A myriad of questions!

samuraistuart

samuraistuart

Joined
Dec 21, 2006
Messages
3,158
Guys, I've been "surfing" the knifemaking forums, soaking in knowledge like a sponge. Many people are willing to part with their knowledge, and for that I am really greatful. Sometimes topics get heated, and I'm learning that having an opinion on a certain quenchant is like having an opinion on politics or religion....most people don't want to hear it. So, with that said, I'm not trying to open a can of worms here. I would like to know what ya'll would consider the best course of action in my situation. I have mentioned this in a previous thread, (maybe at a different forum?) but I have a few more questions.

I'm new to the hobby. Stock removal only. Hacksaw, files, sandpaper. Working on knife 3. I've been using 1080 and 1084, canola oil......great results. I bought some W-2, because as a newbee I just HAD to have it, you know? Just HAD to have it. Problem....it's a full quarter inch thick (4'x2"x.25"). Really TOO thick for hunter/skinner type knives. I'm enjoying my .110" 1080+ right now! But I'm contemplating, "What am I going to do with my coveted bar of W-2?" I wanted the W-2 for the vanadium and to do a hamon (although the 1080 series produce nice hamons themselves).

1. What kind of a knife would you make out of .25" thick W-2? Or would you? Can I try my hand at pounding steel, and hammer a section to say 3/16"? Would that be feesible to you guys? I don't have a forge, will an open fire with a great air source get that hot? It should, right? I shouldn't have bought it, but I did, and now I have it. Maybe it's not worth messing with, until I get a forge (and forging skills!).

2. Here it goes....what quenchant would you use? I don't have Parks 50. Would like to not have to spend the money on it. Will I get "good enough" results with 130 degree canola, or brine? It will be 1/4" at the ricasso, or 3/16" if I can thin it.

Thanks in advance!
 
el0147 said:
For info on the quenchent, check out this thread going on, the same question was asked allready today.

http://www.bladeforums.com/forums/showthread.php/1032626-brines-for-quenching

With 1/4 w2 I think I would make some Tantos.
Click to expand...

I thought of making a few tantos. I love 'em. I have one of Cold Steel's tanto's (the San Mai with small tsuba), and it's only 3/16". So is the Pendelton hunter, which is a much smaller knife. But a full quarter inch?......my Tiger katana, my Cold Steel katana, and my Shinto katana are quarter inch. I'm thinking blade geometry, and what blades have .25" spines (at the ricasso/tang). I thought of making a katana, but it would be short one....maybe waki. I actually thought of doing a ninja-to, to be honest with you! I was thinking of maybe a bush craft type knife, but personally, 3/16" would be more ideal (to me) for that kind of knife.

How about another question, if ya'll don't mind? I'm just awe struck with what happens to a katana during quench. A blade that is forged straight will develop a curve when it is clayed and quenched, right? Due to the different cooling rates of the edge/spine. How does one differentially harden a ninja-to, and have it come out from the quench straight? Forge it bent in the opposite direction? Or is it the relatively short length of a ninja-to that keeps the blade straight? Maybe the forger will "straighten" it immediately afterwards, if a sori is imparted to the blade. I have NO idea. Oh, wait...yes I do..........quenchant medium, right? Oil won't impart a sori, while water will? I very well could be wrong on that one, too!
 
I have written long threads on why sori develops, but the short answer is that it has to do with the size of the structures that form, not to cooling rates.

If you want a straight spine sword, there are several ways to get one.
1) forge in a reverse sori and leave extra at the spine to grind it straight after quench during shitaji togi. ( simplest method)
2) use a steel that won't develop sori ( low or no hamon - 5160 is a good choice)
3) use a quenchant that won't develop sori - oil. ( lower hamon activity)
4) remove the sori after quench. This is hard to do, but can be done with skill. (Not a good choice)
5) don't do yaki-ire ( forget the hamon and make a 5160 sword)

Here is the text of an older post on sori:
The sori develops as a result of the blade ending with two different steel structures.
Brine or Water is the usual quenchant because of its speed (fast oil will also work).
When the clay coated blade is brought to critical temperature all the steel is austentite.Upon the first quench ( usually about 3-5 seconds) the blade will bend down-wards.This is because the edge (uncovered by the clay) converts rapidly to martensite,contracting as it does (under the clay it is still austentite).After a few seconds out of the quenchant,the blade is plunged back in to allow the area under the clay to cool and harden.It cools slower (missing the martensite nose on the curve) and ends up as pearlite.Pearlite contracts much more than the martensite does,and thus makes the blade suddenly curve up-wards.
If all goes well,a straight blade (before quench) will end up with a nice little sori.The area where the pearlite meets the martensite ends up as troosite ( old name for martensite/pearlite mix),which creates the hamon.
If all does not go well there is a sharp PING!!! and half the blade falls into the bottom of the quench trough.

So, a straight blade will end up with a slight sori.A blade with a down-ward curve will end up straight.And a blade with a little up-ward curve will end up with a tachi size sori.The end result is a product of a bit of luck and a whole lot of skill in forging. At best the smith can only guess a range of expected sori.

Experience and consistency are the best way to learn this subject.This is the reason Japanese smiths try not change their steel in any way at all,so they can get repeatable results.A particular school (forge) will use the same source for centuries if they can.Many of the "legend and Lore" things about sword smiths are because they are shooting for repeatable success.It may not actually matter if the blade is quenched pointing true north,but if you do it that way EVERY TIME you will have ruled out one possible variable. Eventually, the smelting,forging and quenching become ceremonial (almost to a point of mystical fanaticism sometimes),and then the Smith can expect consistent results.It is easy for a new maker to assume that if you do what Masamune did,you will get the same result.That would only be so if you were doing it with Masamune's tools, steel, forge, and did everything exactly the same as he did.(And you still wouldn't get a Masamune grade blade without many,many years of practice.)

As a final comment,this same practice is what makes one maker a legend and another frustrated.
Mete may use assayed steel,High tech ovens with argon injectors,and salt pots to get the most from the metal.Mark Williams may use junk yard steel,bless his forge area with chicken blood before starting to forge,heat the blade with a torch,and quench buck naked,facing north,at midnight,in a vat of bear grease .Both make outstanding knives,it is not the difference in method that you should see here.It is the fact that they ALWAYS do it the same way.
Learn what works well for YOU,practice it regularly,repeat successful attempts until they are the expected norm.Jumping around a lot in technique and materials will only confuse you.
Stacy
 
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Another option would be sell the bar to me :) or since you're right down I-35 from me come to my shop and ill show you what to do with it.
 
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