Dredging Up Handle Wood

Aluminum oxide and silicon carbide both come in a variety of grades, and different classifications of bond are also subject to a lot of variations, including specific composition, the pressure during molding, firing temperature, availability of oxygen during firing and how that reacts with the abrasive and binder, the grit/bond ratio, and so on. But nearly all synthetic Japanese water stones are using aluminum oxide as the abrasive, with most of the remainder being silicon carbide. Most of those stones are either a vitrified bond, producing a stone that works best when soaked and sheds grit from pressure that breaks the weak bond used, or a magnesia bond which breaks down with exposure to water, producing the shedding action by that method. Neither of those are enhanced by the presence of wrought iron, which is the crux of what I've been saying the whole time.

I do hope this doesn't come off as overly contentious, it's just that I've put a lot of time both in technical research and experimentation into figuring out how abrasives are formulated and function, and what variables influence what factors. This is all a side point to the fact that you like how they work, including the sensation/feedback of the wrought iron being abraded by a soft stone. :)

Slurry-forming stones are excellent as an intermediary polishing stone, as the free grains plowing into the apex keep it from forming a wire edge or tenacious burr, freeing you from having to fight it during final honing. But for the final step a hard stone usually works best for creating a crisp apex, and for that stage I like to use sintered ceramics. Hard natural stones were typically prized for that stage for the same reason. :thumbsup:
 
The claim you make then, as far as the crux of the matter and leaving aside the many tangential points, as I read it, feel free to correct, is that wrought iron has no effect in the sharpening process, more pointedly the functioning of the stone irregardless of the stone in question. It's a bold proposition but OK seems clear enough.
 
Basically, it'll affect the feedback you feel, but it's not going to fundamentally change how the stone is performing, especially in terms of the cutting speed at the edge itself or any slurry-forming dynamics. The iron's just a softer material and so the stone will feel more aggressive when contacting it, but that's not the stone changing. That's the workpiece material changing.
 
That the stone has an effect on the metal but is unaffected, outside conventional parameters, by it no matter the character of the stone, no matter the metal, steel or iron.
 
FortyTwoBlades said:
Aluminum oxide and silicon carbide both come in a variety of grades, and different classifications of bond are also subject to a lot of variations, including specific composition, the pressure during molding, firing temperature, availability of oxygen during firing and how that reacts with the abrasive and binder, the grit/bond ratio, and so on. But nearly all synthetic Japanese water stones are using aluminum oxide as the abrasive, with most of the remainder being silicon carbide. Most of those stones are either a vitrified bond, producing a stone that works best when soaked and sheds grit from pressure that breaks the weak bond used, or a magnesia bond which breaks down with exposure to water, producing the shedding action by that method. Neither of those are enhanced by the presence of wrought iron, which is the crux of what I've been saying the whole time.

I do hope this doesn't come off as overly contentious, it's just that I've put a lot of time both in technical research and experimentation into figuring out how abrasives are formulated and function, and what variables influence what factors. This is all a side point to the fact that you like how they work, including the sensation/feedback of the wrought iron being abraded by a soft stone. :)

Slurry-forming stones are excellent as an intermediary polishing stone, as the free grains plowing into the apex keep it from forming a wire edge or tenacious burr, freeing you from having to fight it during final honing. But for the final step a hard stone usually works best for creating a crisp apex, and for that stage I like to use sintered ceramics. Hard natural stones were typically prized for that stage for the same reason. :thumbsup:
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Do you have any data to back up the claim that free grains plow into the edge and prevent wire edges?
 
With a slurry you have what's known as three body abrasion. Your bevel is sitting on a layer of silt, the grains of which are rolling like ball bearings between the knife and the face of the stone, which is what's responsible for the smooth matte finish such stones produce, similar to a fine bead blasted finish (of course increasing in polish as you go up in grit and becoming increasingly shiny/reflective.) Cliff Stamp has written a lot on the dynamic, and I've personally found that my experiences align with his observations.
 
Here are some close-ups of a bevel produced with a slurry and with clear water, the first two going from slurry to no slurry and the last two the reverse, no slurry to slurry. I guess these are shots of a straight razor, like the one you've got garry3.
 
FortyTwoBlades said:
With a slurry you have what's known as three body abrasion. Your bevel is sitting on a layer of silt, the grains of which are rolling like ball bearings between the knife and the face of the stone, which is what's responsible for the smooth matte finish such stones produce, similar to a fine bead blasted finish (of course increasing in polish as you go up in grit and becoming increasingly shiny/reflective.) Cliff Stamp has written a lot on the dynamic, and I've personally found that my experiences align with his observations.
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So only those grains trapped between the stone and steel cut or also the free flowing ones that plow into the edge?
 
The ones that plow into the edge technically cut to some degree, and are what helps prevent a wire edge from forming, but also what makes forming a crisp apex on a muddy stone a challenge. Usually either edge-trailing strokes must be used, or the stone flushed free of slurry and extremely light passes used.
 
FortyTwoBlades said:
The ones that plow into the edge technically cut to some degree, and are what helps prevent a wire edge from forming, but also what makes forming a crisp apex on a muddy stone a challenge. Usually either edge-trailing strokes must be used, or the stone flushed free of slurry and extremely light passes used.
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Edge trailing creates a burr and edge leading removes it or prevents it from forming, no?
 
garry3 said:
Edge trailing creates a burr and edge leading removes it or prevents it from forming, no?
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Yup. Which is what makes forming a crisp apex on a soft stone tough. If you use edge trailing strokes you have to stop just before forming a wire edge, which requires a lot of care.
 
Another way to describe the slurry's effect, it is making the bevel convex the most abrasion occurring at the edge and diminishing up the bevel, there goes your burr, there goes the crisp apex.
 
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