Stropping on guided systems?

[Ilikesharpstuff]

I know this can be a controversial topic and stropping is all but beaten to death, but I have some questions for those of you who have or do strop on guided sharpening systems. I understand the theory of stropping, but whether done freehand or on my TsProf Blitz 360 I can never discern a true improvement in sharpness/keenness.

For anyone who is a regular user of strops on a guided system, how do you set your angle? The same as you sharpened at? 1 degree less? .05 degrees less? Is there an optimal differential to shoot for? I have both Jende nanocloth loaded with .5 micron diamond emulsion, and a cowhide strop with no compound. I typically try to strop with as little pressure as possible...not even the weight of the arm/strop, and I usually try to match the angle that I sharpened at exactly. Whether I do 5 strokes per side or 50 with either or both strops, I can't tell much difference in sharpness from straight off my Venev F1500. That said I don't think I'm dulling/rounding the edge, but I don't feel that I'm refining it either. Does that just mean I do a really good job deburring? Would I benefit from setting a lower angle and applying more pressure? Any other thoughts or pointers?

Thanks!

 

[jjg6319]

Wouldn't you go at a slightly higher angle to get to the apex? I think you only need a couple strokes also. This topic has been asked recently and you might do a search.

Similar topic but might be useful to you:

Stropping vs. Sharpening

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[Ilikesharpstuff]

Wouldn't you go at a slightly higher angle to get to the apex? I think you only need a couple strokes also. This topic has been asked recently and you might do a search.

Similar topic but might be useful to you:

Stropping vs. Sharpening

Hey everyone, Fairly new member here and I’d like to get more embedded in the community. SCROLL TO BOLD PORTION BELOW TO SKIP SMALL TALK. I find myself either having a couple knives and a rise in my savings account - or the opposite; a ton of knives and not as much savings lol. I often joke...

www.bladeforums.com

Typically you'd strop at a slightly lower angle than sharpening because the strop material will compress to some degree and "wrap around" the bevel to hit the apex. There's a great example of this effect here. The less pressure you use the closer you should be able to match the angle you sharpened at, but both of my strops are fairly soft and I think there would be some degree of compression no matter how little pressure I think I'm applying. More pressure creates more of a convex effect and theoretically allows you to lower the stropping angle even further and still hit the apex. This would not be true with wood or other solid strop materials.

Thanks for the link but sadly my question doesn't get answered there. Still hoping someone can chime in and tell me they get the best results when stropping at half a degree less than they sharpened at, etc. If not I'll just have to keep experimenting and see if I can find the magic setup for my TSProf.

 

[SCTorrero]

I have had good results with the lapping film on my KME, same angle as the sharpening. Light strokes from 9um, to 6, to 3, to 1, then .5um on leather. I go really light on the leather because that substrate is a little softer than the glass lapping blanks and I don't want to undo my work.

 

[Twindog]

On the WickedEdge, I use the same angle, but very light pressure to avoid rounding the edge.

 

[WhitleyStu]

I power strop on a Reeder 2x72 and strop at 1.5°-2° less than sharpening angel. On a 20° per side grind I strop at 18°-18.5° which produces a razor edge and satin finish using pink rouge. For a more shiny edge finish I go with green rouge. A very light touch and low belt speed produces the best edge.

 

[chalby]

How is your edge before stropping? Is it easily shaving sharp and uniform along the whole edge?

If so, then you probably are doing a very good job at deburring without the strop. At that point, if you are using the strop effectively(with 0.5 micron) you will end up with a less toothy and a better push-cutting edge. It will depend on your own use whether you feel that is a good thing or whether it's not worth the time or you may prefer a toothy edge for what you are doing. Of course, if you are only spending a small amount of time stropping then you won't change the characteristics of the edge too much.

If you are really not noticing any difference, then you may not be using quite enough pressure or you are not getting the apex. Having said that F1500 is quite a fine finishing grit as well(about 6000 JIS) and finer grits are generally better for deburring.

 

[Blade Lab]

Most say you should strop at the sharpening angle. I roughly go by the research conducted by Vadim Kraichuk (RIP), who did many tests and determined that different steels benefit from different honing angles. As a general rule, the less wear-resistant a steel is, the better it does with a higher honing angle. Very wear-resistant steels do better at or very slightly below the sharpening angle (like -0.1°). But in all cases, final passes should be at the sharpening angle.

For example, for something soft like a Wusthoff chef's knife, I'll strop at around +2° and then finish at the edge angle. For M390 and above I just strop at the sharpening angle.

Full disclosure: Vadim generally honed on paper or felt wheels, and I hone on the Ken Onion blade grinder with leather belts and various compounds. I'll often finish up with a couple passes on a leather strop with .5 micron diamonds.

 

[Obsessed with Edges]

I know this can be a controversial topic and stropping is all but beaten to death, but I have some questions for those of you who have or do strop on guided sharpening systems. I understand the theory of stropping, but whether done freehand or on my TsProf Blitz 360 I can never discern a true improvement in sharpness/keenness.

For anyone who is a regular user of strops on a guided system, how do you set your angle? The same as you sharpened at? 1 degree less? .05 degrees less? Is there an optimal differential to shoot for? I have both Jende nanocloth loaded with .5 micron diamond emulsion, and a cowhide strop with no compound. I typically try to strop with as little pressure as possible...not even the weight of the arm/strop, and I usually try to match the angle that I sharpened at exactly. Whether I do 5 strokes per side or 50 with either or both strops, I can't tell much difference in sharpness from straight off my Venev F1500. That said I don't think I'm dulling/rounding the edge, but I don't feel that I'm refining it either. Does that just mean I do a really good job deburring? Would I benefit from setting a lower angle and applying more pressure? Any other thoughts or pointers?

Thanks!

More often than not, if you don't notice any change at all in sharpness when stropping, no matter how many strokes are used, it usually means the edge wasn't thin enough or refined enough to respond to stropping. That means a little more needs to be done with the stones before going to the strop. Verifying the presence of a burr along the full length of the cutting edge is the best indicator the edge is ready for stropping. And better still, if it's seen that the burr is very, very thin & fragile itself, then an immediate, noticeable change in sharpness should be seen when you begin stropping - like in the first 1-3 passes on the strop. If the burr is heavier & tougher, it may take a little longer to see some change. But you should notice an improvement in something much less than 50 passes, at the very least. In that circumstance, it's still better to go back to the finishing stone to thin it a little more, before attempting stropping.

Also need to verify that the strop is in fact making contact right up to the apex of the edge. If the stropping angle is too low, you'd also likely see rounding or polishing of the shoulders of the edge bevels behind the apex, but not see any effect at the apex.

 

[Ilikesharpstuff]

Thanks for all the replies everyone!

How is your edge before stropping? Is it easily shaving sharp and uniform along the whole edge?

If so, then you probably are doing a very good job at deburring without the strop. At that point, if you are using the strop effectively(with 0.5 micron) you will end up with a less toothy and a better push-cutting edge. It will depend on your own use whether you feel that is a good thing or whether it's not worth the time or you may prefer a toothy edge for what you are doing. Of course, if you are only spending a small amount of time stropping then you won't change the characteristics of the edge too much.

If you are really not noticing any difference, then you may not be using quite enough pressure or you are not getting the apex. Having said that F1500 is quite a fine finishing grit as well(about 6000 JIS) and finer grits are generally better for deburring.

Yes, before I ever go to the strop I verify that the edge is uniform and sharp. Since it is hard to shave without breaking the setup in the TSProf I usually test the sharpness by pushing a piece of thermal receipt paper into the edge. Probably 95% of my usage is cutting various types of tape to open packaging and boxes, the rest being cardboard and fine rope/twine so typically I'm happy with good push cutting performance. I do understand the F1500 is extremely fine and the level of refinement beyond that could easily be considered the realm of diminishing returns. It is not lost on me that I could simply be expecting more from stropping than what is realistically attainable.

More often than not, if you don't notice any change at all in sharpness when stropping, no matter how many strokes are used, it usually means the edge wasn't thin enough or refined enough to respond to stropping. That means a little more needs to be done with the stones before going to the strop. Verifying the presence of a burr along the full length of the cutting edge is the best indicator the edge is ready for stropping. And better still, if it's seen that the burr is very, very thin & fragile itself, then an immediate, noticeable change in sharpness should be seen when you begin stropping - like in the first 1-3 passes on the strop. If the burr is heavier & tougher, it may take a little longer to see some change. But you should notice an improvement in something much less than 50 passes, at the very least. In that circumstance, it's still better to go back to the finishing stone to thin it a little more, before attempting stropping.

Also need to verify that the strop is in fact making contact right up to the apex of the edge. If the stropping angle is too low, you'd also likely see rounding or polishing of the shoulders of the edge bevels behind the apex, but not see any effect at the apex.

I wouldn't say I don't notice any change at all, maybe more that I'm not blown away by what a difference stropping seems to make as many people seem to be. It could simply be an issue of my expectations versus reality. I sharpen at 15-18 degrees per side on my EDC knives which currently consist of Magnacut, CruWear, M390, or CPM-154. I try to remove the burr before going up in grit with each stone and I'm starting to think I just do so quite successfully. I see so many people talk about what a huge difference stropping makes, but I guess that may be limited to situations where there is a significant burr remaining after the stones. Perhaps I need to think of stropping more as peace of mind that the burr is absolutely gone versus something that will make my already shaving edge much sharper.