Water or Oil quenching

bladsmth said:
Chris is a great guy. He is also a rare talent. He started with Japanese blades, and has done well ( I prize the one he made for me). I helped him in some of his early projects, but mostly he just needed materials, tools, and info. He has a natural ability to do bladesmithing.

However, few....make that very few....make that almost no..... new makers will have anywhere the success to start with that Chris had.

I will check with Chris, and if he vouches for you, my library is at your use. Also, since you have someone who I respect as your mentor, if you need help in learning, or materials, I will see what I can do to provide them for you. A visit to my humble shop could also be arranged after the holidays. I have all of Walter Sorrell's' DVD's on making katana and doing hamons, etc.. There are many more books and DVD's I will loan you as you progress.

Take care, hope to hear more from you.
Stacy
Click to expand...

Wow! Thanks a lot! It all thanks to Chris that I even got into bladesmithing. He is quite a blessed craftsman. I am very lucky for his help.

Thank you for your generosity Mr. Stacy, and I would love to make a visit sometime after the holidays.

Thanks Mr. Burke for the info, exactly what I was looking for.
 
Bill Burke said:
Just regular house hold salt NON iodized. be careful nnot to over heat the blades and you should have too many problems.
Click to expand...


+1 for what Bill said about not overheating. Be SURE you know the steel is at the right temperature when you quench.

I use rock salt AKA de-icing salt from the farm store.
 
K R Johnson said:
... allowing the water to "wet" the surface uniformly, so it seems to be faster. It isn't. More salt will slow down the quench. As has been said, plain water forms steam or gas pockets which slows down the quench in some places and causes uneven hardening and takes longer to cool the steel in the pockets.
Click to expand...

This isn't accurate information. As per Totten's Handbook of Quenchants and Quenching Technology:

"Cooling rates are higher than those of water for a given degree of agitation, or, alternately, less agitation is needed to get a given cooling rate. Higher cooling rates reduce the possibility of stem, the cause of soft spots in quenching, but higher cooling rates generally increase the likelihood of distortion and cracking."
"In quenching, minute salt crystals are deposited on the surfaces of workpieces. Localized high temperatures cause crystals to fragment violently, creating turbulence that destroys the vapor phase, resulting in very high cooling rates."
 
i know people r debating oil vs. water quench but i feel like i have heard some putting a layer of oil on top of water and quenching.....what would that do?.....just curious....ryan
 
Ryan, my understanding of the practice is that the oil will lessen the shock to the steel as it enters the quench. You just have to get all the way below the oil layer in a continuous, smooth motion with your blade to have even cooling. The oil starts the cooling process in a more controlled method and the water accelerates it to pass through the critical pearlite formation stage fast enough.

--nathan
 
Re: oil on water

I've heard of this, but I haven't experimented with it. But just intuitively it seems backwards to me. Don't you want a fast cooling rate at first, then slower as you get under the nose? I don't know...
 
I hear you, Nathan. My thoughts on it (without ever trying it) are that you have a window of time that you can have a slower cooling rate before you enter that critical realm of pearlite and bainite formation. So you have your steel at around 1500F when it hits the water (or water with oil on it). You have that 400-500 or so degrees that you can have a slower cooling rate before the critical cooling happens from around 1000F to around 500F. You have to get through the 1000-500 range quickly, and then what happens once martensite begins to form can again be slower (as with an interrupted or marquench with cooling in air).

--nathan
 
The I-T diagram for 1095 shows less than one second to get down below 1000 degrees to get pure Martensite(very difficult). When you get past the nose of the curve then you can slow the cooling process( interrupted quench).
 
bladsmth said:
I can also tell you that starting with Japanese blades and water quenches is not the easiest way to get into knife making. That said, Wally Hayes' videos are superb.

Stacy
Click to expand...

I agree HIGHLY on this, get Wally's video KATANA, you will be able to do one, or atleast a reasonable facsimile to a traditional katana, but much of the information in the video can be adapted to go a more traditional route.
 
Matthew Gregory said:
This isn't accurate information. As per Totten's Handbook of Quenchants and Quenching Technology:

"Cooling rates are higher than those of water for a given degree of agitation, or, alternately, less agitation is needed to get a given cooling rate. Higher cooling rates reduce the possibility of stem, the cause of soft spots in quenching, but higher cooling rates generally increase the likelihood of distortion and cracking."
"In quenching, minute salt crystals are deposited on the surfaces of workpieces. Localized high temperatures cause crystals to fragment violently, creating turbulence that destroys the vapor phase, resulting in very high cooling rates."
Click to expand...

I'm quoting from the book "Tool Steel Simplified" by Frank R. Palmer and George V. Luerssen and published by the Carpenter Steel Co.

This is scanned from page 252:

Brine-1.jpg

And page 254:

Brine001-1.jpg
 
thats seems a bit counter intuitive. Wouldn't a more dence liquid (brine) be a faster heat sinc/absorb heat faster?
 
Mine was quoted from page 84 of "The Heat Treater's Guide: Practices and Procedures for Irons and Steels" 2nd Edition, referencing Totten's Handbook.

The end result is a more consistent, as well as more effective transfer of thermal energy with no 'hot spotting' due to the insulate effect of the vapor jacket. I suppose it's semantic, with both men seeming to say similar things, however rapidity of quench seems to me to be part and parcel with effective dissipation of heat. As 5-10% NaCl seems to fall under the territory of 'effective hardening', I submit that we are safely NOT discussing the 'over-saturated' effects of brine, and are not dramatically reducing the effectiveness of the quenchant.

After reading both my own quote and your sites above, it appears to be semantic, and misinterpretation of your initial post on my behalf.
 
SShepherd said:
thats seems a bit counter intuitive. Wouldn't a more dence liquid (brine) be a faster heat sinc/absorb heat faster?
Click to expand...

Kind of like oil, when you warm it up (to a point, 130F-140F max) you also thin it and it becomes a faster quench. Thicker fluids move slower and thus hold heat close to the blade longer.
 
Nathan the Machinist said:
Re: oil on water

I've heard of this, but I haven't experimented with it. But just intuitively it seems backwards to me. Don't you want a fast cooling rate at first, then slower as you get under the nose? I don't know...
Click to expand...
I use this process at times.(Actually any time I quench with water.) I just float about 1/4 inch of parks on top of the water.
Let me start by saying "I am not a metallurgist by any sense of the word." I just know it helped to reduce blade cracking. On most blades I use Parks #50. I mostly use 1095 and W2. These are the things that I have found threw cracking many blades.#1- Temp is critical I hold 1095 at 1525 deg.F for 5 mins and go straight to quench. If useing a brine I heat it to 80deg F. Oil at 100-120F temp.#2- Blade prep is also important finish to 400 grit before Quench with all sanding lines running from handle to tip that includes the edges. It also helps to wear your lucky water quench underwear. I don't know why this works I just know it works for me
If you are interested I will be doing a hands on demo at the next meeting of the North Carolina Custom Knifemakers Guild on Jan 16th. You and all are welcome to attend. It's in Troy NC.
Listen to Chris, his work is great.
 
69_knives said:
Kind of like oil, when you warm it up (to a point, 130F-140F max) you also thin it and it becomes a faster quench. Thicker fluids move slower and thus hold heat close to the blade longer.
Click to expand...

so, are you saying that if you heat water, the quench is faster?
 
having a thin coating of clay on the part of the blade to be hardened is said to help dispurse the vapor barrier formed by fresh water also. I have nothing to help substantiate this though it is just something I have read a few times. It does kind of make sense though. Don't it?
 
You must log in or register to reply here.
Back
Top