Pocket sharpener question

[NixKustoms]

So I was wondering what the consensus is on pocket sharpeners.

I heard from a guy that these things are generally bad to use.

So what is your opinion about them? Do they wreck the knife?

I was thinking about getting one for touch up in the bush, but if they aren't that great I think I'll just find a flat stone in a river to use.

 

[stealthchaser13]

you would be better off with something more like a "GI keychain sharpener" than one of those pull-throughs.

here is what i am referring to:

 

[singularity35]

I don't think those are too bad. Those look something like croc sticks to me. I think it's the carbide ones that scrape material from your knife that kills an edge. I wouldn't use that though. If I absolutely needed to carry a sharpener, I'd go with diafolds.

But let's wait for the more knowledgeable guys, I may be wrong.

 

[mdc5162]

I have used two different ones, a gerber branded one and i forget the other. I am pretty sure they made the knife duller and I would say a far cry from a "working edge."

 

[J D Wijbenga]

Never used one o those. If they are with ceramics I would expect you to be able to use them with some effect. Depending on the edge angle of your knife.

I prefer the Spyderco Double stuff and Fallkniven DC4 for sharpening on the road. Both are good quality sharpeners.

JD

 

[stitchawl]

These won't hurt your knife, but they may not help it either. It all depends upon the edge angle. If it's the same as these croc sticks, they will touch up the edge. If the angle is different, the sticks may not contact the edge and actually do nothing for you. I'd suggest you try them and see if your edge improves. If not, no harm. If so, you've got a handy pocket sharpener to use.

Stitchawl

 

[Noctis3880]

So I was wondering what the consensus is on pocket sharpeners.

I heard from a guy that these things are generally bad to use.

So what is your opinion about them? Do they wreck the knife?

I was thinking about getting one for touch up in the bush, but if they aren't that great I think I'll just find a flat stone in a river to use.

I've heard left and right in here that those are bad for edges, but nobody really went over why. They really DO seem to work for the most part, and I've seen little to no ill effects of using one. Though my coworker did chip his edge once using it, he said it was because he twisted it, plus his knife was a cheap Victorinox paring knife.

Since I mirror polish all my edges and never really use my knives all that hard, I have little need for such touchups. Though I did use my DMT Diafolds to pretty good effect on my coworker's knives. The card versions seem like a good choice if you want to do it with a bit of stropping style.

 

[mrdavidross321]

i use this thing for my SAKs but thicker knives like Becker Necker it dont do much, the little rod works good for serrations, but SAKs are the only knives i got with serrations so i dunno. when i slide the Becker Necker or any thicker than a SAK or slipjoint it scrapes the sides or walls of the edge not really all the edge so it dont really sharpen at the bottom of the V (if that makes sence)

 

[M0NK]

get one or two of those DMT folders. if you know what you're doing, you don't have to worry about matching angles of blade vs "device".

i've also seen some guys make small strop blocks with the coarse (BRK black) strop paste and keep it in a small zip lock bag. looks viable to me.

 

[aephilli]

Would it be a valid test to use a sharpie on the blade edge to test the contact point of the device to the blade?

 

[Obsessed with Edges]

So I was wondering what the consensus is on pocket sharpeners.

I heard from a guy that these things are generally bad to use.

So what is your opinion about them? Do they wreck the knife?

I was thinking about getting one for touch up in the bush, but if they aren't that great I think I'll just find a flat stone in a river to use.

This particular one (pictured), with the ceramic inserts, won't necessarily be too bad for your blade (as in, it's not likely to damage it). I actually had one like this, but found it relatively ineffective. Results will vary widely, depending upon whether your knife's edge bevel matches the pre-set angle of the sharpener.

The REALLY lousy ones are done the same way, but with the carbide inserts. Those things will chew up an edge quick (not in a good way). Most of the trouble with those lies in the direction of edge travel, through the sharpener. Imagine trying to 'trim' the edge of a piece of paper with a pair of scissors, except that you're holding the scissors vertically, with the jaws apart, and you're pulling the paper, edgewise, through the 'V' of the scissors. The paper will likely slide, get pinched, get cut, slide, get pinched, get cut, etc., all the way through. Imagine what the edge of the paper looks like, after you've pulled it through the scissors. That's more or less what happens to a knife edge, after passing through one of the 'V' style carbide sharpeners. Leaves lots of wicked, rough-looking 'sawteeth' of weak, shredded steel in it's wake. They might 'seem' to cut aggressively for a very short bit, but then they'll break off or fold over. Might even leave some cracks/chips in the edge too.

 

[dsmegst]

In a desperate situation where you have a completely dull knife, it can help you. If you have any sort of an usable edge, a pull through sharpener will damage the edge further.

I've tested a few of these and observed the scratch patterns under a microscope. They were bad. Tiny slivers of metal hanging off everywhere and large dips and valleys left over from the torn metal all along the edge. Not a pretty sight.

 

[Noctis3880]

In a desperate situation where you have a completely dull knife, it can help you. If you have any sort of an usable edge, a pull through sharpener will damage the edge further.

I've tested a few of these and observed the scratch patterns under a microscope. They were bad. Tiny slivers of metal hanging off everywhere and large dips and valleys left over from the torn metal all along the edge. Not a pretty sight.

So in sort, it's essentially the direction of sharpening that makes these pull through sharpeners so bad?

 

[aephilli]

Maybe if used like "crock sticks" and don't put the edge all the way down into the crossed stix? Looks like a handy way to keep something for "touch ups" safe in a pocket. I also REALLY like the GI sharpener above, where can I get one of those?

 

[Gadgetaholic]

I've got one of those, been using it for years - it works well on a SAK or LM Wave blade. They won't harm your knives at all (unlike the carbide blade scrapers) - but I did find that it wont work on many bigger knives. I've actually stopped using mine because I get better results with a paddle strop (piece of wood, piece of leather belt that broke & green compound).

The sharpener pictured is good for someone that has no idea of how to sharpen and wants to keep their SAK blade sharp - that was me until a year ago. But they are a bit annoying to use because the ceramic rods blacken up on each swipe of the blade and you spend more time cleaning them then sharpening the blade with them.

I'd recommend a DMT Diafold as a better pocket sharpener - I'd go with course/fine personally.

What I use is not a pocket sharpener, but a portable sharpener that I can take camping with me: http://www.knivesshipfree.com/Complete-Sharpening-Kit-for-Field-or-Home-w-Clear-OtterBox
This is a better option for convex edges and provides 5 grits of sandpaper & 2 sides of a leather strop - I use green and bare (not using the black compound at all). I can use this to sharpen my SAK and my machete and others in between.

This very much looks like an infamous blade scrapper that will wreck the edges of any blade:

I would avoid the V near the middle with 'carbide' written by it.

 

[Obsessed with Edges]

In a desperate situation where you have a completely dull knife, it can help you. If you have any sort of an usable edge, a pull through sharpener will damage the edge further.

I've tested a few of these and observed the scratch patterns under a microscope. They were bad. Tiny slivers of metal hanging off everywhere and large dips and valleys left over from the torn metal all along the edge. Not a pretty sight.

That sums it up.

Here's a pic:

Here's where I got the pic (very interesting reading):
http://sharpeningtechniques.blogspot.com/2009/12/micro-photos-of-identical-knives-after.html

 

[dsmegst]

So in sort, it's essentially the direction of sharpening that makes these pull through sharpeners so bad?

I think it's a large part of it.

I divide sharpening into 3 steps, shaping/profiling the edge, refining the scratch patterns, and polishing.

A typical pull-through sharpener uses sharp carbide blades that creates a rough V shape so this pretty much destroys all the refining work you put into the blade. At best you're creating a rough micro bevel.

Then you're left with some small ceramic sticks to try and refine what's left from the carbide blades. If the ceramic is too rough, there's no way to refine the scratchs enough for a good edge. If the ceramic is too fine, there's no way to remove enough metal to fix the flat spots and valleys left from the carbide blades.

The direction of the scratches are wrong since it promotes tearing vs "feathering" and the grit steps are too wide apart with no way to refine beyond a "medium" grit level. Stropping at this point is pointless since you don't have a good enough edge.

 

[Eat Carbs]

Great responses guys.
I am looking for some type of pocket sized sharpener that I could take out camping with me to touch-up my blade at the end of the day. I plan on getting the Rat 3 and Esee Junglas blades, which are 1095 steel and I'd like to keep them in good shape. I plan on getting some good sharpening stones for home use a little down the road.

I had something like this in mind: http://www.fast-autos.net/diecast-c...-sharpening-stone-extra-fine_250358203024.jpg

 

[manowar669]

I have one of those diamond rods that I got free with a SAK purchase. It collapses down into ballpoint pen sized package. I would take it with me if I knew I needed a durable, portable field sharpener (desert island?). Sharpmaker is my usual sharpener, but you can break the rods.

 

[Obsessed with Edges]

get one or two of those DMT folders. if you know what you're doing, you don't have to worry about matching angles of blade vs "device".

i've also seen some guys make small strop blocks with the coarse (BRK black) strop paste and keep it in a small zip lock bag. looks viable to me.

Some wet/dry sandpaper and a block of wood (or any similar, flat object) to wrap it around, would also work fine. Could even take multiple grits of your choosing, the paper's thin & light for easy packing.