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Post by Bob B on Jul 30, 2021 7:42:09 GMT
Is there anybody that is aware (for certain) of sword producers/smith's that oil quench blades? I'm just curious to see and get a idea on what or how many Smith's do this....if so is there a cost savings to oil quench vs. water?
Second question. Throwing all my preconceived notions out the window, what are some telltale easy ways to spot oil quenching?
Thanks in advance,
Bob
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Post by Drunk Merchant on Jul 30, 2021 12:55:16 GMT
Part 1: The main difference is that oil cools slower due to lower specific heat and a high boiling point. That means oil forms much less martensite, that’s your trick for telling them apart. what does that mean in looks? Oil hamon will have a weak/diffuse nioguchi and no activities or nie whatsoever, water should have nie of some sort and activities be they hotsure, nijuba, inuzuma, or whatever, water quenching also leaves nie on the sword hada. Here is an example of an oiler: Note the weak nioiguchi and most importantly: the black oil stains above or below the hamon. Those are an unmistakable sign of oil quenching. Why does all of this matter? Amongst dealers oil quenching is considered undesirable and worth much less, it’s a modern industrial method and quite ugly in results. Apparently because the reduced edge hardening, they’re also far more prone to edge rolling and premature wear compared to say a konie hamon water quenched with utsuri supporting it. In fact, war era Japan, despite having impeccable oil quenching by modern standards, exelent geometry and modern steel for their oil quenched Showato found them disappointingly prone to edge damage and started pushing water quenched mantetsu and star gendai to fix what they saw as a crap sword problem. Who knows, maybe they’re wrong but a military as obsessed with swords as imperial Japan saying this makes me take it seriously. If you can pick between water quenched and oil of the same cost, go for water.
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Post by RufusScorpius on Jul 30, 2021 13:03:22 GMT
What, then, is the advantage of oil quenching in the industrial process? Water is cheaper than oil and has less environmental concerns, so it would seem to be the preferred choice, so then why use oil?
As they say in the halls of academia: "illuminate me".
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Post by Drunk Merchant on Jul 30, 2021 13:03:51 GMT
Part 2: Oiler spotting So as I mentioned, oil quenched will naturally have a weak nioiguchi. Lots of smiths and some scam artists get past that by FeCl 3 acid “enhancement” (etches sword metal so actually pretty bad for a blade), that brings out the nioiguchi and makes it a bit more confusing. Thankfully, there are tell tail signs: firstly, the hamon now is flat and visible in all lighting whereas a natural strong hamon is dynamic, subtle without incident light and brilliant and reflective when hit by incident light. Secondly, the acid etching can’t create activities, you’re still looking at a barren line of sorts and no nie will be found on the sword. Third and most important: the dark oil stains remain right above parts of the temper line. If you see those stains, it’s oil. Here’s a good example: Samurai Monkey in one of his scams tried to pass off an oil quenched showato as a gendai and acid dipped it. Note the hamon is flat, there are no activities or nie, and the dreaded oil stain. He tried to use a hadori to lighten it up but even so, the stain remains. Know how to spot it since it could save you thousands. By contrast, here is a generic water quenched sword, sashikomi poilish with no enhancement. Note the hamon glows with light, is subtle when not illuminated, the little dark nie grains scattered in the hamon and most importantly, no damned oil stains. Some water quenched may be nioi based, but they won’t have stains, will be defined, not hazy, and you probably will see some on the hada. Look for those little black nie grains, if you see them it’s almost certainly water quenched and traditional.
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Post by Drunk Merchant on Jul 30, 2021 13:12:24 GMT
What, then, is the advantage of oil quenching in the industrial process? Water is cheaper than oil and has less environmental concerns, so it would seem to be the preferred choice, so then why use oil? As they say in the halls of academia: "illuminate me". Yep, exactly, the reason they started making oilers, Murato swords and the like are better in that it’s far easier to mass produce. You don’t lose swords from quenching breakage, and because the slower cooling, you don’t need as much skill, and I guess from an industrial engineering standpoint it’s far more convenient a quencher. You can make a ton of oil swords, find more people qualified to make them so mass production wise, obvious advantage, even if the army (as the Mantetsu and Rikugun Jumei Tosho programs to make something better) thought them less effective in war. Water by contrast, it has an incredibly steep learning curve, few qualified for it, it’s a coolant that boils off fast and leaves steam all over so not as practical industrially, and worse yet, even a master smith will lose some swords in the production process to breakage from quenching. That said, the combination of a hard edge and springy ji, like with niedeki soshu swords with utsuri is really durable and where oil rolls, a good water will absorb the cut or at worst suffer bitty chips that can be polished out instead of compromising an entire edge with a roll. PS for everyone: This is another acid enhanced oil tempered sword you can practice oil spotting with True the acid made the hamon more defined, but it looks flat and painted on instead of being dynamic, has zero activities, and most importantly, not even cosmetic tampering could cover up the oil stains. If Samurai Monkey ever tries to sell you something like that saying it’s gendai or a family blade, walk away. Here is an unenhanced oil hamon by comparison, note it’s weak and diffuse
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tera
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Post by tera on Jul 30, 2021 17:21:55 GMT
This is an exceptionally informative thread, and exactly what we need. Thank you for your contributions, Undead Merchant.
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Post by RufusScorpius on Jul 30, 2021 17:57:20 GMT
Interesting. So basically the oil quenching has a wider tolerance of time/temperature for the quenching process that reduces the number of defects due to skill/training deficiencies on the manufacturing side in exchange for a (somewhat) lower quality product on the consumer end, albeit with a more consistent result. I wonder what the impact on the error rate would be if they used water quenching through an automated process and eliminate the human variables? In that system, you could very precisely control the water temperature, steel temperature, and quench time based on a feedback program algorithm. But then again, I doubt any smith could afford an automated process like that just to quench swords.
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tera
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Post by tera on Jul 30, 2021 18:13:00 GMT
I imagine each sword is different, even if only slightly. Supposing automation of the quenching method were possible, it would likely produce mixed results, on par or worse than a human smith.
Thankfully for the job market, not everything can be automated... yet.
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Post by Drunk Merchant on Jul 30, 2021 18:22:13 GMT
tera Thanks, I nearly fell into a bunch of oil scams when new to this(luck saved me) so just thought I’d share the easiest ways to tell if it’s oil or water so that people avoid frustration. It definitely could save money since while a water quenched Gendai gunto will go for 2-3k, a oil quenched Showato in fittings is low 1000s, so scammers like Monkey buy them for peanuts, spruce them with acid and hadori and then try to scam people into paying double for what it’s worth. @ RufusScorpius I bet a computer could handle it. True as Tera says the type of tamahagane/metal you use affects what temperatures you can use -I hear Masmune used milder steel so he could get it hotter and cool faster and still get tons of nie and utsuri for instance- but I’m sure a computer could handle it. I’m sure the people who actually do science in this like you could figure it out. Me? I just hoard and sometimes sell and know what looks right but not so much why. Also I bet standardized steel like in Mantetsu could solve your problems. As a side, water quenched Mantetsu might have industrial steel, but they still have activities, nie, and a defined hamon and no oil stains. So even if it isn’t a tamahagane blade, water quenching should lead to the water quenched look I described. Above is a Mantetsu for reference.
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Post by AndiTheBarvarian on Jul 30, 2021 18:24:58 GMT
Interesting. So basically the oil quenching has a wider tolerance of time/temperature for the quenching process that reduces the number of defects due to skill/training deficiencies on the manufacturing side in exchange for a (somewhat) lower quality product on the consumer end, albeit with a more consistent result. I wonder what the impact on the error rate would be if they used water quenching through an automated process and eliminate the human variables? In that system, you could very precisely control the water temperature, steel temperature, and quench time based on a feedback program algorithm. But then again, I doubt any smith could afford an automated process like that just to quench swords. Mass produced axe heads are heat treated this way afaik. Usually Euro swords are oil quenched too because it reduces failures and there is no need for the special katana effects.
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karl j
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Post by karl j on Jul 30, 2021 19:32:56 GMT
Undead, that mantetsu, looks very nice...
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Post by Drunk Merchant on Jul 30, 2021 19:48:24 GMT
My thoughts exactly. It’s an utter shame that they stopped making them after the war. I would argue they’re the finest production sword around and the best looking production too. Many are so good they can even earn art sword papers. www.japanese-sword-katana.jp/katana/1910-1040.htmAlso they did something funky with their alloy because unlike normal DH swords (which aren’t meant for freezing temps) these excelled in the frozen winter of Manchuria. I like to think of them as like Star Gendai (already excellent) but possibly marginally tougher, much easier to produce, and with all weather ability.
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Post by Bob B on Jul 30, 2021 20:49:11 GMT
Part 1: The main difference is that oil cools slower due to lower specific heat and a high boiling point. That means oil forms much less martensite, that’s your trick for telling them apart. what does that mean in looks? Oil hamon will have a weak/diffuse nioguchi and no activities or nie whatsoever, water should have nie of some sort and activities be they hotsure, nijuba, inuzuma, or whatever, water quenching also leaves nie on the sword hada. Here is an example of an oiler: Note the weak nioiguchi and most importantly: the black oil stains above or below the hamon. Those are an unmistakable sign of oil quenching. Why does all of this matter? Amongst dealers oil quenching is considered undesirable and worth much less, it’s a modern industrial method and quite ugly in results. Apparently because the reduced edge hardening, they’re also far more prone to edge rolling and premature wear compared to say a konie hamon water quenched with utsuri supporting it. In fact, war era Japan, despite having impeccable oil quenching by modern standards, exelent geometry and modern steel for their oil quenched Showato found them disappointingly prone to edge damage and started pushing water quenched mantetsu and star gendai to fix what they saw as a crap sword problem. Who knows, maybe they’re wrong but a military as obsessed with swords as imperial Japan saying this makes me take it seriously. If you can pick between water quenched and oil of the same cost, go for water. Thank you so so much for taking your time to explain this in the thead! The pictures really helped me put it together! I truly appreciate it. Thanks again and take care. Bob
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Post by treeslicer on Jul 30, 2021 21:28:26 GMT
................. while a water quenched Gendai gunto will go for 2-3k, a water quenched is low 1000s, so scammers like Monkey buy them for peanuts, spruce them with acid and hadori and then try to scam people into paying double for what it’s worth. Typo? I think you mean oil and 100s.
Well, I apologize for falling down on the job. I've said good things about water quenching (mostly with regard to Chinese folded blades) here for years, but given the number of smiths on the forum, I assumed you guys knew all this stuff about oil.
Besides my nihonto, I've got some very nice Chinese water-quenched blades which sold for very modest prices on eBay a few years ago. I'll try to get some photos up.
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Post by Drunk Merchant on Jul 30, 2021 23:34:59 GMT
Eh, by low 1000s I mean genuine Japanese type 98 gunto. Even if they have Showato blades, their decent fittings and historical importance means you can move a Shingunto with an oiler blade for over 1000$. Not much more mind you. I’ve got antique goggles over everything I do.
Also good catch, meant oil.
Granted if it’s a oil tempered counterfeit, yeah worthless.
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Post by durinnmcfurren on Jul 30, 2021 23:44:33 GMT
In brief: when you cool down a really hot blade (or any object), you have a few problems.
1. The object can't be uniformly cooled, because the outside of the object will cool first.
2. Cooling puts major stresses on the blade, and the bigger the temperature differential between the inside and the outside of the blade, the bigger the stresses.
Therefore:
If you cool a blade in water, which will make the outside of the blade cold EXTREMELY fast, you will put the steel under more stress than if you cool it in oil, which will cool it more slowly.
Thus, if there are any structural weaknesses in the blade (either from your smithing errors, or from just plain bad luck with your choice of iron), water is much more likely to make your blade shatter.
And this is especially bad because at this point you have done most of the work to make the blade, so you really don't want to end up having to go back to the start!
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Post by Adventurer'sBlade on Jul 31, 2021 0:37:14 GMT
The benefits of oil as far as consistency and lower risk outweigh the faster quench of water for monotempered spring steel blades IMO.
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Post by Drunk Merchant on Jul 31, 2021 0:57:07 GMT
Those reasons guys, is why after water quenching a sword you make sure there is no hagire, otherwise it goes into the Oroshigane pile. For sure, oil is far superior in something that can be mass produced by semi skilled smiths. Which is why in war oil quenched Showato were made by the tons and honestly, they’re pretty good cutters, their impeccable oil treatment and shape makes them rank alongside other high end oil quenched. That said, any Japanese smith worth his salt makes sure the quenching hasn’t compromised his sword and uses strategies like having a milder steel for the kawagane which leads to utsuri and more flexibility. Remember, any good smith in the Edo Period would torture test his work with everything from pig cadavers to armor to beating it with wood to prove it wouldn’t be brittle. Yeah they stopped doing that at the end of the Shinto period but that so incensed smiths like Masahide that they then went into even more brutal torture tests, where smiths with too break prone swords lost feudal domains worth of clients with the orders being awarded to swords that would stand up to absolutely brutal abuse. Markus Sesko has a book on this, fun read:https://www.lulu.com/shop/markus-sesko/e-tameshigiri/ebook/product-21700689.html?page=1&pageSize=4 A lot of those wazamono standards carried over to the production RJT Star Gendai, and Mantetsu. And they made an impressively large amount of them. True water is harder but with skilled smiths and good tech, and effort, it wouldn’t be hard to produce superb water quenched modern steel swords like the Mantetsu. That said, while oil was great for mass producing, the weakened edge still is a detriment. Take this frightfully expensive L6 oil quenched, the smiths weren’t competent and gave it a bad oil quench that made its edge so rolling prone that the whole monouchi went and left from a blow far more mild than RJT tests. Not a rare thing either as members have complained of the sword breaking from the likes of tatami and gallon jugs and instead of upping standards, CAS says that’s normal for swords. Even oil quenched L6 without oil quenching failures seem to lose their edge at an accelerated rate. The Showato problem of accelerated wedge wear bit with a vengeance. Honestly, that makes me agree with the Japanese military, better to make water quenched who can take a beating and test them rigorously, so that in war if used, they’ll suffer bitty nicks (like my star gendai); than take an oiler that doesn’t have production problems but is liable to have the whole monouchi crumple the first time it hits bone. With the former, you still got as sword with polishable nicks, the later, your edge in your strike zone is gone. And obviously European swords can handle oil quenching just fine since they’re more robust and not as dependent on having a weird meticulously controlled rainbow of hardness to function as Japanese swords do. But yeah, at least as far as Japanese swords go, water quenched star and mantetsu handled WWII better than oil showato even though the later wasn’t badly made. That’s gotta count for something, right? And anyways, as far as money goes, water commands more than oil.
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pgandy
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Post by pgandy on Jul 31, 2021 2:10:40 GMT
Thank you for enlightening us. That is very informative information.
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Post by Adventurer'sBlade on Jul 31, 2021 2:39:50 GMT
I would bet that almost all of our resident smiths here use either some form of organic oil or a commercial quenchant like Parks 50. The quench would be heated warm to allow faster cooling and there may be multiple heats and quenches to get maximum grain transformation before tempering.
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