Is stropping really harmful for edge retention?

[Jason B.]

Ive asked many chefs why no one strops for sashimi knives/kitchen knives. It weakens the edge.

as a sushj chef, my edge needs to stay sharp at least 8 hours, microbevel is the way to go.

stroping works, but for razors and knives that are only for looks and showing off.

I sharpen for chefs all day long, usually because they can't sharpen...

 

[hank_rearden]

question: let's assume i can get a flat sharpening bevel and not a convex (i swear i'm able to avoid a convex during sharpening.) how come the edge "bites" on to the leather at a higher angle than the sharpening bevel? i'm forced to strop at the bite angle. will this eventually form a convex?

 

[Chris "Anagarika"]

question: let's assume i can get a flat sharpening bevel and not a convex (i swear i'm able to avoid a convex during sharpening.) how come the edge "bites" on to the leather at a higher angle than the sharpening bevel? i'm forced to strop at the bite angle. will this eventually form a convex?

The answer is here: www.bladeforums.com/forums/showthread.php/750008-Stropping-angle-plus-pressure

And yes, it will convex the bevel, either by 'rounding off' the apex or the bevel shoulder.

 

[Jason B.]

If you are freehand sharpening you are convex sharpening, no avoiding it.

 

[Obsessed with Edges]

question: let's assume i can get a flat sharpening bevel and not a convex (i swear i'm able to avoid a convex during sharpening.) how come the edge "bites" on to the leather at a higher angle than the sharpening bevel? i'm forced to strop at the bite angle. will this eventually form a convex?

Assuming you mean a more obtuse (wider) angle, when saying 'higher angle', and that you're noticing the 'bite' with an edge-trailing stroke? If so, this sounds like you're feeling a burr that's angled or curled downward into the strop and 'digging into' the leather (if this is happening, you'll likely see some streaks being scratched into the leather, by the burr's rough edge). This is common, at least in my case; but that's what stropping is meant to fix anyway.

As mentioned, stropping on any soft(ish) substrate will produce some convex, as will any freehand sharpening/stropping technique. Nobody is perfect, in their ability to maintain an exactly consistent angle, though I'm sure some experienced sharpeners may come closer than others.


David

 

[Threethreethree]

If metal fatigue and burnishing are such a big deal, how about ceramic sharpeners ?
Rod type ceramic puts waaaay more pressure on a bevel than any strop would do yet i never heard ceramics were bad for edge retention.
But again just like for the strop i clearly lack comparison points as i sharpen using ceramics and strop since something like 13 years.

 

[Obsessed with Edges]

If metal fatigue and burnishing are such a big deal, how about ceramic sharpeners ?
Rod type ceramic puts waaaay more pressure on a bevel than any strop would do yet i never heard ceramics were bad for edge retention.
But again just like for the strop i clearly lack comparison points as i sharpen using ceramics and strop since something like 13 years.

This is why I've sort of drifted away from using ceramics very often. The rod-type ceramics, as you mentioned, put an awful lot of pressure on an edge. That creates burrs (weakened steel) which must then be removed. This is basically the polar opposite of 'edge retention', and instead necessitates removing more damaged steel from the edge. Stropping is just the ticket for doing that; i.e., removing the weakened steel instead of creating it in the first place.

Almost any sharpening/honing activity must remove some steel, else it'd be wasted effort most of the time. There is some value in stropping's ability to realign an edge with minimal abrasion (removal of metal). But, more often than not, some actual honing will be needed to get an edge back in shape. That's just the nature of maintaining edges that actually get used; there's always going to be some wear.


David