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Post by larason2 on May 8, 2024 19:36:33 GMT
That's a tricky question to answer! Traditional Japanese polishing advocates an open grit technique, where you never push too hard. This reveals the underlying details in the hamon. However, there's a spectrum of how "open grit" or burnished the piece is, with trained togishi being able to make them the most open grit/detailed. So if you don't push hard or burnish, you don't really get a smooth surface until you use finishing grits, which are usually over 10,000 (usually some kind of suita or uchigumori). That will give you a sashikomi/kasumi finish, and usually it looks matte if you look at it straight on, looks like a mirror if you look at it from the side. However, I've used uchigumori stones on copper, and they still give scratch lines there, so they are not so fine that they will really give a perfectly smooth surface. However, on steel I think the lines fill in with clay or clay like particles from the stone, and that is what makes it perfectly smooth.
That being said, you can get a burnished mirror surface easily on almost any stone over about 5000 if you push hard. The Japanese use ~500 grit/2000/~5000 all synthetic, then 1000 and 1500 sandpaper lubricated with mineral oil, then burnish with a migakibo/burnishing spatula. This gives a perfectly mirror finish that also reveals a little bit of the underlying detail. However, you can also just use a stone up to about 2000-3000 grit, then burnish with a burnishing spatula if you want zero of the underlying detail! These aren't my favourite finishes. For the Japanese technique, you need to use tsunoko (powdered deer antler) to remove the oil you used for the sandpaper, and Ibota (powdered shellac) to lubricate the stylus shook over the piece in a cloth bag, otherwise it doesn't turn out right (I've tried!). With all that work though, I'd almost rather just give it a proper polish! That's the only way to get the three classic Japanese "layers" on a sword though.
So the TLDR is that you can mirror it with any stone with a grit over about 5000, but you have to push hard, that's not quite traditional in any sense. You don't even have to go that high if you're just going to buffer or burnish it. If I was going for a detail-less burnished polish, I wouldn't waste time with stones at all. Sandpaper all the way with oil, and make it shiny with a burnishing spatula or a buffer! I'd probably be one of the ones they find a few hours later with a knife blank in the left side of my chest if I tried to use a buffer, so that's why I'd go with a spatula! They are pretty easy to use and foolproof if you're burnishing, though not nearly so quick.
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Post by mrstabby on May 9, 2024 8:35:07 GMT
OK, so what's a burnishing spatula? Explain, EXPLAIN!
Something else I wondered, since natural stones aren't PH neutral, that could also make the grain pop more on natural stones if they were slightly on the acidic side, right? I wonder how much off neutral - couldn't find anything beside "slightly acidic", not really a good measurement that.
I am so stupid.... I have new straight razors and need to sharpen them so I was planning on buying some more stones because I need to go much finer than my finest diamond stone and I also need something wider to get the bevel 100% straight. I have a setup for sandpaper I totally forgot about! I have even bought carbide sandpaper up to 10000grit for exactly that reason and forgot.... Yeah, sandpaper works, and it's cheaper. Glass plate and double sided tape and you're set. Thanks for reminding me. Sometimes you are so set in one direction you don't even realize.
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Post by larason2 on May 9, 2024 15:37:50 GMT
It's actually just any bit of hardened steel, though preferably tool steel. A migakibo is what the Japanese use, but you can use almost anything that fits the bill. For instance the side of a screwdriver blade tht's been smoothed out, or the rod, a knife honing rod, an old dull knife blade, a worn drill bit, etc. You can also just buy a piece of carbon steel or tool steel and harden the tip with a torch and some water. Polish the edge so it's smooth, and there you go. It won't turn out perfect, but it will be close, then you can do final polishing with a bit of meguiar's polishing paste, or similar.
pH is a very complex topic for stones. Japanese stones range from quite basic (most of them) to slightly acidic (hazuya). By by acidic, we're saying pH 6.8 in my tests. pH doesn't work for stones the way it does for other things though. The clay and clay like particles in stones get a lot of positive charge from groundwater, so you have to think of them more like lewis acids and bases (proton donor, proton acceptor). The positive charges on the clay actually coordinate other positively charged ions in solution, such as ionic metals and the surface of the metal you're polishing. So the clay and clay like particles stick to the blade and contribute to the aesthetic you're creating, assuming you're going for an open grain finish. These adhesion reactions are very durable, they can last years, but eventually they dry out and flake off into dust. The ability of stones to bring out detail in the blade relies partly on this. Then we have etching. Strong acids or bases can dissolve away some of the metal, and contribute to the effect, but I don't think there's much of this for ceramic stones. Rather, the metal gets worn away through abrasion (soft pressure), or grinding (hard pressure). Finally, there's patination. Patination results in a much more durable effect than the clay like particle adhesion, but it's harder to get! You need all the intermediaries in solution, and the right pH. So the citric acid washes or ferrous nitrate that are used probably create patination. I think the white colour of hazuya stones is also probably a mild patination. The traditional Japanese iron patina also does this. But it's pretty rare for Japanese polishing stones, I think. Most of the effect is clay-like particle adhesion.
Haha, don't feel stupid! I usually spend hours trying to do something without the right tools or materials, only to realize I actually bought them already, just forgot about it! I was trying for days to get clay to settle, then remembered we had already bought some alum for the garden! I was thinking of buying a new stone chisel, then remembered I had bought some old chisels for scrap metal from a flea market! There's so much overlap with these hobbies, you often find you already have the right thing!
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Post by mrstabby on May 26, 2024 18:31:42 GMT
I just remembered this, so if it behaves like you say (sticking for a while and flaking off) it's likely insoluable clay-iron complexes forming inside the microscopic surface imperfections or getting forced in while forming. Those complexes can degrade over time, losing or adding water of crystallization or oxidation so they change shape and don't fit any longer. Or the clay particles just aggregate and stick in the imperfections until they dry, but that would not keep that long, only until dry. Crystallisation water is bound more tightly and can even be bound indefinately on some complexes or crystals. Could also just be some compounds from the clay falling out of solution, would macroscopically act much the same way. Positive charges or ions can't get close to each other unless really forced to, it's more likely an exchange. The complex comes for example with a calcium ligand (clay is biomatter, can produce complexes, calcium is abundant in biological systems and is a good ligand with a 2+ charge), but it likes the iron better (who doesn't), so it kicks off the calcium and takes on an iron becoming insoluable. I think you mixed up Brønsted and Lewis acids/bases, the Lewis definition is about electron transfer. But you would definately need something to take the iron atoms electrons to get some into solution - not that this takes much. The metal as a whole can't ever have any ionic properties since all atoms share electrons and they go where needed, only single atoms can - unless it's electrostatic but that would not last beyond a few hours or days max. Patination or passivation does need specific acids/salts at a specific pH. Some work, others don't (I think HNO3 and H3PO4 are used, with the latter producing iron phosphate, which is quite widely used). I would wager though that passivation does not happen while polishing even if the right materials were in solution, you'd polish it off while it is forming - they'd also likely be deep grey or black. If you ask me it is more likely different sequesterants available for the complex or different environmental factors (pH, more or less reduction potential of the solution, etc) leading to different colours. This is more guessing than knowing, but I have done a little bit of complex-chemistry, a lot more salt/crystal chemistry, I know they can even stick to glass and can change over time so it would fit. I doubt it's just clay sticking, that would be easy to wipe off with water or oil, crystals less so, complexes even less once they have formed.
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Post by larason2 on May 26, 2024 18:51:13 GMT
I'm pretty sure the effect depends on water, and involves a wide variety of clay or clay like particles, and the effect is dependent on coordination of the charges of the iron on the surface, clay or clay like particles, and other ions. I'm not sure what role the water plays, perhaps helping the clay form a crystal as you say, though the solubilization of positively charged ions in solution also seems to happen if there is plenty of excess water, so I'm not exacty sure.
Anyway, my beliefs regarding this are the result of many different related observations. One is we know positively charged ions like lead are captured by clay containing solutions, and they release the lead on exposure to an acid, as this has been a cause if lead poisoning after consuming clay, and there's lots of papers that bavk this up. Next we know that relatively bulky positively charged ions like methylene blue stick to steel (in the presence of clays), and this has messed up many scientific observations in the past. Next we know that what the Japanese do when polishing their swords comes off over time and the sword needs to be repolished, as the Honami state this as why they have to be continually employed by the government to maintain historic swords. My own observations is that stones of different colour slurries impart different looks to the sashikomi that is thereby produced, and we know that because of groundwater, the only elements left in stones that produce colour are relatively insoluble ones like the transition metals. So it makes sense that the clay is probably somehow involved in adherence of methylene blue, etc. on the surface of steel. In my own experience, the aesthetic of a traditionally polished sword can change over months, not just years, I guess depending on what clay or clay like particles and what other ions are involved. Because the process requires water, I'm guessing that it is somehow involved in the adhesion of the clay and ions, and that as it dries the clay or clay crystals fall off, but I don't know enough to know exactly how this works. I'm assuming there must be removal of material, because the same stone that produces a smooth surface on steel produces a scratched surface on copper, so the difference must be the deposition of something in the grooves that should be otherwise generated (with uchigumori stones).
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Post by mrstabby on May 26, 2024 19:02:58 GMT
Anyway, my beliefs regarding this are the result of many different related observations. One is we know positively charged ions like lead are captured by clay containing solutions, and they release the lead on exposure to an acid, as this has been a cause if lead poisoning after consuming clay, and there's lots of papers that bavk this up. You exactly describe what complexes do, they are ion exchangers, and clay is full of organic complexes to begin with. Depending on pH and available ligands they exchange theone they have captured for something new. Like EDTA for example, citric acid is also a 2-pronged sequestrant, a weak one, but it can do complexes. Yes it would depend on water for everything, as an exchange medium or intermediate pool for the loose salt ions.
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Post by treeslicer on May 28, 2024 16:18:58 GMT
It's actually just any bit of hardened steel, though preferably tool steel. A migakibo is what the Japanese use, but you can use almost anything that fits the bill. For instance the side of a screwdriver blade tht's been smoothed out, or the rod, a knife honing rod, an old dull knife blade, a worn drill bit, etc. You can also just buy a piece of carbon steel or tool steel and harden the tip with a torch and some water. Polish the edge so it's smooth, and there you go. It won't turn out perfect, but it will be close, then you can do final polishing with a bit of meguiar's polishing paste, or similar. pH is a very complex topic for stones. Japanese stones range from quite basic (most of them) to slightly acidic (hazuya). By by acidic, we're saying pH 6.8 in my tests. pH doesn't work for stones the way it does for other things though. The clay and clay like particles in stones get a lot of positive charge from groundwater, so you have to think of them more like lewis acids and bases (proton donor, proton acceptor). The positive charges on the clay actually coordinate other positively charged ions in solution, such as ionic metals and the surface of the metal you're polishing. So the clay and clay like particles stick to the blade and contribute to the aesthetic you're creating, assuming you're going for an open grain finish. These adhesion reactions are very durable, they can last years, but eventually they dry out and flake off into dust. The ability of stones to bring out detail in the blade relies partly on this. Then we have etching. Strong acids or bases can dissolve away some of the metal, and contribute to the effect, but I don't think there's much of this for ceramic stones. Rather, the metal gets worn away through abrasion (soft pressure), or grinding (hard pressure). Finally, there's patination. Patination results in a much more durable effect than the clay like particle adhesion, but it's harder to get! You need all the intermediaries in solution, and the right pH. So the citric acid washes or ferrous nitrate that are used probably create patination. I think the white colour of hazuya stones is also probably a mild patination. The traditional Japanese iron patina also does this. But it's pretty rare for Japanese polishing stones, I think. Most of the effect is clay-like particle adhesion. Haha, don't feel stupid! I usually spend hours trying to do something without the right tools or materials, only to realize I actually bought them already, just forgot about it! I was trying for days to get clay to settle, then remembered we had already bought some alum for the garden! I was thinking of buying a new stone chisel, then remembered I had bought some old chisels for scrap metal from a flea market! There's so much overlap with these hobbies, you often find you already have the right thing! I just remembered this, so if it behaves like you say (sticking for a while and flaking off) it's likely insoluable clay-iron complexes forming inside the microscopic surface imperfections or getting forced in while forming. Those complexes can degrade over time, losing or adding water of crystallization or oxidation so they change shape and don't fit any longer. Or the clay particles just aggregate and stick in the imperfections until they dry, but that would not keep that long, only until dry. Crystallisation water is bound more tightly and can even be bound indefinately on some complexes or crystals. Could also just be some compounds from the clay falling out of solution, would macroscopically act much the same way. Positive charges or ions can't get close to each other unless really forced to, it's more likely an exchange. The complex comes for example with a calcium ligand (clay is biomatter, can produce complexes, calcium is abundant in biological systems and is a good ligand with a 2+ charge), but it likes the iron better (who doesn't), so it kicks off the calcium and takes on an iron becoming insoluable. I think you mixed up Brønsted and Lewis acids/bases, the Lewis definition is about electron transfer. But you would definately need something to take the iron atoms electrons to get some into solution - not that this takes much. The metal as a whole can't ever have any ionic properties since all atoms share electrons and they go where needed, only single atoms can - unless it's electrostatic but that would not last beyond a few hours or days max. Patination or passivation does need specific acids/salts at a specific pH. Some work, others don't (I think HNO3 and H3PO4 are used, with the latter producing iron phosphate, which is quite widely used). I would wager though that passivation does not happen while polishing even if the right materials were in solution, you'd polish it off while it is forming - they'd also likely be deep grey or black. If you ask me it is more likely different sequesterants available for the complex or different environmental factors (pH, more or less reduction potential of the solution, etc) leading to different colours. This is more guessing than knowing, but I have done a little bit of complex-chemistry, a lot more salt/crystal chemistry, I know they can even stick to glass and can change over time so it would fit. I doubt it's just clay sticking, that would be easy to wipe off with water or oil, crystals less so, complexes even less once they have formed. I'm pretty sure the effect depends on water, and involves a wide variety of clay or clay like particles, and the effect is dependent on coordination of the charges of the iron on the surface, clay or clay like particles, and other ions. I'm not sure what role the water plays, perhaps helping the clay form a crystal as you say, though the solubilization of positively charged ions in solution also seems to happen if there is plenty of excess water, so I'm not exacty sure. Anyway, my beliefs regarding this are the result of many different related observations. One is we know positively charged ions like lead are captured by clay containing solutions, and they release the lead on exposure to an acid, as this has been a cause if lead poisoning after consuming clay, and there's lots of papers that bavk this up. Next we know that relatively bulky positively charged ions like methylene blue stick to steel (in the presence of clays), and this has messed up many scientific observations in the past. Next we know that what the Japanese do when polishing their swords comes off over time and the sword needs to be repolished, as the Honami state this as why they have to be continually employed by the government to maintain historic swords. My own observations is that stones of different colour slurries impart different looks to the sashikomi that is thereby produced, and we know that because of groundwater, the only elements left in stones that produce colour are relatively insoluble ones like the transition metals. So it makes sense that the clay is probably somehow involved in adherence of methylene blue, etc. on the surface of steel. In my own experience, the aesthetic of a traditionally polished sword can change over months, not just years, I guess depending on what clay or clay like particles and what other ions are involved. Because the process requires water, I'm guessing that it is somehow involved in the adhesion of the clay and ions, and that as it dries the clay or clay crystals fall off, but I don't know enough to know exactly how this works. I'm assuming there must be removal of material, because the same stone that produces a smooth surface on steel produces a scratched surface on copper, so the difference must be the deposition of something in the grooves that should be otherwise generated (with uchigumori stones). Anyway, my beliefs regarding this are the result of many different related observations. One is we know positively charged ions like lead are captured by clay containing solutions, and they release the lead on exposure to an acid, as this has been a cause if lead poisoning after consuming clay, and there's lots of papers that bavk this up. You exactly describe what complexes do, they are ion exchangers, and clay is full of organic complexes to begin with. Depending on pH and available ligands they exchange theone they have captured for something new. Like EDTA for example, citric acid is also a 2-pronged sequestrant, a weak one, but it can do complexes. Yes it would depend on water for everything, as an exchange medium or intermediate pool for the loose salt ions.
FWIW, all the classic Jnats are slates, which are metamorphosed shales, which are petrified clays to begin with. Carry on, gentlecreatures.
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Post by larason2 on May 29, 2024 0:09:33 GMT
That's partialy true, but I've found out the naming of these kinds of stones is actually a huge mess! Claystone, siltstone, mudstone, shale, slate, argillite, limestone, sandstone, and many more terms are all kind of used to describe these stones that are on a big spectrum of composition and degree of metamorphization. Most of these have at least some clay in them, as well as some silaceous grit, but there's no standardization of naming conventions, and on the internet among stone enthusiasts, they use whatever name they wish! Still, these are the natural stones that most apply to sharpening and polishing. But you're right, basically all of them have clay in some form!
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Post by treeslicer on May 29, 2024 3:34:46 GMT
That's partialy true, but I've found out the naming of these kinds of stones is actually a huge mess! Claystone, siltstone, mudstone, shale, slate, argillite, limestone, sandstone, and many more terms are all kind of used to describe these stones that are on a big spectrum of composition and degree of metamorphization. Most of these have at least some clay in them, as well as some silaceous grit, but there's no standardization of naming conventions, and on the internet among stone enthusiasts, they use whatever name they wish! Still, these are the natural stones that most apply to sharpening and polishing. But you're right, basically all of them have clay in some form! Sorry. I oversimplified. I was using "slate" in a broad sense to explain that most Jnats were clays at some point, prior to low grade, mostly contact, metamorphism. Also, some of the Jnats are technically hornfels from higher-grade contact metamorphism, and some approach schists from the regional metamorphism. All sorts of seds were involved as parent material, too. The geology of Japan is appallingly complicated.
Can we agree that, in the beginning, a lot of igneous rock got weathered, and then plate tectonics did the rest?
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Post by larason2 on May 29, 2024 23:55:58 GMT
Ah, so you know a bit about Geology! I'm a neophyte to it mostly, having had to learn some because one of my new hobbies is scouring south western Manitoba looking for good polishing stones! Still, the best I've found aren't as good as my Japanese stones, of which I now have a sizeable collection! I went crazy and bought a lot of mostly koppa from various mines, so I have a pretty good spectrum of JNats to pick from now at various grits. The field of Geology is so vast though, just when I think I've seen them all, I find a rock that's totally different from all the ones I have! I like rock hounding though, and being able to use what I find to sharpen and polish swords is a fringe benefit!
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Post by LastGodslayer on Jun 1, 2024 22:02:06 GMT
This is like... the best thread ever!
...carry on...
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