Stropping angles

Daniel Moore

Daniel Moore

Joined
Jul 28, 2003
Messages
2,790
I attached a couple of strips of leather belt to a wooden plank and put some hard metal buffing compound on one and left the other dry. On leather, should I strop the knife with the belly and spine flat on the surface, with the knife at a consistent angle (e.g. 20 degrees), or do it by starting out almost flat and then raising the knife as I draw until I hear the edge catch the strop? I've been doing it with the raising method, but is that necessary where the leather contours to the edge more?
 
I had trouble with edge rounding using leather. Hard smooth cardboard coated with boron carbide is much more forgiving and less likely to round the edge.
 
or do it by starting out almost flat and then raising the knife as I draw until I hear the edge catch the strop
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A while back I made a comment about stropping , that I had never had the need to do it and that part was true , well a couple of weeks ago I tried it out of boredom and my word... razor sharp went to scalpel sharp , it does make a difference.

I do it like you said in the above quote and it works fine. I use a red polishing compound , not sure of the grit but it is pretty fine.


redhawk44p
I had trouble with edge rounding using leather. Hard smooth cardboard coated with boron carbide is much more forgiving and less likely to round the edge.
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I think maybe you were doing it too hard , I strop real gentle and easy , you just want to get that burr off making sure to try to keep the edge at a consistant angle.
 
I'm just your average knife user so take that into consideration. I've tried it both ways and I just don't see where it really matters. I've come to my own conclusion that on softer steels (440a, AUS-6, etc..) I will leave the blade flatter on the leather. On more wear resistant steels (S30V, 154CM, etc..) I raise the blade up and "knock off" the burr faster.

Lower is slower, higher is faster. I don't think it really matters. (meaning just doing it is better than not)
 
Since getting some great advice here on BFC some months ago I think I've come to appreciate some of the complexities of stropping. Not only is softness or "give" of the leather or other strop material and any backing a factor but the nap of it is as well. Then you've got the pressure used when stropping, and how the geometry of the blade and edge are going to affect how that pressure is distributed and how the strop is going to squish/curve/give as a result. This really hit home when I became interested in Scandinavian ground blades .... with their very wide primary bevels they're very easy to strop because they're easy to control, plus the pressure is distributed across a much larger area than with other edge grinds.

Though I've never used an EdgePro I think I see how such good results are attained with the tape, which seems similar to stropping - the system gives much better control than you can get freehand, there's very little give to the tape and it has little or no nap. So basically the EdgePro lets you to follow a bevel very accurately, even a narrow one, hence sharpening and not dulling.

But I've also come to realize lately that with sufficient skill you can achieve sharpness that's as good or greater than with freehand stropping using a fine ceramic Sharpmaker or CrockSticks, the trick is to use very minimal pressure and patiently bring the edge to a high level of sharpness. After a lot of work and practice lately I can get nearly any decent blade push cutting newsprint 3" or more from point of hold just using ceramic, a couple even rivaling Ben Dale-level sharpness. And this edge is consistent along its entire length, much better than what I can do with stropping on leather. IMO this is mostly due to consistency, which is much harder to achieve stropping freehand with knives that have narrow edge bevels.

Just food for thought .... the bottom line being any number of things could be going on when stropping depending on factors mentioned, which explains why different people seem to have different success with different techniques.
 
Just as stoning a bevel produces a 'scratch pattern' where the blade contacts the stone, a strop will produce a 'polish pattern' where the strop meets the blade. Using light-reflection, magnification or both, it's pretty easy to use the polish pattern to see where the honing/polishing action is produced.

I 'sneak up' on the stropping angle, starting intentionally at a too-low angle, iteratively raising the angle and observing the polish pattern until I've found the angle that indicates I'm stropping right to the edge.
 
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