I had one of those days where I ended up spending far longer watching videos about a topic I never knew I'd be interested in. Today's topic: the famous Viking sword...the Ulfbehrt!
Basically, I saw this gif on reddit, and just really needed to know what part of the sword making process would need the blade to be on fire like that--apparently, it's called quenching, but I wanted to know more.
If you just want to see the gif section, it runs from 46:04 to 46:40 in the video above, but I somehow ended up watching the whole thing (and this wasn't exactly the most thrilling documentary...)
BUT! I was able to learn why it looked so badass in the original gif: we're seeing the smith cool down the sword very, very quickly in an oil-bath to harden the steel. Oil baths are heated to a higher temperature than water, which means the blade can cool slower at first. Different quenchants (apparently that is what you call the liquid used to cool blades during the quenching in) are used for different steels to impart specific internal structures that make the steel hard and flexible.
Sadly, I don't think they usually pull the sword out of the oil early and let it flame like this (for safety reasons). Blades shouldn't be removed from the quenchant (lol this work just kills me every time) until they are below the flash point of the oil. Still, I'm glad they did for the video because it's pretty cool!!
I honestly don't know why I'm writing this card but I thought it was pretty cool and you might too so hey hi hello if you're into this kind of stuff come hang out in the comments XD