New Knife Edge

[cziv]

I just bought a new XM-24. I want to use the factory bevel as long as possible before I send it to Rick for re-sharpening or re-sharpen it myself.

It arrived with the edg catching on copy paper and wouldn't make a clean slice without immediately catching or staring to cut for an inch or two and then tearing.

I stropped it on balsa with 6, 3. and 1 micron dia-paste. about 8 light passes on each strop for 24 per side.

Took a copy paper and sliced it clean through - didn't hardly make a sound. Sliced what was left in my hand it was like I never did all that stropping (see above).

I wiped it on my shorts a couple of times in a stropping motion and zippp right through again!

Can cutting something leave a residue on a blade? This was some paper that's sitting out for a couple of weeks and felt like the top piece (One I cut) had a bit of dust on it. What do ya think?

 

[Esav Benyamin]

Paper shouldn't leave that much of a residue, although heavy brown stock might. The original stropping should have taken care of any burr. But the fact that it took another stropping after such minimal slicing would indicate you do have a burr there still.

How obtuse is the secondary bevel? Perhaps your stropping was polishing the shoulders more than removing a burr.

 

[cziv]

Paper shouldn't leave that much of a residue, although heavy brown stock might. The original stropping should have taken care of any burr. But the fact that it took another stropping after such minimal slicing would indicate you do have a burr there still.

How obtuse is the secondary bevel? Perhaps your stropping was polishing the shoulders more than removing a burr.

It's hard to tell. These blades are very thick. Usually I can lay a blade on it's side and expose some epty space, roll it up to the perfect cngle and strop. This thick edge makkes it difficult, even with a flashlight bhind it to see anything under th blade and roll it upward onto the finished edge.

Try again tomorrow I guess - thanks.

 

[HeavyHanded]

When in doubt, you and a Sharpie can figure it out. Seriously, they're not just for grinding - make a few dots along the bevel every 1/4 - 1/3 of an inch and you'll see if the strop is hitting the bevel right after a half dozen passes. The Sharpie dots will start to fade and disappear. One other thing, if the copy paper has been sitting out in humid conditions that can make a big difference - the moisture content of the paper might not be even or more likely the first cut was a fluke and you have a burr.

HH

 

[Obsessed with Edges]

I'm betting it's a wire edge that rolled to one side when cutting the paper, then straightened out again when stropping on your pants (indicating it's a very thin wire). I usually get rid of most of these by lightly slicing into the corner of a piece of hardwood two or three times, OR making several cuts through some light cardboard (toilet paper roll, paper towel roll, Kleenex box, back of a notepad, etc.), which should catch & break most of it off, then strop again and re-test your edge.

 

[cziv]

I'm betting it's a wire edge that rolled to one side when cutting the paper, then straightened out again when stropping on your pants (indicating it's a very thin wire). I usually get rid of most of these by lightly slicing into the corner of a piece of hardwood two or three times, OR making several cuts through some light cardboard (toilet paper roll, paper towel roll, Kleenex box, back of a notepad, etc.), which should catch & break most of it off, then strop again and re-test your edge.

Not sure really but had another stopping session and this big bad blade is now hair shaving sharp - and will repeat w/o any touching up. the blade & bevel angle is very thick. Thanks!

 

[clayallison]

I just bought a new XM-24. I want to use the factory bevel as long as possible before I send it to Rick for re-sharpening or re-sharpen it myself.

It arrived with the edg catching on copy paper and wouldn't make a clean slice without immediately catching or staring to cut for an inch or two and then tearing.

I stropped it on balsa with 6, 3. and 1 micron dia-paste. about 8 light passes on each strop for 24 per side.

Took a copy paper and sliced it clean through - didn't hardly make a sound. Sliced what was left in my hand it was like I never did all that stropping (see above).

I wiped it on my shorts a couple of times in a stropping motion and zippp right through again!

Can cutting something leave a residue on a blade? This was some paper that's sitting out for a couple of weeks and felt like the top piece (One I cut) had a bit of dust on it. What do ya think?

Depending on where you live, dust can be a pretty big factor. I was really shocked to see under the microscope how much my .125 micron strops were scratching the blade after sitting out in the open air for a while. I live in NM and it's pretty dusty here. I talked to the scientist at Sandia Labs that we're working with and his estimation was that the dust here is more than enough to contaminate the surfaces of the strops. I imagine the copy paper is porous enough that it would really hold the dust.

I'm sure Obsessed is right too about the wire edge.

 

[Obsessed with Edges]

Depending on where you live, dust can be a pretty big factor. I was really shocked to see under the microscope how much my .125 micron strops were scratching the blade after sitting out in the open air for a while. I live in NM and it's pretty dusty here. I talked to the scientist at Sandia Labs that we're working with and his estimation was that the dust here is more than enough to contaminate the surfaces of the strops. I imagine the copy paper is porous enough that it would really hold the dust.

I'm sure Obsessed is right too about the wire edge.

No shortage of dust here, either. I'm about 15 miles north of Albuquerque. When the printer paper was mentioned, as a possible source of contamination, the 'dust factor' crossed my mind too. My printer sits next to the window, which is cracked open most of the time. Always at least a little dust on the paper. The dust is simply a fact of life here in the great, desert southwest (I grew up here). And with all the fires we've had this season, I've added airborne ash to the list of possible contaminants, too. We did see ash settling on our property, even from the huge fire in eastern Arizona (200 miles away). At least in the last few days, we've had a little tease of rain, so the dust has (temporarily) settled a bit.

P.S., I have sort of resigned myself to at least a few larger scratches off the strops, for the above-mentioned reason.

 

[cziv]

Hard to believe you guys can see a scratch caused by a grain of dust on you blade?

 

[Esav Benyamin]

The grains of dust in the great, desert southwest are sand, which is notorious for dulling blades. Like sandpaper.

 

[cziv]

The grains of dust in the great, desert southwest are sand, which is notorious for dulling blades. Like sandpaper.

Dulling I can understand but I've never heard of stropping and getting a scratched up blade from the dust on a strop. I keep mine wrapped in Saran Wrap cuz I've heard of this but I can't imagine being able to even see a dust sized scratch on the shoulder or side of a satin finish for e.g.

 

[Heiheit]

Sounds to me like you either over stropped or under stropped.

 

[unit]

I've never heard of stropping and getting a scratched up blade from the dust on a strop.

The higher the degree of luster, the easier a tiny imperfection is to spot.


This is a reason some people do NOT like mirror polished blades or edges. These imperfections that can be caused by DUST are easily spotted and potentially obsessed over. If you fear using a knife for this reason, you have transformed a nice functional tool into a piece of jewelry (not necessarily a bad thing depending on what you want/need).

Not trying to convince anyone of anything here, just sharing rationale for why *I* like my user edges polished not quite to a mirror edge.

Most dust around here is not capable of scratching most blade steels, but the dust down in my garage will CERTAINLY mar up even really hard blades...and there are many ways that particles can be carried around. It only requires a particle with significant hardness that is larger than your final abrasive.

Edit to add. Every time you sharpen, you generate particles capable of contaminating your strops Mirror polished deserve respect!

 

[Obsessed with Edges]

The grains of dust in the great, desert southwest are sand, which is notorious for dulling blades. Like sandpaper.

It's true. I think most of it is from sandstone, around here. Every time I've taken a walk outside, I've considered trying the fine sand on the ground as a stropping compound (coarse, relatively). It's silica, if I'm not mistaken. The only downside is, silica's not quite as hard as other abrasives, and some abrasion-resistant steels might not be fazed by it.

 

[unit]

It's true. I think most of it is from sandstone, around here. Every time I've taken a walk outside, I've considered trying the fine sand on the ground as a stropping compound (coarse, relatively). It's silica, if I'm not mistaken. The only downside is, silica's not quite as hard as other abrasives, and some abrasion-resistant steels might not be fazed by it.

It works pretty well on some knives (only tried it on carbon steel traditionals), but I agree it would have limited effectiveness with some really hard steels...but I would speculate that if you HAD to do it, you could get some results with quartz sand (pretty common component of sand), but it might take some time

 

[Obsessed with Edges]

It works pretty well on some knives (only tried it on carbon steel traditionals), but I agree it would have limited effectiveness with some really hard steels...but I would speculate that if you HAD to do it, you could get some results with quartz sand (pretty common component of sand), but it might take some time

I had smeared a bit of it on a piece of 1x2 a while back, and swiped the edge of one of my knives across it, just to see if it'd do much. Sort of 'inconclusive' results then. I've thought about soaking a piece of leather in it, with water, to let some of the finer stuff settle into the leather, then re-try it as a strop. Might have to re-visit that. Not expecting much, but my curiosity keeps goading me to try it. I know some of the 'survival' afficionados have flattened chunks of sandstone for sharpening, but again, don't know how effective it actually is.

 

[Obsessed with Edges]

Dulling I can understand but I've never heard of stropping and getting a scratched up blade from the dust on a strop. I keep mine wrapped in Saran Wrap cuz I've heard of this but I can't imagine being able to even see a dust sized scratch on the shoulder or side of a satin finish for e.g.

On a satin finish, I agree, it wouldn't be as noticeable. Lately, I've been spending a lot of time sharpening & polishing the blades on two Opinels (one carbon, the other is 12C27M stainless). Their blades are a very slight convex, and I've taken the microbevel off the factory edge. This lends itself perfectly to laying the blade flush on a strop (or sandpaper) when sharpening, and also polishes the lower half or so of the blade at the same time. As the blade's side becomes more polished, there's a LOT more shiny surface area upon which ANY scratch will really stand out. Especially under bright light or sunlight. Great way to really find out how dirty the strops are.

 

[Magnaminous_G]

I'm betting it's a wire edge that rolled to one side when cutting the paper, then straightened out again when stropping on your pants (indicating it's a very thin wire). I usually get rid of most of these by lightly slicing into the corner of a piece of hardwood two or three times, OR making several cuts through some light cardboard (toilet paper roll, paper towel roll, Kleenex box, back of a notepad, etc.), which should catch & break most of it off, then strop again and re-test your edge.

+1

Very useful post, thanks! I was wondering what was going on with some of my knives that seemed to strop up well enough, but after just a little cutting, they were mysteriously dull again. I think this was it; the micro wire thing. I made sure to completely sharpen the burrs off and then check the edge well. Sure enough, cutting solid now and consistently.

You should post useful tips more often.