"Fixing" an old machete.

Noctis3880 · May 11, 2011

Okay, so my coworker has been mentioning that he needed his machete sharpened. And being a true knife nut, I insisted on taking up that task:thumbup:. Really, who could resist? An edged tool that needs sharpening to us is like teeth-rotting candy to a morbidly obese kid

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Now the original edge was just awful. It looked to me like the guy tried to chop down a cinder block.

Not having a full-sized belt grinder(I have nowhere to put something that big), I opted to use my Work Sharp Knife & Tool Sharpener. It did fine in resharpening my botched katana, which I dulled due to a poor first attempt at sharpening(tried to sharpen it like a knife, which left me with a near 90 degree inclusive angle).

The first couple of days was slow. It took me a while before I noticed that my P80 belt was too loaded to keep grinding and left me with a near mirror polished edge. After the switch to a new belt it cut with impressive speed, though quickly became loaded up again after a few minutes(I think it's the blade coating). Eventually I removed enough metal(about 1/4 of an inch I believe) for the blade to look almost straight again, and went to the P220 belt before finishing up with the 6000 Micro-Mesh belt.

Here are the pictures afterwards:

The edge still isn't perfectly flat due to the fact that the belt follows any curves unlike a stone. I did try to flatten it a bit on a DMT XC stone, though I didn't feel I made any significant progress. It IS interesting to note that the edge was visibly rusting before my eyes from the water I used, and there were spots covered in rust inside of 15 minutes. Not sure what the steel is, but it rusts even more aggressively than 1095, 5160, and CPM-M4. And that gives me an even deeper appreciation for my nonstainless knives. Even the dust left on the belt seemed to rust, so I threw all those out.

I had plenty of fun with this simple little project even though I wore through a few belts(as well as plenty of dust in my apartment floor).

HeavyHanded · May 11, 2011

Well, I hope your coworker appreciates the work, that's a far cry from how it started out.

You can unclog your belts with a block of natural rubber, cleans em up almost good as new - can be bought at most woodworking shops made for just that purpose. I've also heard you can use a piece of plexiglas or hard plastic and that works well too, but since I use all my belts/paper by hand I've never tried it.

Don't have any pics to share, but I recently was sharpening up a machete to take backpacking and just couldn't get happy with the edge my beltsander (3x21) was producing. I cut them down, glued them to some 3x19 brass plates I had lying around, and used them like a giant bench stone. Kind of surreal using my small knife technique on a 16" machete, but it worked fantastic and the bevels are way more uniform than what I could do with my sander. I did have to use my rubber block frequently to unclog the belts and keep em grinding fast and clean.

HH

foxx · May 11, 2011

You put more time and energy in that machete that it's probably worth. Sure it has some value, to the owner, and maybe now it can actually slice.

I've used a file to convex an Ontario machete, it took a while, so I can appreciate the effort involved. Wish I had one of those work sharps to re-grind another.

jforbush · May 11, 2011

man that is a lot of work you put into that guy.....might want to consider striping off all that black gunk on the rest of the blade....a little time in a media cabinet or some true strip should do the job.

ChapmanPreferred · May 11, 2011

Looks like an improvement. Good effort. Perhaps sometime you could upgrade to a 1"x30" belt sander or at least a bench grinder with some paper wheels put on.

Noctis3880 · May 12, 2011

ChapmanPreferred said:
Looks like an improvement. Good effort. Perhaps sometime you could upgrade to a 1"x30" belt sander or at least a bench grinder with some paper wheels put on.

As I said, I live in a small 2 bedroom apartment so there isn't much space for that. I do happen to have a bench grinder with paper wheels, which would probably have done better in flattening out the blade. Though I wasn't sure I wanted that rust prone dust to be stuck on my wheels.

HeavyHanded said:
Well, I hope your coworker appreciates the work, that's a far cry from how it started out.

You can unclog your belts with a block of natural rubber, cleans em up almost good as new - can be bought at most woodworking shops made for just that purpose. I've also heard you can use a piece of plexiglas or hard plastic and that works well too, but since I use all my belts/paper by hand I've never tried it.

Don't have any pics to share, but I recently was sharpening up a machete to take backpacking and just couldn't get happy with the edge my beltsander (3x21) was producing. I cut them down, glued them to some 3x19 brass plates I had lying around, and used them like a giant bench stone. Kind of surreal using my small knife technique on a 16" machete, but it worked fantastic and the bevels are way more uniform than what I could do with my sander. I did have to use my rubber block frequently to unclog the belts and keep em grinding fast and clean.

HH

Sounds like a great tip to make my belts last longer:thumbup:. Thanks.

jforbush said:
man that is a lot of work you put into that guy.....might want to consider striping off all that black gunk on the rest of the blade....a little time in a media cabinet or some true strip should do the job.

I don't have a media cabinet and I'm not sure what this true strip is.

As for the coating, I don't think removing it is a good idea. As I mentioned before, this steel rusts so fast that you can see it happening. And that's with a polished finish too. So removing the coating would probably turn it into a brown machete inside of a week from the humidity alone.

jforbush · May 13, 2011

got ya...if you are looking at re coating it that is what I do...great job on the cutting edge.

eccvets · May 18, 2011

why not stick the stone wheels back on to the grinder to get a flat edge and then let the paper wheels give that edge a mirror razor edge shine? would have been a hell of a lot fater then using the works trying to get a flat edge which i doublt it will if your using the guides. either way i say one and done; do it right, do it once, save time and your rep as a knife sharpener! take pride in your work and dont accept mediocrity.

oh and i use to live in a 1 bedroom apartment yet i still had a full sized slate pool table in it! dont tell me you dont have enuf room haha!

cramsey3006 · May 18, 2011

That thing looks like an artifact that someone dug up or got from a shipwreck!

1066vik · May 18, 2011

HeavyHanded said:
You can unclog your belts with a block of natural rubber, cleans em up almost good as new - can be bought at most woodworking shops made for just that purpose. I've also heard you can use a piece of plexiglas or hard plastic and that works well too, but since I use all my belts/paper by hand I've never tried it.

HH

cork (used wine corks) and crepe rubber works well - Harbor Freight sells big blocks of crepe for cleaning sander belts pretty cheap.

nevermind35 · May 20, 2011

The edge on those before pics is about the worst I have ever seen! Great job.