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quenching 1095


ryanwrath
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So i have a question about quenching 1095...my only quench setup is in a vertical 5' tube filled with oil ............if i am claying a blade and trying for hamon, will i get some good results? or with clayed blade should i still edge quench?

 

thanks.

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with a clayed blade, you should do a full quench, vertical or horizontal doesn't really matter, except perhaps in the case of long blades, where the time differential between quenching the tip and quenching the forte could cause a problem.

 

some things to bear in mind:

 

firstly, quenching in oil will cause the blade to curve downwards to a degree. what degree depends on a number of factors.

 

second, well normalised, there can be problems getting any depth of hardening on 1095 in oil, unless you have a very fast oil. to counteract this, i usually do a few things:

 

1. grind almost to a finished cross section, which will increase the width of the hamon you can acheive.

 

2. pre-heat your oil, though i suspect you already do that.

 

3. bump up the heat a little, 50 - 100f, above critical before you quench, this speeds the quench slightly, and eliminates the problem of the blade starting to transform before you get to the quench. so long as you don't have any soak time at the higher temp, you should have minimal grain growth with 1095, though you will want to soak for a while right at critical, if possible, before bringing it up hotter to ensure complete transformation.

 

good luck

Jake Cleland - Skye Knives

www.knifemaker.co.uk

"We can't solve problems by using the same kind of thinking we used when we created them."

"Everything should be made as simple as possible, but not simpler."

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."

 

Albert Einstein

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I quench 1095 in warm brine, so this may not apply to oil quenching, but I've found that it is important to make sure your blade has no "stress risers" before quenching. I smooth everything lengthwise on the blade itself, putting a very slight radius on each side of the spine, and making sure the edge has a slight radius on both sides. Back in the tang area, even though I rarely quench any part of the tang, I still make sure there are no sharp corners; everything gets radiused, even if it's so small you can barely see it. This is especially important at the "step" area on a hidden tang, but I also knock off any sharp corners on a full tang as well. It doesn't take much; just enough to knock off the sharp edges.

 

It's cheap insurance, especially when quenching in brine or water. Any sharp edge, or corner is a potential stress-riser; and during the quench, the steel is going through enough stress as it is, without making things worse. I lost several blades when I first started, due to cracks brought on by stress-risers.

To realize that you do not understand is a virtue; Not to realize that you do not understand is a defect.

-Lao Tzu

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thanks for the info. i had forgotten about the dive it takes in oil. it sounds like i would want to go with water maybe. I also have one more question i remember reading in posts someone adding soap to their quench. is that in addition to salt? does it soften the blow so to speak of the quench? i was curious what role that played. thanks again.

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does it soften the blow so to speak of the quench?

I haven't tried it myself, but I have read about adding dish soap, and/or borax to the brine, or to plain, warm water. I think the intention is to help break the sheath of steam surrounding the blade and actually make it quench faster, not slower.

To realize that you do not understand is a virtue; Not to realize that you do not understand is a defect.

-Lao Tzu

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both soap and salt help disrupt the vapour phase of the quench, as Sean says, but they may also help even out inequal heat extraction, hopefully making the quench a little less violent. plain water is a relatively slow quench for about the first second, until the vapour jacket collapses, so salt and/or soap will help with extremely low hardenability steel, but i don't think it's necessary for 1095. the main danger with a water quench is from the very fast heat extraction in the nucleate boiling and convection phases. once you've beaten the pearlite nose and got to the martensite start point i don't think a fast quench is desirable here in terms of hamon production, but it is still necessary for producing lots of sori.

 

it would help to know what size and style of blade you are making, but assuming you want to keep your blade shape pretty much the same as it was pre-quench, and still produce a nice hamon, i'd normalise 3x at descending temps, clay up, soak right at critical for a minute or so, quench for a count of 3 into plain hot water, and then finish the quench in oil. starting the quench in water, i wouldn't take the blade any thinner than 2mm on the edge, and i usually go closer to 3mm. the thicker the edge is, the smaller the chance of cracking, and the greater the difference between spine and edge, the more sori you'll get.

Jake Cleland - Skye Knives

www.knifemaker.co.uk

"We can't solve problems by using the same kind of thinking we used when we created them."

"Everything should be made as simple as possible, but not simpler."

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."

 

Albert Einstein

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