those hard edges that Bura and some of the others like to put on there khuks.
 
Originally posted by Rusty ...... now gotta figure out what to mount an 8 inch triangular bladed dagger into.


Billiard ball?



Picked up an old butcher's steel at a thrift shop today.
10+ inches of steel, 1/2 inch thick at the handle
then tapering toward the tip.
$2.00
;)
Click to expand...
 
now gotta figure out what to mount an 8 inch triangular bladed dagger ( that's harder that a cardiologist's heart ) into.
Click to expand...

Any good hardwood should work, like ebony, coco bolo, purple heart, etc.. Unless you plan to use it as a parrying dagger for sword fighting, you really don't need a guard. Here's a rough sketch with a suggested shape for the handle.

attachment.php


Sarge
 
Hoghead, where did you get the Cerahone sharpener? What is it made of?
Also, Sarge, (or anyone else) can you tell me how to tell if my chakma and karda are hard enough. I really don't know that much about hardness. I do know where the "sweet spot" is on each of my khuks, because that area takes longer to sharpen. I have heard some say run a file down the edge. When I do, am I looking for a high-pitched sound? I guess I just don't want to do anything that will mess up the edge because of my ignorance. Thanks for the help.

Ben
 
Ben, I'll break it right down to brass tacks, not to insult your intelligence, but for the benefit of others who may be wondering but shy about asking.

A chakma doesn't hone an edge in the normal sense by removing metal. All it does is "burnish" (read that, straighten, align, polish) by ever so slightly moving the metal that forms the very edge itself. To do that properly it has to be HARDER than the metal being burnished or all that's going to happen is cuts and scratches to the surface of the chakma itself. How do you know if it's working? If you move the chakma along the edge with moderate pressure, it should produce a "shinyness" to the edge. A useful trick that someone else suggested is to blacken the edge with a magic marker first. Then you'll be easily able to see how things are going and whether or not you're actually working on the edge itself or the area just back of the edge (which I suspect is many folk's problem when they complain of poor sharpening results). If the chakma is moving the edge metal, it's good to go. If it's not, and all that's happening is the edge metal is chewing up the chakma, then obviously the chakma's too soft to do you any good.

Practice your chakma technique on soft steel knives like old kitchen knives and you'll be getting good results in no time. Once you get "the knack", you'll have no trouble burnishing the edge of a khukuri. If the khuk's edge is too dull for the chakma to bring it back, then it's time for the ceramic rod or mousepad & sandpaper, etc.

Hope I've been of some help, 'cause I really love chakmas and the concept of restoring edges versus regrinding them. Keep a chakma in your kitchen and your kitchen knives will stay sharp and last dang near forever.

Sarge

Sarge
 
Good stuff and thanks.

Pala is a great proponent of chakma use. His theory (and a correct one) is the less metal you take off the longer your knife is going to last. I've seen him spend 30 minutes working an edge with the chakma. No success then a file. No success then a stone. No success then the grinding wheel.
 
If you are trying to reharden a chakman or use another piece of steel to replace it, the way you're going to test for hardness is with a file. What you will do is run afile along the edge, without a huge amount of pressure(hard to describe, as you heat treat more, you get the feel). If it's properly/succesfully hardened, the file will "skate" along the edge without digging in. Feels almost like it's going over glass. This shows that whatever you hardened(knife, axe, chakma, etc), that this piece of steel is fully hardened(or close enough to it), and hence has a high RC testing. In a knife you'd then temper to draw it back. This isn't quite as important on a chakma, as it is not subjected to the strains that a knife is. That being said, I'd probably do at least one low temper at 300F or so(as counterpoint, I do three tempering cycles around 380F or 400F for steel I'm currently using for knives. Makes them softer, but a bit more resilient). Of course then you get into other things such as quench style, etc. If you want more in depth info, heading over to Shop Talk forum and asking makers with more experience is suggested.
 
Sarge, thanks for the brass tacks. It's just what I needed. I did get some scratching on my chakma while working over my BAS, but it did seem to improve the edge. I could tell a difference using the fingernail test. I will check for the shinyness of the edge.

ETP777, thanks for the insight. I appreciate the help.

Ben
 
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