Just ordered a 14" Mutiny...

Kailash Blades said:
Ah that's awesome to hear! The convex is for sure the way to go on these wood chopping blades- sinks a lot deeper for the same strength. I've not had much luck with the sandpaper/pad combo but I'm glad you've had a win :)
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Yes, I used a kneeling pad off of Amazon to keep the paper still and provide a little bit of give and 400-600-800 wet dry sandpaper.

How do you sharpen?
 
I use ceramic sharpening rods and leather to touch up and hone. For big damage I just knock the corners off a touch with a hard abrasive then leave it be. Eventually it'll all smooth out with time :)
 
Honestly, I've been using a honing rod and/or strop and that's actually been enough so long as it isn't used to the point of actually being dull. Just a touch up after use.

Just because it seems like a good place to bring it up: is a ceramic rod going to ruin the convex edge?
 
I don't believe that a ceramic rod will ruin the convex edge. Ceramic rods both burnish and abrade. They're used quite loosely across various angles and only contact at a single point at once. I feel like this will maintain a level of convexity. It could become a little less convex, could become a little more convex but it's gunna stay convex. Stropping will do the same, but with less of a tendency to alter pre existing geometry.
I agree that touching up often is the way to go. Super quick, super easy and it feels like you can do it forever.
 
Good to know! I really want to make sure I keep a proper edge.

Also I have to correct that I use a burnishing rod for most of my touch-ups. I try not to go abrasive if I don't need to.
 
Ah yep a smooth hone. I think the jury is still out on the effects that burnishing has on the microstructure of stel at the apex. I saw some writing recently suggesting that burnishing smooshes steel into place but also removes it through adhesion. So long as the steel at the apex isn't getting smooshed around over and over again and becoming progressively weaker then it should be fine. I like the additional speed of having a fine abrasive working at the same time, as well as the guarantee that there's fresh, uncompromised steel continually being exposed at the apex.
Maybe if you keep an eye out you might see some similar sharpening tools available on our site soon 👀👀👀
 
Kailash Blades said:
Ah yep a smooth hone. I think the jury is still out on the effects that burnishing has on the microstructure of stel at the apex. I saw some writing recently suggesting that burnishing smooshes steel into place but also removes it through adhesion. So long as the steel at the apex isn't getting smooshed around over and over again and becoming progressively weaker then it should be fine. I like the additional speed of having a fine abrasive working at the same time, as well as the guarantee that there's fresh, uncompromised steel continually being exposed at the apex.
Maybe if you keep an eye out you might see some similar sharpening tools available on our site soon 👀👀👀
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I will have to look into that. I'm not pushing hard enough that I should be doing much smooshing. Essentially, I use it the exact same way one might use a Chakmak with a bit of "scrubbing" on the edge. As I understood it, a burnishing rod realigns the edge as opposed to removing material which may be what you're talking about? I'm no sharpening pro.

I'll be on the lookout for new gear!
 
Yeah we're sort of on the same page! Realigning I would consider smooshing. It would be called plastic deformation by an engineer, which is a bending that causes permanent change. Bending that springs back is called elastic deformation. Whenever plastic deformation takes place in a blade steel it changes the microstructure of the steel. New stresses form, little gaps open up, maybe strain is released that was contributing to hardness. I'd guess that overall in most blade steels it would become more brittle. I'm sure you've bent thin metal over and over until it tears- same kind of thing.

If this was all that was happening it would be concerning for a chopping knife. Our apex needs to be very stable (hard and tough) to hold up to these kinds of forces. This kind of degradation could lead to edge failure through chipping or rolling and then this damage can act as propagation sites for cracks or larger rolls, chips etc. It also likely reduces edge holding capability (max sharpness and edge life) in slicing and carving etc.

However the reading I was doing recently suggested that such polished knife steels and burnishing tools were not just realigning the steel but also removing a small amount of steel through adhesive wear (steel sticking to the hone and pulling away). This makes me feel a bit better about the process- that it also removes and exposes fresh, healthy steel to do work rather than just recycling and continually degrading the older stuff.

Take care,
Andrew and the team at Kailash
 
I was thinking that the harder steel "scrubbing" the softer steel would have more of a polishing effect a bit like a strop but, I could be wrong(there seems to be a fair bit of debate on the topic). I only use light pressure with a burnishing rod so maybe "scrubbing" is too aggressive of a term. Certainly no where near the force used to fix a rippled or rolled edge.

I can see how if realigning is happening, you could end up work hardening the edge but do you think that on the scale at hand that it would be much different than creating a burr as I understand many knife edges have? Never heard of the adhesion though so that's something worth looking into. Perhaps I'll switch and do more stropping unless/until more aggressive methods are needed, a bit like I treat my carving tools.

Part of me thinks it should be fine given that the chakmak is often paired with these blades but that could be more for field expediency/convenience rather than what is truly best or proper. Unfortunately, I haven't had any hard working blade long enough to say but I would assume that like anything, only take off what you need.
 
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Typically polishing is used to describe going up to increasingly high grit abrasives to produce a smooth, uniform surface. By this definition strops do polish- they're loaded up with very fine abrasives and this produces a refined bevel and crip, fine edge. this is in contrast to a polished knife steel which doesn't operate through abrasion. While it leads to a smooth, polished surface this is achieved through adhesion and "surface smearing" type operations. Here's a video of a burnishing tool on a lathe.

What a polished knife steel is doing is often described as "realigning the edge" but as you've pointed out they are generally used with light force and don't move metal around at a scale that is visible to our eyes. EG if you get a roll from hitting a bone with a kitchen knife a steel isn't going to straighten that up. The work that is happening is on a very small scale and is difficult for us to inspect visually. Burnishing works by focusing pressure onto a very small area- from a hard round steel to a very small area on a slightly convexed bevel. As a result you don't need to apply much pressure- the force is multiplied naturally in much the same way that a knife edge cuts through things.

I think that the comparison between the burr and a weakened apex is a valid one. However I think that the benefits of a quick finishing pass on a strop are widely recognised. It is an issue for final sharpness as well as edge holding capability and stropping makes a big difference. I'm of the belief that the difference is even greater for chopping blades and apexes that see high impacts than on slicey edc blades. If there is a weakened apex formed through burnishing it is not so easily removed- there is no quick post-sharpening step that restores performance short of resharpening with abrasives.

I think that the chakmak is a handy, long lasting, simple to use sharpening tool that brings a khukuri up to working sharpeness quite quickly. A chakmak (and similar burnishing tools) will likely demonstrate a smaller gap in performance vs abrasives on simple high carbon steels, particularly on the lower carbon side and with chunkier geometry. A khukuri is a good fit. However I think that modern expectations of sharpness levels, edge holding and broader cutting performance in general are getting higher and higher and abrasives are more likely to be able to meet that expectation.

Take care,
Andrew and the team at Kailash
 
Great to hear!
We could make one thinner in stock and also a little bit thinner in the grind but the mutiny is already pretty close to the limit of what we consider practical for an outdoors blade. There's not much more we can trim without it getting a bit risky for big chopping impacts
 
I’ve been doing a good amount of clearing my hunting grounds. There are fresh saplings that are as thin as a pencil (or thinner), most are 2 fingers thickness some up to wrist thickness. 2 fingers and up are easy, smaller is near impossible to get down. Any recommendations? Blade easily whittles paper
 
How densely packed are these pencil thickness saplings? If they're pretty sparely packed it may be worth using your off hand to hold and lift the sapling to apply a little tension. You can also try push cutting through with the waist rather than swinging.
If they're very densely packed then it sounds like machete work- a longer, lighter blade with more tip speed will help to get through the flexible stuff before it has a chance to bend and move out of the way. You can consider modifying your technique for these very thin ones by trying to hit closer to the tip and focusing on maximum speed more than power. For me sometimes that looks like a small karate chop with lots of "snap cutting" in the wrist. Cutting at 45 will help also.

In terms of other blades that are better suited to the task we don't have much that's more machetelike than the mutiny. We try to stay away from the far end of that utility spectrum- very thin, long knives are difficult and expensive for us to make with out techniques and we are competing against mass manufactured, stamped, springy 2mm machetes that are far cheaper than we can offer. One blade that sticks out in my mind that would be better sutied than the mutiny would be our ginuntings. These are lighter, longer and generally a little leaner vs the mutiny. I think the slight inwards curve near the tip also helps to grab and snick through thin stuff. The pictured blade is 16" but we could go longer for sure.
 
yeah they can certainly go quick
I think the cross section is a little thick vs the mutiny though. If we did a slimmed down full flat grind chitlange (no fuller) that would be a performance bump vs the mutiny in this application. The chitlange blade is pretty narrow which I feel isn't quite as desirable as something slightly broader to allow for stiffness and steeper bevels.
Was also thinking about the salyani as it's pretty sickle-like and quite lean. Unsure on if it'll outperform the mutiny in this applicaiton though.
 
Coarse vs refined edges have different advantages in different situations.
Coarse edges do better in pull cuts (sliding the blade) through fibrous materials (rope, fabric, vines). They sometimes perform better with certain steels that have large jagged carbides that can act like teeth along the edge. These are usually high alloy steels so essentially the opposite of what we use.

Refined edges do better in push cutting- chopping wood is essentially pure push cutitng. Polished edges also have a more uniform apex with less irregulaties and defects. This helps them last longer, especially in high impact wood chopping and the like.

It's possible that a coarser edge will help with these thin flexible, ropelike saplings. It will have some disadvantages for edge holding in chopping more solid woods though. Higher sharpness in general helps a lot with this kind of cutting. We tested some very thick blades in the past and found that as long as the apex was very fine and very sharp that they snipped through this kind of thing very well.
I think that the technique changes mentioned prior (particularly the holding and tensioning) will be more likely to give noticeable results than a change in edge style.
 
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