tempering blades old skool styles

[cheesemonger]

i hear alot of things thrown about like vikings wouldn't always clean the blood off their blades but 'cook' it in to give the iron extra strength - is this true?

any other interesting techniques blades have been strengthened throughout iron etc use?

would be interesting especially as i'm writing a fantasy in which dwarf fortress in particular has influenced alot of the detail within - any other cool tricks of the trades?

cheers in advance

 

[Merlkir]

As many other liquids used or mentioned as being used, blood isn't particularly good. You can use oil, piss (urine), I think I've heard about stabbing a body (although that sounds pretty stupid to me)...

Usually it's just water or some oil. Blood doesn't give any extra strength at all, it's a superstition and I don't think any real smith used it continuously. What matter is how quickly or slowly you cool the blade down and if you cool the whole thing, or if you cool the edge first and the spine and rest of the blade slowly after that. (which is possible by adding clay to the parts you want to cool slower)

 

[Urlik]

maybe some of the carbon in the blood is transferred to the blade making the edge harder 

if done, it was probably more of a psychological effect.

this sword has already tasted blood and is hungry for more

 

[Merlkir]

Does blood contain carbon though? It contains carbon dioxide, but so does air and mineral water.

 

[PineconeKing]

I KNOW! PUT THE SWORD IN AIR WHILE IN USE! {Looks completely innocent of the very stupid comment he just made}

 

[cheesemonger]

awesome so it's almost like tempering a wok. oil makes it tough as **** and gets a hold in the metal

 

[cheesemonger]

i'm all out of blood atm tho

 

[Night Ninja]

Oh boy. I'm not even sure where to begin.

awesome so it's almost like tempering a wok. oil makes it tough as **** and gets a hold in the metal

No, it isn't. Oil doesn't make it 'tough as ****' by soaking into the metal, that's the daftest thing I've ever heard.

The quenching medium mainly determines the rate at which the metal will cool. A badly done quench might cause some serious structural damage to the blade or muck up the microstructure of the steel. Attempting it with blood is a bad ****ing idea simply because the stuff will cook and coagulate on the blade.

 

[Urlik]

hey, I never said it was a good idea.

just that was the only possible thing I could think of that would have a possitive effect on the blade.

I think the other reason is  more likely (if they ever did do it)

 

[Farmind]

...any other interesting techniques blades have been strengthened throughout iron etc use?...

Today the proper heat treatment of carbon steel is well-known science, but previously it used to be a mythical art full of ridiculous beliefs. When the superstition is gone, the processes of annealing, hardening and tempering is pretty straightforward, and it is usually very easy to test if the process is working properly.

There are several traditional methods how quenching could be done (how to reach the proper temperature, how to quench the metal, what quenching medium should be used, etc.). Most of these traditions are complex and low-quality ways to complete a simple process.

For example, using "urine of red-haired man" as quenching medium has the same effect as quenching into brine. Salt crystals in urine or brine breaks up the steam-sheath, and increase the cooling effect. However, in some rare cases (when using over-carbon steel) it is possible that impurities in urine will migrate into the metal and cause problems.

 

[Soil]

Does blood contain carbon though? It contains carbon dioxide, but so does air and mineral water.

Well yes, it does, but not elemental carbon

 

[Night Ninja]

hey, I never said it was a good idea.

just that was the only possible thing I could think of that would have a possitive effect on the blade.

I think the other reason is  more likely (if they ever did do it)

Wasn't directed at you, Urlik.

Farmind, would it be wrong to say that higher carbon steels should generally be quenched in less efficient materials? It seems to me that cooling a very hard piece of tool steel in oil or water is going to lead to some major structural stresses.

 

[cheesemonger]

Oh boy. I'm not even sure where to begin.

awesome so it's almost like tempering a wok. oil makes it tough as **** and gets a hold in the metal

No, it isn't. Oil doesn't make it 'tough as ****' by soaking into the metal, that's the daftest thing I've ever heard.

The quenching medium mainly determines the rate at which the metal will cool. A badly done quench might cause some serious structural damage to the blade or muck up the microstructure of the steel. Attempting it with blood is a bad ******** idea simply because the stuff will cook and coagulate on the blade.

besides the bla bla me faceless smart answer forumboard bla - what do you mean by pointing out my daftness? explain if you could. with a wok, 'cooking in' the oil or just soaking in oil cold serves a great purpose - what that is is also above my daftness, but i believed doing this rather than soaking off the oil in something preserves a wok for much longer, true?


In this question, besides the reference to woks which has alot to do with heat, i was asking about restoring the quality of blades AFTER they've already been made and have been used.

What types of oils/substance/technique, besides keeping it sharp, have been used in order for it to maintain strength or avoid denting or bluntness?

if you have a blade with a bit of rust, what is done to avoid that or minimize more? or if it gets really bent (perhaps not enuf to leave a kink, but enuf to bend like a U then spring back into form) and becomes less sound in structure, or just seems to have more bend than before?

 

[Sushiman70]

How can you compare the use of a cooking utensil to the forging of a sword?

 

[Night Ninja]

Toughness doesn't equate to rust resistance. Oil protects metal from rust by forming a protective layer over the metal, it doesn't permeate into the metal by some magical effect.

A blade will get blunter with use, that's pretty much taken for granted. To avoid damaging your blade, don't abuse it by using it on objects that it wasn't intended for. For example, chopping wood with a sword is a pretty stupid thing to do. Even a first-rate blade will be damaged if you use it for inappropriate tasks. If a blade is already pretty heavily damaged e.g. massive set, giant nick that cannot be ground out or a catastrophic break or crack, your character's best bet is to reforge the thing. Attempting a bodge job like the elves did with Anduril in the LotR movie trilogy only leads to tears. AFAIK retempering it might correct a set, though I'm not sure on that.

If you have a blade with a bit of rust, polish it out. If you want to minimize rust, wipe off the blade after use and keep it in an environment with minimal moisture. Ensuring that your blade is completely dry before oiling helps too, otherwise it's quite pointless.

 

[cheesemonger]

okay smart arse 'what a dumb question' remarks included thanks for your answers. besides my story, in which i am basing in an age in which various conditional factors lead to vastly different levels of intelligence and ability, therefore i have much room to play with ignorance and awareness, i actually have an old mate with an old iron blade which is rusty and has alot of bend to it. So to know that to file off the rust and dry it out and then oil it is excellent as restoring it for him is always re-inspired when i see something like it in m&b etc.
-
but i do say in a fictional creation, the idea of blood left to congeal and permeate the iron giving it extra strength and metal may be bull**** but it does sound cool. 
i guess reforging the blade is always a given, i was more interested in recovering strength in a blade that has seen better days or alot of fighting and weather (especially considering making a new blade may not always be an option, so preserving one using basic commodities is a topic of interest)

 

[Night Ninja]

Well, see, if you'd done five minutes of research on Google before coming onto a forum and asking people to do your work for you, you'd have found out that the very idea of using blood or a living person to temper a blade is pretty damned stupid.

It's not 'cool', it just betrays a massive amount of superstition and general lack of metallurgical knowledge. I'm betting that it wasn't a smith who came up with that, it was either some idiot skald or an obsessive Viking nuthumper.

I don't think there's really a way of 'resetting' the properties of a heavily-used sword. A sword will get dinged up as you use it, and there'll come a point where you will have to replace it or risk it failing you at a critical moment. Just treat it as a tool and don't get too sentimentally attached to it. Of course, if it's a fictional world, there's always magic.

 

[Merlkir]

Yeah, just make the sword magically drink blood and use its life force or some bull**** like that, it'll be much more believable than tempering swords in it.

 

[Kissaki]

Ironically, blood is just about the worst thing you can get on your blade, unless stains and rust is your thing. There is nothing you can do with blood which makes it beneficial for steel. Same goes for vegetables, really: unless you are using stainless utensils (which swords are not), clean off your blade immediately after cutting vegetables, or it is going to stain like crazy.

 

[Farmind]

... would it be wrong to say that higher carbon steels should generally be quenched in less efficient materials?...

The blade may warp and edges may crack if the metal has not been normalized before quenching.  Heating the metal too hot may also cause edge cracking. The proper cooling rate depends on the steel, and the rule-of-thumb is:

Low carbon steel is quenched in brine.
Medium carbon steel is quenched in plain water.
High carbon steel is quenched on oil.

I use high carbon steel for making blades, so I use oil quench. I have a a capped metal pipe filled with quenching oil, and the pipe is placed upright in a hole in floor at my smithy. I usually make a hole or a loop in the blade tang so that I can hang the blade from a wire. When the blade is ready for quenching, I drop the blade into the oil-filled pipe. The wire prevents the blade from hitting the pipe end-cap, and allow me to pull the blade away from the pipe.

The oil starts to burn when the blade enters the pipe, so I just cover the pipe with a metal lid so the fire is extinguished.