Insanely Sharp Coconut Machete

[rang3]

I'm wondering how to get a machete or cleaver sharp enough to slice straight through a coconut as shown in these videos:

[video=youtube;B1Q8B03Lmus]https://www.youtube.com/watch?v=B1Q8B03Lmus[/video]

[video=youtube;SLPwtJ43xr4]https://www.youtube.com/watch?v=SLPwtJ43xr4[/video]



I have watched countless coconut-cutting videos and this is extremely rare.

Is it the edge angle, blade thickness/smoothness, grit used/refinement, or some other factor that allows for this? What kind of sharpening protocol are these gentlemen most likely using to achieve this?

 

[Panotaker]

I'm willing to bet that if those guys hand you their machete, you won't be able to cut a coconut in half, your fingers maybe, but not the coconut. I'm sure their machete is sharp, but it's probably more technique than anything else.

 

[bonafide]

It's technique. I lived in central/south america for 3 yrs. Everyone carried a machete. Some of the things people could with them were amazing. My favorite thing, was to watch 3 guys mowing a lawn with nothing but a small crooked stick and a machete. CrAcY skills.

The catinas (bars) in the rural areas would have a wall outside, for everyone to lean their machete against. They were not allowed inside.

 

[jackknife]

That guy knows how to sharpen a machete! I bet nobody messes with him.

 

[bgentry]

I don't know much about coconuts, but I noticed that all of these were green. That means they are young (immature) coconuts, as compared to the fully ripe brown ones. So they are softer, which makes them easier to cut.

Brian.

 

[Jason B.]

It's all about the speed.

 

[rang3]

Hmm, most of you seem to be saying technique/speed so you must be (at least partially) right, but I have tried this at near full speed/force with a brand new cleaver (on young green coconuts) and it doesn't even come close.

I have watched dozens of similar characters cutting coconuts on youtube and those are the only two slicing clean through the coconuts. The coconut husks are a hell of a lot tougher than they look.

 

[fmendez]

Sharp machetes are common in the Caribbean, and if you think coconuts are tough try sugar cane from sunrise to sundown. Missing toes are common since the cane has to be cut low to the ground often without shoes.
Among the guajiros of Cuba and jibaros of Puerto Rico, scars in the arms are seen due to disagreements settled a machetazo, a good reason not to bring them into a bar.

 

[me2]

Those guys probably learned to cut coconuts about 3 days after they could walk. Aside from that, a careful examination of the edges would likely show a much lower bevel angle than usually seen/recommended here. A 7 to 12 degree per side bevel is likely, where most recommend 15 to 20 here. There also may or may not be a small secondary bevel up to maybe 15 degrees per side. It likely won't be a distinct transition, but blended back smoothly from 15 into the lower angle above the very edge.

 

[bgentry]

Two more thoughts:

1. A machete is way longer than a cleaver, so the end of it is going to move a lot faster and therefore have more energy to get the job done.
2. A friend of mine in South Florida said that he used to hire guys from the Caribbean to do lawn work with him. He said that they sharpened their machetes by stabbing the point into a tree, bending the blade a bit, and then using a file on each side of the edge *while* the blade was under bending tension. My friend said they got extremely sharp edges that way and he thought the bending technique was the reason.

Trying to think about it I can't come up with any good reason that would make a difference, but that doesn't mean it doesn't work!

Brian.

 

[Obsessed with Edges]

Two more thoughts:

1. A machete is way longer than a cleaver, so the end of it is going to move a lot faster and therefore have more energy to get the job done.
2. A friend of mine in South Florida said that he used to hire guys from the Caribbean to do lawn work with him. He said that they sharpened their machetes by stabbing the point into a tree, bending the blade a bit, and then using a file on each side of the edge *while* the blade was under bending tension. My friend said they got extremely sharp edges that way and he thought the bending technique was the reason.

Trying to think about it I can't come up with any good reason that would make a difference, but that doesn't mean it doesn't work!

Brian.

What jumps to my mind, on the bending of the the blade, is that it'll reduce the likelihood of the blade's edge being rolled or burred on the edges/corners of the file (assuming they file on the outside arc of the bend). It keeps the point of contact on the 'flat' of the file, which distributes pressure. I've thought about this every time I've used a 'flat' ceramic or similar stone which has slightly upturned edges, which will roll or burr an edge in a single pass due to highly-focused pressure, and severely limits how refined the blade's edge can get.

Slightly warped, curved, bent or 'crinked' blades will always have some troubles on flat stones/hones, because from one side anyway, the blade will be bent/curved over the edges of the hone, limiting contact to those portions. I could see how a long, thin & relatively soft-steeled blade like a machete would have troubles in sharpening, if the primary contact were along the edges of the hone/stone being used.

Agree with other's comments about the thin geometry of the edge being the difference-maker in chopping. Thin geometry & low edge angle always trumps anything else, in terms of ease of cutting.

Also agree about the 'softness' of the green coconuts making at least some difference; this can be seen in the ease by which the coconuts are lightly picked up and held on the edge of the recurved blade, in the 2nd video. They'd have to be somewhat soft to pull that off.

(Wonder how many fingers have been lopped off, in seeing these coconuts being sliced/hacked/chopped while in-hand. Makes me shudder a bit to watch it... )


David

 

[rang3]

Sharp machetes are common in the Caribbean, and if you think coconuts are tough try sugar cane from sunrise to sundown. Missing toes are common since the cane has to be cut low to the ground often without shoes.
Among the guajiros of Cuba and jibaros of Puerto Rico, scars in the arms are seen due to disagreements settled a machetazo, a good reason not to bring them into a bar.

Any idea of typical sharpening methods, edge angles, etc. in those places?

Those guys probably learned to cut coconuts about 3 days after they could walk. Aside from that, a careful examination of the edges would likely show a much lower bevel angle than usually seen/recommended here. A 7 to 12 degree per side bevel is likely, where most recommend 15 to 20 here. There also may or may not be a small secondary bevel up to maybe 15 degrees per side. It likely won't be a distinct transition, but blended back smoothly from 15 into the lower angle above the very edge.

Damn, that's really low! Haven't seen 7 to 12 degrees recommended for much other than straight razors.

Agree with other's comments about the thin geometry of the edge being the difference-maker in chopping. Thin geometry & low edge angle always trumps anything else, in terms of ease of cutting.

Is there more to "geometry of the edge" than "edge angle"? What kind of edges - angle and bevel-type - are we likely looking at with the machetes above, and what is the best sharpening method to achieve these awesome results?

Also, how much is general blade thickness and polish coming into play?

 

[Panotaker]

Growing up in Puerto Rico over 50 gears ago, my dad sharpened his machete with a grinder, then a file, then finished it up on a flat sharpening stone. The machetes came out razor sharp. I don't remember him doing the one hand coconut cut trick though. Only reason I remember is that he had a manual grinder that had a handle on it that someone had to turn to get the grinding wheel spinning. Guess who that person was.

 

[Obsessed with Edges]

(...)Is there more to "geometry of the edge" than "edge angle"? What kind of edges - angle and bevel-type - are we likely looking at with the machetes above, and what is the best sharpening method to achieve these awesome results?

Also, how much is general blade thickness and polish coming into play?

With these blades, I doubt polish plays into it much. I'd bet the methods used to sharpen them are likely pretty simple, maybe even crude, by our standards (files, simple or coarse natural stones, sand on wood, etc). I think it's mainly the thin blade stock and very low-angle honing that's making the difference here. Probably some convexity to the edges, if sharpened by hand; but I'm sure it's very shallow, if so. Any convexity that smoothes or eliminates the hard shoulders of a V-bevel could be helpful in reducing drag of the blade through the material (great for cardboard cutting, BTW); and a polished, thin convex can be scary-slick.


David

 

[stitchawl]

With these blades, I doubt polish plays into it much. I'd bet the methods used to sharpen them are likely pretty simple, maybe even crude, by our standards (files, simple or coarse natural stones, sand on wood, etc). I think it's mainly the thin blade stock and very low-angle honing that's making the difference here. Probably some convexity to the edges, if sharpened by hand; but I'm sure it's very shallow, if so. Any convexity that smoothes or eliminates the hard shoulders of a V-bevel could be helpful in reducing drag of the blade through the material (great for cardboard cutting, BTW); and a polished, thin convex can be scary-slick.


David

Very true! Living in Thailand, I see this sort of coconut cutting going on in every street market, especially in the tourist areas. I have several different styles of machetes myself, bought just because I like 'em, not because I need them. The locals do sharpen them with files, and leave a very rough edge. Some of the larger machetes also get a touch-up on stones that look more like shoe boxes, seem to be about 400 grit or there about. The speed that the machete moves is the real key. When I try to cut a green coconut, I don't come close to just lopping off a top unless I have the coconut anchored firmly. I'm too chicken to try a full-speed slice while hand-holding. Too easy for the blade to skate off the side!

In the tourist venues, the sellers make several side cuts to narrow the top, then make 4-5 vertical cuts down, and lift out a 'plug' about 2"-3" across, drop in a straw, lay the plug back on top, and hand it to the tourist to walk with while drinking.


Stitchawl

 

[Squashfan]

Doubt either machete is that sharp. They might shave arm hair but Jason is right, speed is king.

 

[FortyTwoBlades]

Those guys probably learned to cut coconuts about 3 days after they could walk. Aside from that, a careful examination of the edges would likely show a much lower bevel angle than usually seen/recommended here. A 7 to 12 degree per side bevel is likely, where most recommend 15 to 20 here. There also may or may not be a small secondary bevel up to maybe 15 degrees per side. It likely won't be a distinct transition, but blended back smoothly from 15 into the lower angle above the very edge.

Yup. Probably a very thin angle and well practiced technique.

 

[Faiaoga]

Yup. Probably a very thin angle and well practiced technique.

Right on. I'd like to know where the video was made. The young man does a very nice job showing how a piece of the green coconut husk can be used to scrape out the soft, jelly-like material from the inside of the drinking nut. In Samoa,, this soft material is used as baby food.

 

[singularity35]

Not that sharp. As mentioned already, low bevel angle, speed, and young coconut. That wouldn't work with mature nuts. Those have much tougher husks and a very hard inner shell. Use those on mature nut, and you'll have a.lot of edge damage. BTW, I grew up in my mother's coconut farm so I know more than a little about coconuts and harvesting and eating them.

 

[rang3]

Right on. I'd like to know where the video was made. The young man does a very nice job showing how a piece f the green coconut husk can be used to scrape out the soft, jelly-like material from the inside of the drinking nut. In Samoa,, this soft material is used as baby food.

Trinidad