Thread: Pasted Strops a rough guide

I think the main reason some tend to shun the pasted (leather, balsa [insert favourite substrate here]) strop is that t it can only be used with the spine leading.

So, what is the problem with that? Well, it's a fairly well known issue in the various industries that sharpening steel edges by abrading against the edge results in a smaller wire edge than when abrading with (or away if you will) from the edge. Shallow angle edges such as the ones we use with straight razors are unique to straights, the steel simply does not have the strength at those angles to perform as a cutting edge in common uses. For razors, we adapt by using leather strops, linen strops and the like to attempt to keep the edge straight and not folded over between shaves.

One could use a hard substrate for the paste and hone against the edge, and this is exactly what we do when we use a slurry on a hone. When lapping on a hard surface, the fine grit becomes difficult to deal with, unlike the slurry on a hone. Trying to mix up and hone with Chromium Oxide suspended in water on a piece of glass would be pretty challenging. Hones are not quite as smooth, the slurry is often the same material as the hone and so any failure of the slurry will be made up for by the substrate, which is also an abrasive.

At this point I hear the Jnat owners objecting as they use Nagura stones to create various grits of slurry and they indeed hone against the edge so in a technical sense they are "pasting" their hone with abrasives and honing with them against the edge, and by all accounts, this works great. (And this is really lapping as they are using a loose grit on a hard surface).

I personally use a hard knit wool surface on a hard substrate pasted with Chromium Oxide powder and do maybe 5 or 6 round trips, spine first, to remove any faint wire edges that may have occurred on my hones and I seem to have great results. In the past, I used a pasted strop for polishing and refreshing my razors (same Chromium Oxide) and at the time I was pleased with the results, but today I no longer find that edge suitable for me, and I tend to do everything on my finishing hones and just that light 5 or 6 passes on the wool strop at the end finishes it for me.

I have no scientific proof, but from all my experience in the gunshop, machine shop etc., even a paddle strop with leather will have a very slight give and tend to convex the edge slightly. The main problem for me is that extended honing in that direction will also tend to create wire/false edges that can become a problem which is why I personally avoid it now.

In the end, there is no absolute right or wrong, run whatcha brung, and if it works for you, great... but never be afraid to try another idea.... for you it might just work, and as it is your shave and not mine... that's all that matters. But we need to keep universally accepted knowledge in mind. We know that honing against an edge results in a reduced wire edge, we know that honing away from an edge results in more pronounced wire edges.

Please note, all types of honing will result in wire edges if you take it that far... attempting to sneak up on that very moment, when honing a straight razor, without going too far, and creating a wire edge, is what it is all about. We all have our pet ways of doing that job, and with experience, an open mind, not to mention time, we eventually get better at it.

Regards

Christian

Wire edge, perhaps with lower grits and not alternating sides. But not at sub-micron grits.

Convexing a bevel is a good thing, not a problem. Honing edge leading, on film, over a sheet of paper on a glass substrate, will convex an edge.

The problem most folks have with paste, is making too big a jump and expecting too much from paste, without a progression. An 8-12k jump to 30k is a large jump, especially after a 4k jump from 4-8k progression.

A handful of pasted laps and expecting a magic edge is just not realistic.

That, and it is not just about grit size.

Originally Posted by Euclid440

Wire edge, perhaps with lower grits and not alternating sides. But not at sub-micron grits.

Convexing a bevel is a good thing, not a problem. Honing edge leading, on film, over a sheet of paper on a glass substrate, will convex an edge.

The problem most folks have with paste, is making too big a jump and expecting too much from paste, without a progression. An 8-12k jump to 30k is a large jump, especially after a 4k jump from 4-8k progression.

A handful of pasted laps and expecting a magic edge is just not realistic.

That, and it is not just about grit size.

Well, if you jump from a 12kSS... thas 12k Jis.. approx 15k... then, if we follow that rule that you should be safe if jump to a grkt thats the double than last... then .5 CrOx (30k) sould be safe... rigth? Then you can go to .3 CrOx and then .1 FeOx....
Is my theory flawed?