Blowtorch hamon-real or fake? [sword talk]

[@vumanhtung]

*Fun fact:* this video is by far the only one talking about hamon in detail. Love it.

[@zulfikar3440]

Thank you for the lesson and information... awesome.

[@IvanIvanov-pj9hv]

Its like a modern way hamon or something like that

[@Ho0331]

What a fascinating practice, I hadn’t heard of this either! Thank you for teaching me something today, keep up the good work!

[@JustaBug]

Thanks for the support!

[@daniellopezeverest]

Thank you for sharing this awesome and informative video! :-) my favorite part was when you said that if they warp the sword for doing it wrong now you get a banana

[@JustaBug]

You're welcome. Thanks for the support!

[@johnflorio2351]

As a beginner Smith I've seen this many times. A differential hardening is all that is being done. With clay there is more control and therefore can be much more beautiful when finished. Without you tend to get a simple straight lined homone. Every bit as effective, not nearly as pretty or intricate.

[@1810jeff]

Would it actually be as effective though since you need to let the steel soak so that the carbon gets distributed evenly for the quench.

[@johnflorio2351]

@@1810jeff the carbon is already in the steel. Soaking will make carbon leave the blade unless it is immersed in carbon. A process called carburization. Heat treatment is like freezing water, do it one speed and you get lots of bubbles another speed is clear as glass even though the water had the same amount of o2 to begin with. O2 being carbon in this metaphor the ice being the iron crystals.

[@1810jeff]

@@johnflorio2351 Then why is soaking considered to be an important part of heat treatment. Also decarburization shouldn't be a problem at 1500f since it starts happening at around 1200f and only starts ramping up once it gets past 2000f.

[@johnflorio2351]

Soaking ensures an even heat throughout, and therefore grain growth. But differential hardening denotes different temperatures in different places. Weather one gets hot all the way and only the edge is cooled quickly or just the edge is heated to critical temp and the whole blade is cooled at one speed. The effect is very similar, maybe not the same, but very close. A good rule of thumb in blade smithing is don't heat your steel any hotter or longer than necessary for your process.

[@LucianoSilvaOficial]

Hard to say anything about the result of the blowtorch tecnich. But its similar to how axles are heat treated, using blowtorches and water spray to increase the hardness on the surface while retaining the core soft. Probably it can work if done under the right conditions. But there are very good blades that had gone under quenching and tempering that can have better phisical properties than traditional quenched blades. I prefer to have a good blade with no hamon than a piece of junk with good aestetics.

[@michaelrs8010]

Greetings from Orange County, California. I'm new to the whole Japanese sword thing and so obviously looking through a gazillion KZbin videos on this, that and the other thing. Just wanted to say that I like the way you throw the science into some of your videos. Also, I'm kind of an end results guy. To me it makes no difference if a guy spends 100 hours hammering on steel to turn it into a blade or if a machine does it in 10 minutes...as long as the quality of the end product is the same. Same would be for this type tempering method...IF the end result was the same. But you explained it pretty well as to why it's not likely to be.

[@JustaBug]

Thanks for the support and welcome to the channel. Definitely agree with the end result approach to practical use blades. Plenty of mass produced blades that are decent enough to use as training swords if you're not looking for a work of art

[@iDTecKt]

Informative video as ive not come across this before and ive been studying Katanas, thanks, ive seen some really nice swords i want to buy but then i find out there wired Hamon, ive not seen them in person but from what ive seen on film im not impressed now i know the difference, the only part of your video i dont agree with is that you say they look real, because you can only see real hamon in certain lighting, similar to acid but ive read that looks better than wired, how much do you have to spend to get a real Hamon edge?

[@JustaBug]

Blowtorch hamon looks real. It is different from a wired hamon. Metallurgy wise its the same compounds being formed. For a real Hamon it's usually in the $250 kind of range

[@ppvita2853]

Is there still swords being made in the more traditional way? Have your swords made in a traditional way?

[@JustaBug]

There certainly are swords still made the traditional way. My wakizashis are made with traditional clay tempering

[@marcuslee3090]

Great information blow torch is good but it’s only 45 percent of the clay tempered halons Benifit

[@Neechan0077]

How did you get 45%?? Are you a smith or have any expertise in metallurgy? Bro don't make up rubbish

[@1810jeff]

@@Neechan0077 It's actually not even that high, when you heat treat steel you have to let it "soak" meaning you leaving it at around 1500f for a certain amount of time which varies depending on the steel and since he wasn't doing that it likely wouldn't harden evenly. You can do hamons without clay but they require a fast cooling steel like fast quenching tool steel and proper blade geometry so that the edge cools way faster than the spine. There's also another method that creates something similar to a hamon this being a quench line which is done by only quenching th edge of the blade bit this usually results in a straight line so it's not really worth doing unless you have a steel that doesn't like hamons like 1084 or any other high manganese steel.