Finishing a Chakma

K

Kazeryu

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Nov 7, 2005
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Well, my chakma was pretty beat-up already. I had tried using the edge of the chakma for burnishing before reading the threads about 'wiping' with it. I didn't notice it until I went to put away the chakma, but I had cut millimeter-deep gouges in a number of places along the edge, and gotten some deep scratches across one face. This baby was SOFT.

Anyway, I figured since it was pretty useless to begin with (being so soft) and even more useless now (full of teeth) I thought I would test out my theory about the soft decarburized shell. I reckon that if most khuks need a good solid sharpening or two to reveal the 'good stuff', then maybe chakmas are the same way. A lot of people find the chakmas too soft, and maybe it's only because they've never 'sharpened' one.

I'll keep updating this thread as I get better tools and get further along, but here's what I've done so far.

I have a box of needle files I got from my grandfather - they're almost certainly older than I am, but pretty good quality. Some kind of tool steel or something, but definitely iron based. Not diamond, not ceramic or anything fancy like that. Anyway, I grabbed a medium-coarse file and started working on removing the outside 'shell' of the chakma, and boy was I surprised.

Both sides of the chakma turned out to have concave - NOT CONVEX - sides!:eek: It wasn't anywhere near flat!

It was also soft like butter. Just a coupla minutes of filing pulled off close to a millimeter of steel on the outside edges, and I still don't have a flat-surfaced chakma. Spent a few seconds filing the spines/edges of the chakma, too, to get those millimeter & deeper gouges out -- they're all gone now. I removed a heck of a lot of steel using a plain old metal file. :eek:

I finished off with a much finer grind file and then some unknown sandpaper that was probably in the 150-220 range. I think it's still way too toothy to use for burnishing. I'll need to wait until I can get a diamond hone or at least some higher grades of sandpaper to finish it up.

I'm pretty sure I've gotten down to some harder steel - the steel removal slowed down a lot more than just the increasing surface area would account for.

I would like to get this baby either flat or convexed before burnishing with it though. I was just amazed at how soft it actually was. I'll post a pic showing the grinding when I get home.

What are your reactions to this?
 
here are some pics...

in the first one you can see from the grinding that the chakma had a concave surface :(



I also filed and sanded some grooves into the butt of my kharda so I could tell the two apart without unsheathing them.





I noticed people have looked at this thread without responding... even if you just think I'm plum crazy, let me know what you think...:confused:
 
Sounds like a decent idea and theory. I have to wonder, however, if the concave was intentional. Since you want a convex khuk, would the burnisher ideally present a concave burnishing face? I dunno. Or maybe that's silly. I like the idea about the "good stuff" being down low. Kinda makes sense. In addition to helping with burnishing, a harder chakma could also strike flint better.

Cool stuff! :D

Chris
 
I think you have too great craftsman skills to mess with the (to me) almost universally crappy steel on the chakmas on khukuris made by almost any one.

But, that said, you sure as hell could make something out of hardened steel to work to burnish the edge. Chainsaw file, a needle file without Grandpa's heritage, small steel knife...almost anything.

Nice images.

Thank you.
 
Yeah I use the shaft of a screw driver to burnish. I use my wife's icy cold gaze to quench the edge.
 
I have refinished a couple of chakmas, and found the same thing - soft steel over a hard core.
You can find fine grit silicon carbide paper in the auto-supply store's paint department.
 
Betcha both a shiny nickel that the entire thing is crap steel.

Unless you are heat-treating it while you grind it down.
 
well, we'll see. either way, it is proving to be an interesting project, and will give me some experience in putting a high polish back on steel - without a buffing wheel.

Even if I don't wind up with a good burnisher, I will still have had fun and have the pride of having made the attempt.
 
I'll see Kis' nickel and raise y'all a dollar. Did a bit of research and testing of my own. Of the half dozen or more chakmas I've put to the test, all lacked sufficient carbon content to permit proper hardening. I've ground 'em, hammered 'em, heated 'em cherry red and quenched 'em in a variety of mediums. Same result, can't harden mild steel to the "brittle hardness" you can high carbon.

Still, I love my khuks (which themselves are made of absolutely top notch steel) and try to keep them as original as I can. That's why I try my best to retain my original karda/chakma handles and just grind new blades for them.

The original chakma blades can be removed fairly easily by carefully heating the metal with a propane torch. When things get hot enough for the laha to let go, simply yank the blade out of the handle with a pair of vice grip pliers.
Grinding a new blade from an old metal cutting file is a fairly straight forward proposition, just take care not to burn the temper out of the metal when grinding. The tang for your new blade will be kind of small/skinny, and should not be left full hard or it might snap. Not a problem, wrap the blade in a wet rag, and using the propane torch again heat the tang until it turns blue, or at least purple, indicating you've "burnt the temper" from it, rendering it now soft and not brittle. Mount the new blade in the old handle with a good two part epoxy, and you're off to the races.

Sarge
 
bigjim said:
Yeah I use the shaft of a screw driver to burnish. I use my wife's icy cold gaze to quench the edge.
Click to expand...

Yup, i know that 'you never buy anything useful, like diamonds, do you?' look. my resulting 'yes i do, just bought a neat fine diamond sharpener' has resulted in 2 divorces so far, heading for three.
 
I only have one Chakma out of all my khuks that is really hard. It came with my first khuk, a 20"AK back in 1999. I use it on my other khuks all the time. Plus it is HUGE at about 6-7" long: which is much more practical IMO than some of the teeny tiny ones that came with my smaller khuks.

I have found that some of the others are hard enough to burnish the soft areas of the blade, but they skate right over the sweet spot.
 
Here's three of my chakmas,
Top one is made from scratch, with handle done in rosewood and brass, bottom two are "retrofitted" originals from a Pen Knife and a 12" Siru.

The file blades, left at full hardness of around 64RC are some burnishing machines. Through trial and error I've arrived at the practice of leaving one edge of the chakma with minute longtitudinal scratches (put there by a diamond hone) that make it sort of "toothy" (absolutely the bomb on kitchen knives), and the other edge gets polished glass smooth for serious khuk edge burnishing.

Since you don't have to worry about bevel angles, blade geometry, and the like, grinding a chakma from an old file is pretty much a "Skill Level 1" project. Give it a try, you won't be sorry.:D

Sarge
 

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ah, but first I would need an old file. ;)

I'll see what happens with the chakma I was 'issued', and maybe try the old recycling trick a bit later on. I still need to finish the wood somehow, before the winter weather gets to it. The chakma isn't the first knife priority at the moment.
 
neat stuff. The list of things I need to look for the next time I'm at a hardware store keeps getting longer and longer!
 
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