I just can't get the hang of stropping for maintenance

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KennyB

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Jan 19, 2010
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Well, I've been playing around with stropping for a long time and just haven't really "got it down" like I have with sharpening. I've found a nice addition to an edge's finish off of my hone by doing about a dozen strokes per side on the strop with light pressure and no over/under angle.

However when it comes to stropping to maintain an edge or bring an edge back I just don't think I've figured out the appropriate mix of pressure and angle. At first when I noticed an edge had dulled significantly from where I started ( though not in terms of practical, applicable cutting ability ) that if I stropped with a little bit of pressure it would bring the edge back. But I could never really get a hold on how far I could let it go, or how much pressure to use to avoid either rolling over the edge and accidentally dulling it, or just doing nothing. So I had really mixed results.

Lately I have thought that maybe I'm going about it in the wrong direction. That maybe instead of waiting for any noticable decrease in the edge's sharpness, that I should just strop a few strokes per side after a little bit of cutting. You know, after the day is done or after a moderate sized cutting task. I don't think stropping after every time I open a package of food would be appropriate, but maybe waiting a week to strop after such use is a little too long. Either way I'm not really sure what I should expect out of it, I'm kind of chasing the mythical "perpetual hair whittling edge" that I've heard people mention.

I've been wondering if maybe I'm asking too much of my strop which is just bare leather, but I don't really want to jump the gun and complicate it without really having the technique and principles down. If it's something in user error I'm going to have equally unsatisfactory results while using compound is what I figure. On the other hand, the highest grit I finish on is 1000 JIS and I prefer the 600 mesh from DMT, so i think a 1 micron or greater compound would probably do more to the metal than the leather can. From what I understand, vegetable tanned leather is pretty much devoid of any abrasives? I mean, it seems like it does something nice for "finishing" an edge, but not so much for restoring one.
 
Bare leather can only accomplish so much. Especially off of that coarse of stones. Try some 8u cbn. Will make a nice finisher off your current setup.

Your other option is adding some higher grit stones and touching up on those. I typically dont strop till after 8 , 15 or 30k stones. But you can if you use the right compound.

Fwiw my daily touchup before my edc knives go back to drawer is normally 0.1u cbn on roo. Or 0.1u poly on nanocloth..
 
http://www.bladeforums.com/forums/showthread.php/750008-Stropping-angle-plus-pressure

Disclaimer I am still trying to master the basics of sharpening, but I try to share what I have learned from experience so far:

To my understanding you don't use pressure while stropping as you can be doing more damage than good.

Not until very recently did I start experimenting with a leather belt for stropping and that is a very recent thing so I can't comment too much on that. Before that I've usually stropped my knife on cardboard, usually a cut up kleenex box gave decent results, and I get mixed results using other pieces of cardboard but eventually learned how to spot decent cardboard to strop my knife with. I mention this because the cardboard is far more abbrasive than the leather belt I am using as a strop and it brought the edge back more when I dulled it more than that belt on it's own ever will (no compound). And I have noticed that what blade steel in my knife plays a role as well. The 440a in my Rough Rider Canoe, Kershaw Cryo, and all my other stainless steel knives didn't respond to stropping as well as my carbon steel Opinel. The Opinel I have stropped on cardboard while cutting up a lot of cardboard and it probably saved me from having to sharpen 1-2 additional times (I sharpen my knives sooner than need to if given the option as I like to keep them very sharp). Where as the other blade steels I have wouldn't have responded anywhere near as well.

So it could be your technique or needing something more abrasive before going to plain leather to get the results you seek.

(Prior setup that I used the cardboard with involved 600grit eze lap diamond, and 2 unknown grit sharpening steels. Current is DMT C/F/EF stones + leather belt which is new so I haven't tried the belt or cardboard as a strop with this setup all too much.)
 
KennyB said:
Well, I've been playing around with stropping for a long time and just haven't really "got it down" like I have with sharpening. I've found a nice addition to an edge's finish off of my hone by doing about a dozen strokes per side on the strop with light pressure and no over/under angle.

However when it comes to stropping to maintain an edge or bring an edge back I just don't think I've figured out the appropriate mix of pressure and angle. At first when I noticed an edge had dulled significantly from where I started ( though not in terms of practical, applicable cutting ability ) that if I stropped with a little bit of pressure it would bring the edge back. But I could never really get a hold on how far I could let it go, or how much pressure to use to avoid either rolling over the edge and accidentally dulling it, or just doing nothing. So I had really mixed results.

Lately I have thought that maybe I'm going about it in the wrong direction. That maybe instead of waiting for any noticable decrease in the edge's sharpness, that I should just strop a few strokes per side after a little bit of cutting. You know, after the day is done or after a moderate sized cutting task. I don't think stropping after every time I open a package of food would be appropriate, but maybe waiting a week to strop after such use is a little too long. Either way I'm not really sure what I should expect out of it, I'm kind of chasing the mythical "perpetual hair whittling edge" that I've heard people mention.

I've been wondering if maybe I'm asking too much of my strop which is just bare leather, but I don't really want to jump the gun and complicate it without really having the technique and principles down. If it's something in user error I'm going to have equally unsatisfactory results while using compound is what I figure. On the other hand, the highest grit I finish on is 1000 JIS and I prefer the 600 mesh from DMT, so i think a 1 micron or greater compound would probably do more to the metal than the leather can. From what I understand, vegetable tanned leather is pretty much devoid of any abrasives? I mean, it seems like it does something nice for "finishing" an edge, but not so much for restoring one.
Click to expand...

Stropping on plain leather is only going to do so much, for maintenance you need an abrasive in the mix, and preferably on a hard surface. In your case you could claim some of the mud from your 1k and mop it up with a sheet of paper. Let it dry and use that wrapped around a dry stone - will work wonders for restoring an edge and refining it just a bit over the 1k stone finish. Then on to the plain leather for a final burnish, but in reality you could finish with a sheet or two of plain paper wrapped around the stone and get better results at that grit. A very small drop of oil worked into the paper with the dried JWS mud will "toughen" up the paper and will work just a bit better and last longer.

Martin

Edit to add video link
https://www.youtube.com/watch?v=RXr-FPME-jc

This shows how I do it, using a Washboard as a base, but works well with a dry stone too. I didn't use a drop of oil in this case. If you do use oil, do not wrap around a waterstone or some of the it might be absorbed.
 
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HeavyHanded said:
Stropping on plain leather is only going to do so much, for maintenance you need an abrasive in the mix, and preferably on a hard surface. In your case you could claim some of the mud from your 1k and mop it up with a sheet of paper. Let it dry and use that wrapped around a dry stone - will work wonders for restoring an edge and refining it just a bit over the 1k stone finish. Then on to the plain leather for a final burnish, but in reality you could finish with a sheet or two of plain paper wrapped around the stone and get better results at that grit. A very small drop of oil worked into the paper with the dried JWS mud will "toughen" up the paper and will work just a bit better and last longer.

Martin

Edit to add video link
https://www.youtube.com/watch?v=RXr-FPME-jc

This shows how I do it, using a Washboard as a base, but works well with a dry stone too. I didn't use a drop of oil in this case. If you do use oil, do not wrap around a waterstone or some of the it might be absorbed.
Click to expand...

Nice tip! I have some MDF that I loaded up with CrO, maybe I could just load it with the waterstone mud instead? I like the paper idea, just don't have any tape and would like to try it right away lol Plus just having a dedicated piece of MDF to put the slurry on sounds more convenient.
 
KennyB said:
Nice tip! I have some MDF that I loaded up with CrO, maybe I could just load it with the waterstone mud instead? I like the paper idea, just don't have any tape and would like to try it right away lol Plus just having a dedicated piece of MDF to put the slurry on sounds more convenient.
Click to expand...

Give it a try!
You don't need tape or anything either, just wrap that paper around another stone and you have a surface that's even harder than the MDF. Also you don't have to worry about the water messing with the MDF (swelling, small buckles, etc). Lightly picking it up with a sheet of paper is the easiest, and a hair drier or careful use of a stove top can dry it out asap. I believe you use Norton waterstones - have used this method with that grit and it worked very well. You have all the usual strop suspects, use light pressure and mind the angle control, but is way more forgiving than using leather, and disposable once it loads up or tears. Have also used this with newspaper, but is a bit trickier to pick up the grit due to the paper being more fragile. Once dried and wrapped around a dry stone, is a very firm surface for maintenance stropping. I prefer copy or writing paper, especially for a final polish. Coming off the stone grit, a handful of passes on a plain sheet of paper will jump it up another little bit - not much good for maintenance but good for a final swipe.

The MDF will work fine as well I'm sure, have never tried it though.
 
HeavyHanded said:
Give it a try!
You don't need tape or anything either, just wrap that paper around another stone and you have a surface that's even harder than the MDF. Also you don't have to worry about the water messing with the MDF (swelling, small buckles, etc). Lightly picking it up with a sheet of paper is the easiest, and a hair drier or careful use of a stove top can dry it out asap. I believe you use Norton waterstones - have used this method with that grit and it worked very well. You have all the usual strop suspects, use light pressure and mind the angle control, but is way more forgiving than using leather, and disposable once it loads up or tears. Have also used this with newspaper, but is a bit trickier to pick up the grit due to the paper being more fragile. Once dried and wrapped around a dry stone, is a very firm surface for maintenance stropping. I prefer copy or writing paper, especially for a final polish. Coming off the stone grit, a handful of passes on a plain sheet of paper will jump it up another little bit - not much good for maintenance but good for a final swipe.

The MDF will work fine as well I'm sure, have never tried it though.
Click to expand...

Eh, paper sounds simple enough just wrapping it around, i didn't think of it being wet and kind of figured it would be too stiff to go flat over the stone. Lined notebook paper work fine too?

Only thing is I sometimes have difficulty working up a slurry with my Norton hone. I could use the flattening stone but then I would get grit contamination wouldn't I?
 
KennyB said:
Eh, paper sounds simple enough just wrapping it around, i didn't think of it being wet and kind of figured it would be too stiff to go flat over the stone. Lined notebook paper work fine too?

Only thing is I sometimes have difficulty working up a slurry with my Norton hone. I could use the flattening stone but then I would get grit contamination wouldn't I?
Click to expand...

Even with the paper being a bit wrinkled you can still fold it plenty tight over the stone, especially if folded with the grain. Can be used wet as well but will be a bit swollen with water, so more deflection possible, the surface can disintegrate under pressure/abrasion, and the abrasive will move around more and be less aggressive on the steel. Not convenient for storage either. A small drop of oil worked across the sheet (after collecting mud and allowing to dry) and allowed to soak in will toughen up the paper and seems to help the abrasive "stick" into the paper a bit better. Oil will swell the paper far less than water, and helps it lay flat.

I highly recommend cutting a slice off the stone - a hacksaw blade or two can get a piece off if you'd rather not spend $ on a carbide or diamond sawsall blade. Otherwise, a diamond plate can whip up slurry, or collect the mud from a sharpening if nothing else. Have used an old knife if no sharpening was needed, and with my SiC oilstones I keep a small piece of hacksaw blade (with paint removed) right with the stone. You can actually use it to scrub the high spots on the stone with the broken end (like sharpening a chisel), and help keep it flat while collecting your maintenance grit.

Flattening stone will definitely throw large grit into the works, I wouldn't go that route.
 
I took a nice square meat cleaver I had, and just worked up a slurry with that. Tried the paper, but it folded/warped too much before I read the bit about folding it with the grain.

However, I applied the slurry once it was semi-dry onto the top of my MDF strop, righ over the CrO. It provided a noticible tactile sensation and I could even hear it, so I know there's definitely some abrasive action going on there but I can't so conclusively say it's really made a huge difference so far since I've only been using it on one knife that I've been kind of messing with the profile on. That's kind of a different story, but from that I've noticed that it doesn't really seem to take burrs or any kind of deformations off. Should it?

I wonder how often I would need to reapply more onto the top of the CrO--or if perhaps I should just strip that and apply it to the MDF. I think the CrO forms kind of a "sealed' and "softer" layer for the wet slurry to adhere to without swelling the surface or just flaking off though. I do like the idea of repurposing all that slurry for strop compound though, and if anything else I do like the finish off of this more than just off my DMT F hone.
 
KennyB said:
I took a nice square meat cleaver I had, and just worked up a slurry with that. Tried the paper, but it folded/warped too much before I read the bit about folding it with the grain.

However, I applied the slurry once it was semi-dry onto the top of my MDF strop, righ over the CrO. It provided a noticible tactile sensation and I could even hear it, so I know there's definitely some abrasive action going on there but I can't so conclusively say it's really made a huge difference so far since I've only been using it on one knife that I've been kind of messing with the profile on. That's kind of a different story, but from that I've noticed that it doesn't really seem to take burrs or any kind of deformations off. Should it?

I wonder how often I would need to reapply more onto the top of the CrO--or if perhaps I should just strip that and apply it to the MDF. I think the CrO forms kind of a "sealed' and "softer" layer for the wet slurry to adhere to without swelling the surface or just flaking off though. I do like the idea of repurposing all that slurry for strop compound though, and if anything else I do like the finish off of this more than just off my DMT F hone.
Click to expand...

The binders in the CrO are going to prevent the grit from embedding in the MDF very well, much like a wax might. Good possibility most of the grit is just sliding around on the surface. Don't worry so much about warping of the paper, as long as its folded reasonably tight there won't be any issues. There should be a big change in the character of the edge, no mistaking that something is happening - on white paper you should be able to see the black of the steel coming off from the first or second pass. Will take a burr off very quickly, and with a bit of pressure could raise one as well, especially with 1k grit. I know they can be a bit painful to sit through, but the video I linked to in the first response shows the entire operation, simple tho it is, might give you some ideas. Is only about 10 minutes.

Martin
 
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