the hardening line

T

twynn5586

Joined
Aug 21, 2002
Messages
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I haven't been bladesmithing for long but i have a quick question about hardening lines. How do i get the line to look wavy and irregular?
 
Drink a lot of vodka the day before so as to induce a good case of the shakes.

RL

I don't know how you do it.
 
Coat the spine of the blade with refractory cement and "paint" it down the sides of the blade in the pattern you want. Let the cement dry thoroughly and then edge quench the blade.

If you look here in the shop talk section you should find info on hand rubbing the blade to best show the temper line.
 
Xrayed,
You got it all wrong, Rlinger hit the nail on the head. :cool: ha ha ha

-Jason
 
Once the blade has been coated with refractory cement or fire clay, fully quench it. An edge quench is not necessary (the cement prevents the back from hardening), and may be detrimental to the desired hardening line.

John
 
John is right....I forgot to mention that whenever I do this I quench edge first but the whole blade goes in at once.
 
I thought Greg probably meant quench edge first--as opposed to tip first--but I just wanted to clarify it for those not familiar with the technique.

John
 
And do it in water.

Water is an extremely violent quench, causing very severe stresses in the blade...but it will trap your line in a very wild and beautiful variance.

You can get really nice lines in oil, but all of my best and the best I've seen by others were done with a water quench.

The blade has to be tempered RIGHT after a water quench...even standing there for a minute to look at the blade will often result in a crack.

So when you're ready for high drama...both in the shop and in your hamon, do it in water. For now stick with oil :)

Nick
 
Mr. Wheeler. Is there anything you do to the water to help reduce the cracking? I had heard you should put enough salt into the water to make an egg float. Is this a brine quench? Will it do as well as "strait" water? Also what temperature does the water need to be at? I gave up on water because I was cracking to many blades. After this thread I just may try it again!:D
 
I heat my oil to approx. 140 - 145 F. to lesson thermal shock. If I were to do a water quench I would, unless advised by those who know better, do the same but a few degress lower since water will steam at the plunge causing a barrier between steel and quench. Though, I have not yet tryed a water quench.

RL
 
RL is right, the vapor jacket that is created with a water quench can cause problems.

Putting that much salt in the water raises its boiling point and allows you to get the water hotter than without. This is indeed a brine quench.

This gets back into the cool factor of salt quenches...a lower viscosity than water (so it's "wetter" than water) and no vapor jacket.

I personally have had the best luck with straight water with some liquid soap in it to help break the surface tension of the water. I have tried different temps, and although I can't explain why, I've had the best luck with the water at 75 degrees or so. Again, I'm not sure why, that's just what's worked here. Most likely I just happened to hold my mouth just right at the same time the water was at 75...:o I think a big factor in water hardening a blade is getting it in the lower end of the critical temp range...at least that's how it seems to me.

I forgot to mention that I would only recommend starting with water quenching steels like 1050-1070, 1095, W-1, etc. You can get all those hard in oil (usually) but you can get more drama with water.

1050 is pretty forgiving in water...but it's much better suited to swords than knives (IMHO)

I have played with all kinds of clay coating, and the latest one for me is Satanite. My friend Joss gave me some, and it seems to work very nicely. You can make a very dilluted mix and "wash" it over the blade, and then make a thick mix of it for a heavier coating of lines and spine coating.

Creating a dramatic hamon is an art. I am only begginning to understand it, and it's fascinating to me. I had the fortune to handle some Japanese swords owned by Grandmaster Swordsman Sung Beck, and the hamons in them were absolutely jaw dropping (as was the entirety of the pieces).

Sorry for rambling :footinmou

Nick
 
Just as a note, there are quenching oils that are very close to water in quench speed that greatly reduce the chances of overstressing or cracking the blade. I have been told by many a bladesmith that "the only thing water is used for in my shop is for drinking."
 
Parks Metallurgical makes a couple of different, high quality quenching oils. I can't remember which one is for oil and which one is for water hardening steels though. I think the water hardening(faster) oil is called #50. The other Parks quenching oil that I can remember is called AAA. I may have them mixed up, but one is for water hardening steels and the other is for oil hardening steels.
 
twynn5586,
I only use water. Brine (salt water) quenches are faster than pure water because the salt precipitates out and causes the outer surface of the steel to explode off the part. Those explosions are what disrupt the film of vapor in the water and remove it rapidly. Essentially getting more "un-vaporized" water to the hot steel. I have never had a need for brine, but thats just me.
I quench in water between 145-155°F. I forge 1045. Gotten similar results with 1050 as well in the past. The whole blade goes in at the same time and I temper for two hours within about 2 minutes from quench usually, max. I also use satanite.
I have felt the wrath of yaki-ire many, many times and it has only been from my failures at it, have I truly learned a damn thing.

-Jason
 
Thank you Mr. Whee... er, I mean Nick!:D

Keep on "rambling" Nick because it's verry informitive.
My thanks again. Jason, thank you as well. This is all great info.
 
Well, I get my Satanite from K&G in Lakeside, AZ. (520)537-8877 Don't know if they are the cheapest but, their prices are reasonable enough for me to keep buying. They also refer to it as "floor refractory" for lining forges.
 
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