Optimizing 3 Cold Steel Kukri Machetes

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kwackster
Posts: 395
Joined: Mon May 15, 2017 8:07 pm

Optimizing 3 Cold Steel Kukri Machetes

Post by kwackster »

Recently i bought several Cold Steel Kukri Machetes.
I had read quite a bit about this specific model, and when i could get a very good deal i grabbed them.

For me these Kukri Machetes have a useful size (they fit inside my daypack), with around 2.8 mm blade thickness they are quite rigid for a machete and certainly not flimsy or wobbly, the steel so far seems well hardened, and the handle fits my hand quite well, while the softer PVC plastic material dampens shock quite effectively.
The factory edges however are only rudimentary, coming with at best a heavily burred or at worst a not even apexed "edge", which is then simply covered in a black bake-on coating.
The backs of the blades are very rough as well, with pieces of burring that were almost sharper than the main edge, and a chequered handle surface that can create blisters with prolonged use.
However with a bit of work & a few simple tools all this can easily be solved, and then the true quality of these very useful blades will come out.

First i used an F.Dick coarse double cut basterd file to completely remove the heavily burred (and most likely burned) apex.
Then i used the same file to make a rough convex shape up to the now flattened apex, followed by an Oberg smooth file to refine the surface up to a new apex, but without creating a burr.
Then i used 3 grits of wet & dry with WD40 as a lubricant on a semi-hard rubber backing to smoothen the convex shape even more, bringing the apex to a burr on 180 grit and refining it through 240 grit and 400 grit.
The burr was then taken off on the Tormek leather wheel with some PA-70 paste.
You can click 2 X on each pic for a bit more detail.

One of the kukri's clamped down with it's heavily burred factory apex already filed flat, but with the coarse +/- 45 degrees factory V-bevels bevels still remaining:

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Starting the new convex edge by filing away the shoulders of the factory edge, then slowly working towards the flattened "apex":

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I think this was actually the first one i did, later this became my tester/user to see how thin i could reasonably take the convexing process.
Almost there btw.

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Number two now done with the bastard file, and starting with number three:

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During sanding on respectively 180, 240, and 400 grit wet & dry SiC and WD40 as a lubricant backed with an old piece of fiber reinforced rubber conveyor belt.
The new apexes fit almost perfectly in the 30 degrees inclusive slot of the Tormek WM200 Angle Master.

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Removing the chequered handle surface with a coarse wood rasp to give it a much more "handpalm-friendly" finish.

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Right after the wood rasp treatment on the right, and one that has already seen several days of use on the left.

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Last edited by kwackster on Fri May 18, 2018 8:24 am, edited 1 time in total.
kwackster
Posts: 395
Joined: Mon May 15, 2017 8:07 pm

Re: Optimizing 3 Cold Steel Kukri Machetes

Post by kwackster »

This is Kukri Machete nr 2 with it's new convex edge (apex at +/- 30 degrees inclusive) and resurfaced PVC handle, currently weighing 504 grams.
Nr. 3 looks the same but it already went to a friend of mine.

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Kukri nr 1 with it's new convex edge (apex also remaining at +/- 30 degrees inclusive) and resurfaced handle, but with a convexed area that is a bit thinner & wider compared to nr 2 and 3.
The slope on this one starts higher up the blade, and it currently weighs 474 grams.

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A few more pics taken in the woods.
So far it has proven to be indestructible, even with all out chopping of many types of green woods in various thickness up to small trees with a diameter of 15-20 centimeter.
No catastrophic edge failures or even rolling, while binding in thicker woods has diminished due to the thinner convex.

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Last edited by kwackster on Fri May 18, 2018 8:24 am, edited 1 time in total.
gravknife
Posts: 1491
Joined: Fri Dec 11, 2015 9:34 pm

Re: Optimizing 3 Cold Steel Kukri Machetes

Post by gravknife »

Kwackster

That Cold steel khukuri is a beauty.
I like the handle alteration ,the last thing you want is one of these slipping out of your hands they are dangerous from all angles.


I have recently been lucky enough after many years to get a cheap ww2 issue British khukuri and it would be very grateful for one of your sharpening processes to bring it back to its former glory.
I don't like messing with war artefacts so it would need your talent and knowledge really , but these knives do beg to be sharpened and then used.

I think these are a fantastic bushcraft knife and even deadlier weapon ..They are great shelter builders and then even perform the smaller tasks like food chopping and kindling well .
Pick yourself up a Karda and chakmak for finer skinning and smaller work and fire lighting and maybe make a sheath to include them .

My other khukuris have a similar grind to the one you created .The one furthest right on top picture is best for its great balance and heavy weight and chopping abilities ....it was hand made in Ghum Darjeeling by ajab Singh in the early 1900s...the white bone handle is a parade khukuri ,light and fast for combat .....both have your grind type .

Great sharpening tips once again ,i would like the ww2 like your Cold steels eventually ....thanks for posting them .


gravknife
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kwackster
Posts: 395
Joined: Mon May 15, 2017 8:07 pm

Re: Optimizing 3 Cold Steel Kukri Machetes

Post by kwackster »

Hi gravknife,

It's not so much the chances of slipping why i resurfaced the kukri machete handles but because of the real possibility of skin damage and/or blisters due to the chequering which does not belong on the handle of a large blade like this imo, which shifts around in your hand quite a bit while working with it.
The PVC material itself however dampens shocks quite nicely, and now with the much improved handle comfort these blades are a joy to work with.

Next to these Kukri Machetes i have a good quality reproduction kukri as well, a Camping Kukri from Tora Blades in England that i bought in 2009 and which also sees regular use in the woods surrounding my home town.
Very good quality i might add.

Cold Steel Kukri Machete & Tora Blades Camping Kukri:

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The two large kukri's on the right that you show in your post seem to be the real deal, and i'm sure they would shine when given a crisp convex edge.
I especially like the dui chirra model with the white handle, from the pics it looks indeed fast & lively in the hand.
Now i've never sharpened a true vintage kukri like yours before, but i would make sure to tape everything off outside the edge area to avoid making any scratches in the rest of the blade and to preserve that nice patina that took all these years to develop.
It would probably make for a very nice contrast with a bit of a polish on the edge.
Last edited by kwackster on Fri May 18, 2018 8:25 am, edited 3 times in total.
kwackster
Posts: 395
Joined: Mon May 15, 2017 8:07 pm

Re: Optimizing 3 Cold Steel Kukri Machetes

Post by kwackster »

We had something of a storm a few weeks ago, and many forest trails are still littered with broken branches and/or blocked by fallen over small trees like these 3 birches.
The modified Kukri Machete dealt fast & easy with both the de-limbing as well as chopping up the main trunks into moveable sizes.

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Last edited by kwackster on Fri May 18, 2018 8:25 am, edited 1 time in total.
kwackster
Posts: 395
Joined: Mon May 15, 2017 8:07 pm

Re: Optimizing 3 Cold Steel Kukri Machetes

Post by kwackster »

About twice a week we like to take a hike in the forests surrounding our home town, and each time we walk between 7 and 10 kilometers. (about 4 to 6 miles)
During that time i use any of my choppers to keep the walking trails clear from overgrowth, ranging from small green branches up to small trees, most of them green, some dried.
The last few weeks i've been using the modified Kukri Machete for this job, and i've been trying out different edge finishes to get a better idea of how this influences both the performance as well as the edge retention of the 1055 steel.

The first edge on this machete was finished on 400 grit wet & dry with WD40 as a lubricant, while burr removal was done on the Tormek leather wheel with some Tormek paste.
At the start of a trail this edge was armhair shaving sharp on skin level, and when we returned home it was copy paper slicing sharp.
I could keep the edge at this level of sharpness for 2 other hikes by stropping it after cleaning on a piece of MDF with some 1.0 micron diamond paste.

Before the fourth hike the edge was resharpened on a Rubber Wheel coated with 230 grit diamond powder using wax as a lubricant/coolant, and deburred on a Paper Wheel with 1.0 micron diamond compound.
This provides for a noticeable finer edge (yet still a bit toothy), and at the beginning of our hike the edge was treetopping armhair, and when we returned home the edge was scrape shaving armhair.
After one more hike and using only the piece of MDF with 1.0 micron diamond compound the edge is currently still at that level of sharpness.
Maybe after the next hike i will resharpen it again to a bit finer finish and see how that does.

I do know it's all a bit over the top for a simple machete, and in the end i might just settle for file sharpening, but i thought i'd share.
kwackster
Posts: 395
Joined: Mon May 15, 2017 8:07 pm

Re: Optimizing 3 Cold Steel Kukri Machetes

Post by kwackster »

Another bit of info i learned only yesterday: these machetes are made by Lasher Tools, a South African company.

http://lasher.co.za/
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