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Different grinds suit different finishing?

As I've now pretty much moved from synthetics to natural stones I've found that antique blades that are wedge, almost wedge up to half hollow are better with a coticule only edge and half hollows and upwards are better being finished on a Thuringian / Frankonian.
The sample size that leads me to this conclusion is quite small but it is noticeable (YMMV).

Have any of you noticed anything similar?
 
I've had similar oddities happen. I can't hone a wedge on a coticule or Jnat, just quit attempting and use my Norton's and finish water only Jnat. I'm sure it's a minor adjustment but this give me an excuse to use my Norton.
 
I have found that certain razors will take more time on certain stones, but I have not yet found that the eventual results are any less than I would desire. I had chalked this up to my own shortcomings as a honer. (I am human, no?) On a better day, I might have better results.

I also have had good luck giving a difficult razor daily "touch-ups" until it's up to snuff.
 
I've found that the old big sheffield wedges seem to prefer somewhat coarser hones than the thin german full hollows. I don't know if it's because of the steel, or because of the grind. I suspect that the edge takes a little damage each pass on the hone just from random imperfections in the hone and stone and slurry. Under normal circumstances we don't notice because (a) the damage is slight and random and (b) it promptly gets honed away. But if we don't remove enough steel each pass then the damage isn't honed away and accumulates from pass to pass. Those big wedges with those huge bevels need a lot of metal removed each pass to keep ahead of the background level of edge damage, and need a coarser grit hone because of this.

For going to finer grits, I've found that they do well with a pasted hanging strop.
 
As I've now pretty much moved from synthetics to natural stones I've found that antique blades that are wedge, almost wedge up to half hollow are better with a coticule only edge and half hollows and upwards are better being finished on a Thuringian / Frankonian.
The sample size that leads me to this conclusion is quite small but it is noticeable (YMMV).

Have any of you noticed anything similar?

Have you finished on coticule, shaved, touched up on Thuri/Frank, shaved, and noticed the shave degrade? If not, I'd just suspect that the fact that heavier grinds take a lot longer to hone are just meaning the coarser/faster finish nets you a more thoroughly finished razor.

That said, Wedge and Near wedge blades never give me the closeness I want from a shave and always feel like they're fighting through or scraping along my beard. They don't have the clean cut of hollow grounds... that said, I don't find much if any difference between the various hollow grounds. 1/4 hollows and some even less hollow shave excellently for me. But I've tried wedges that I've honed that prove themselves very sharp, wedges pro honed on Charnleys, Naniwa 12k's, Shapton 30k's, Various pastes, and more. None give me the shave I get from hollow grounds. It seems once the line between bevel and grind starts to blur (and no, the fact that taping allows a clean "bevel" on a wedge doesn't seem to change this) on a razor, I find it just doesn't shave well for me. Others love them, to each his own.
 
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I agree that different razors will hone different on different stones.
That being said I finish 99% of all razors on Jnats and they take great edges. I am not convinced there is any correlation to the grind, but I am sure there is a correlation to the type of steel.
 
I agree that different razors will hone different on different stones.
That being said I finish 99% of all razors on Jnats and they take great edges. I am not convinced there is any correlation to the grind, but I am sure there is a correlation to the type of steel.
Yes, I think it's a matter of steel.

My point of view is that ther eis differences, but those differences is in how you can use the stone on a certain razor.
Basically hones removes metal.
They do it differently & some steel removes a bit differently then other types.
Some matches better to one another, but any good hone will hone up any good steel/razor. It's a matter of finding what works for that particular razor.
 
That being said, what would the key differences be between Sheffield and Solingen steel, same grind, size and vintage. I gave them the same treatment and the Sheffield just is not getting as keen as the Solingen... (not sticking to the same laps, but the same progression of stones for bevel setting and on...)
 
It is especially glaring when you start sharpen knives from different steels on Jnats, then you will see that one stone does not work equally for all steels.

Ah, very good point. I notice differences but just took it more of being careful of honing since I hone on naturals. I have a Sta Sharp and Craftsman (same steel) and though they take a superlative edge they do require some adjustments to how many reslurries I do.
 
I've found that the old big sheffield wedges seem to prefer somewhat coarser hones than the thin german full hollows. I don't know if it's because of the steel, or because of the grind. I suspect that the edge takes a little damage each pass on the hone just from random imperfections in the hone and stone and slurry. Under normal circumstances we don't notice because (a) the damage is slight and random and (b) it promptly gets honed away. But if we don't remove enough steel each pass then the damage isn't honed away and accumulates from pass to pass. Those big wedges with those huge bevels need a lot of metal removed each pass to keep ahead of the background level of edge damage, and need a coarser grit hone because of this.

For going to finer grits, I've found that they do well with a pasted hanging strop.

This needs to be quoted, as I believe it to be very true, and generally completely overlooked. Honing strokes in the stropping direction remedify the situation, but it introduces disadvantages of it's own. The use of a secondary bevel is another option to work around the issue, and a very effective one at that. It works on similar principles as the pasted strop, focussing on metal removal at the very edge.

By the same principles, hones with very hard particles will cut shallower (smoother?) on a wide bevel than on a very narrow bevel, due to the different PSI. Maybe that can be partially compenated by adjusting the pressure to the situation at hand.

Kind regards,
Bart.
 
By the same principles, hones with very hard particles will cut shallower (smoother?) on a wide bevel than on a very narrow bevel, due to the different PSI. Maybe that can be partially compensated by adjusting the pressure to the situation at hand.

The problem is that wide bevels tend to occur on wedges and not full hollows, which makes direct comparisons difficult. When you use pressure on a wedge then the edge presses into the hone along with the rest of the bevel, so it cuts faster and that's about it. When you add pressure on a full hollow the blade flexes, lifting the edge off the hone a bit. You'd think that this would simply mean that the edge doesn't get honed and the back of the bevel gets honed more aggressively instead, and you'd be right... However we know from experience that using a bit of pressure on the blade when honing is very bad for the edge, which means that something else is going on.

I think the other thing that happens to a full hollow when under pressure is that because the flex lifts the leading edge off the hone, the swarf no longer goes harmlessly over the top of the edge. Instead it is swept between the edge and the hone, causing the edge to bang into it and climb up over it, and in doing so it actually damages the edge. I think this is one of the mechanisms for the "random damage from the hone" that we see, only only this time it's not so low-level or random, and because the edge isn't touching the hone this damage isn't even cleaned up a little bit. The net result is a munged edge.

Verhoeven's "Experiments in Knife Sharpening" monograph had some electron microscope shots of blades that had been honed in a forward direction and those that had been honed in a stropping direction, and the hone-stropped blades had much more damage on their edges than the forward-honed blades, from the edge banging around on the swarf on the stone. This isn't exactly the same situation as I described but the effect is similar.
 
I would think that the effect of blade flexing from extreme pressure would be more akin to the opposite of taping rather than blade damage.
 
I would think that the effect of blade flexing from extreme pressure would be more akin to the opposite of taping rather than blade damage.

It takes enough pressure to lift the edge clear of the swarf to achieve this; if you're not using enough pressure then the edge will hit the swarf and ride over it. How much pressure is needed to make this harmless depends on the size of the bevel and the size of the swarf particles. If you're not pressing evenly across the entire blade then you can run into situations where one part of the blade is flexed enough to safely ride the swarf, but some other part isn't flexed enough and it being damaged. Or if the blade shifts on the hone while you're applying pressure then you can damage it, though. This technique of applying pressure to a full hollow is a useful technique if you've got one that has a wide bevel - you can press down a bit in the middle as evenly as you can, and hone the back of the bevel away so that it doesn't slow you down as much when you get to the final edge. If you're one of the guys that doesn't like tape, then this is a way to get a similar effect. But you have to be careful, and you can't do this once you get past the bevel-setting stage or you'll risk killing the edge.

One thing I've found with using tape is that the plastic swarf from the tape is much larger than the metal swarf from the blade, so if you're at the polishing stage and still using tape (common when honing pattern-welded blades or gold washed blades) then you have to be very mindful of your pressure.
 
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