Thread: Identifying a convex bevel caused by extensive pasted stropping

The convexity occurs only over the last few microns from the edge, what I call micro-convexity. In my opinion, this will not cause any problems.

It is possible to form a foil edge when making the transition to micro-convex from a perfectly non-convex edge (e.g. from honing on a flat hone with no slurry). I suspect this is root of the belief that too much CrOx can cause harshness.

However, alternating between shaving and CrOx stropping should not form a foil, since shaving will knock it down before it becomes an issue.

IMO there's a lot of theories, a lot of conventional wisdom, some dogma, and even some old wive's tales around here re stropping and honing (anyone remember "resting" the blade for 24 hours, which was a thing when I first joined here around 2010?), and then there are people like you (and sometimes me and others) who don't know any better getting great results by going against conventional wisdom.

This is not to denigrate the awesome amount of real expertise that many experts in this game bring to the forum from years of real-world testing and experience, mind you. I've learned almost all I know about str8s (and the little I know about honing and stropping) from this forum, but ever so often I find a different route that works for me. I too tend to hit the CrOx strop probably more than some others, though not as much as you. I feel that as long as I keep it "tight and light" on the strop, it minimizes the potential for convexing, but if I paste-stropped as much as you, I'd probably occasionally hit a few laps on that 12k just for good measure.

Ultimately, the shave is the only real test, and as I've repeated here before, a quote that is not mine: There are many roads to sharp.

Due to this thread (thanks op) I have been stropping after every shave on iron oxide and then leather. The last few days have been excellent edges and shaves. I'll keep this routine up for the sake of science. Lol.

These two images show a cross section of an edge after a Shapton 16k and then after 500 laps on CrOx on leather.



There is no convexity after the 16k. After the CrOx stropping, convexity is created only within a few microns of the edge, even after 500 laps.

Seeing that much magnification makes me wonder how we even shave with a straight looks better with a 40x loupe

Originally Posted by Steel

Due to this thread (thanks op) I have been stropping after every shave on iron oxide and then leather. The last few days have been excellent edges and shaves. I'll keep this routine up for the sake of science. Lol.

Edges seem to be getting smoother and smoother. Nothing but BBS all week with no touch ups! I'm liking this IronOxide .09 micron paste from Larry @ whippeddog.

First of all, COOL PIC!! Do UWO just let you scan whatever you like? would love one of those! Second, where is the difference in the 2 pics? I don't see any convexity, all I see is that it looks like the edge has become more fragile with pieces hanging off? I do find Crox harsh after a while though. If I use it more than twice to touch up I feel like it is not as buttery smooth as it usually is, it still stays sharp though no doubt. Maybe it is because my razors are honed on a coticule though I don't know.

Originally Posted by Kefka

...where is the difference in the 2 pics? I don't see any convexity,

These are the images with angle measurements included. The native angle of this razor is 16.5 degrees.

Originally Posted by Kefka

all I see is that it looks like the edge has become more fragile with pieces hanging off?

Stropping on leather leaves particles on the edge, for example the one in the foreground. There is a bit of a foil on this, as it was given 500 laps consecutively without being used. The edge would be much smoother if I had repeatedly alternated between use and 10 or 15 laps on the CrOx. In my experience it would convex faster also, as shaving will dull the edge.

Originally Posted by Kefka

I do find Crox harsh after a while though. If I use it more than twice to touch up I feel like it is not as buttery smooth as it usually is, it still stays sharp though no doubt. Maybe it is because my razors are honed on a coticule though I don't know.

The Coticule edge already has convexity due to the use of slurry, so it will become "too convex" much sooner than the Shapton edge.

Ah ok now I do of course see the angle difference, was just hard to spot without the guide lines! Thank you for posting this it's very interesting. I was under the impression that the coticule edge would be just as straight as an edge off a synthetic hone as when you go through the dilution stages you get less and less slurry dulling until you finally arrive at water only and you polish the edge out to its max keenness limit. May this is incorrect though I am open to correction!

Originally Posted by fuzzychops

The convexity occurs only over the last few microns from the edge, what I call micro-convexity. In my opinion, this will not cause any problems.

It is possible to form a foil edge when making the transition to micro-convex from a perfectly non-convex edge (e.g. from honing on a flat hone with no slurry). I suspect this is root of the belief that too much CrOx can cause harshness.

However, alternating between shaving and CrOx stropping should not form a foil, since shaving will knock it down before it becomes an issue.

Just for clarification, is the "foil" a micro version of the "wire" you can get honing knives?

Dave