Recommendation? Hybrid Quenching... Water, then Oil?

[Jesse WW]

Hello,

Iv done enough water quenching to know how badly it can go wrong, and have since moved onto canola oil which does a pretty good job in terms of establishing hardness and subtle hamon activity.

Since i don't have access or the budget to buy more professional quenching mediums, like parks, I'm looking for ways to establish better hamon activity.

I figure that i may be able to get better activity if i do a kind of water/oil hybrid quench... so quenching in water for a second, then plunging the blade into oil in order to prevent shocking the steel (too badly).

Will this do the trick? I just want to know what peoples thoughts are on this as iv never seen this quenching technique discussed before.

My line of reasoning is that the water will harden the surface of the blade quick enough to establish a hamon, then plunging it in oil to allow the innards of the blade to cool at a slower rate.

What are my chances that I crack the thing? The blade is 5mm (13/64) thick and iv shaved it down so the edge will be around 2mm (5/64). What temp should i preheat the water too? For this quench i will be using 1075. I also figure that since the clay has been applied to the middle of the knife as perpendicular strips as opposed to across the spine, no curving (sori) will happen, in turn preventing possible cracking?

Appreciate any responses

Jesse

 

[Steve Beckwith]

I have often wondered if you couldn't float 6" of oil on top of water in a cylinder and use that as a quench. The blade passes through the oil and then into the water in one motion.

 

[john april]

i have thought of that same thing steve, if it goes through the oil before the water, it will not receive as much as a shock from just doing water. curious what others think.

 

[Jesse WW]

Yep, have wondered about the same thing myself.
But the blade receiving the oil first would seem counterintuitive I would think? Why have the slow quench go before the fast one? Shouldn’t it be the other way around? So the surface of the steel receives faster cooling followed by the internal part cooling slower?

 

[Willie71]

3 seconds in brine, then into the oil. Great hamon activity this way.

 

[Daniel Fairly Knives]

I do both all brine and brine interrupted to canola. I'm using a light clay slip (heavily diluted satanite, water thin) before I apply my hamon clay and am having good luck. I think this is the key along with temp control. My edges are about .040" or maybe a bit thinner before quench so on the thicker side. I have not had a crack since i started using the first coating and I am going straight into a brine quench. I do an interrupted quench with only a split second or so out of the brine a time or two. (or into Canola for a bit after the water) I'm getting nice activity too, way better than I did with just canola or 11 second oil... also better than any combo with any other furnace cement. I find that i will do a few knives and usually go to straight brine only after getting a feel of quenching, the sound and vibration the knife makes is very subtle but can tell you when it is about to crack. I broke a lot of knives to get where I am now.

 

[Jesse WW]

3 seconds in brine, then into the oil. Great hamon activity this way.

Great to know! Looking forward to trying this with my next set of blades. Do you heat the brine beforehand?

 

[Willie71]

3 seconds in brine, then into the oil. Great hamon activity this way.

Great to know! Looking forward to trying this with my next set of blades. Do you heat the brine beforehand?

Room temp is fine.

 

[john april]

jesse i have heard about blades cracking from the stress of water quenching, so i thought a moment in oil would reduce the shock before hitting the water. i am searching for activity, so i am going to give the brine then oil a try.

 

[Willie71]

I do both all brine and brine interrupted to canola. I'm using a light clay slip (heavily diluted satanite, water thin) before I apply my hamon clay and am having good luck. I think this is the key along with temp control. My edges are about .040" or maybe a bit thinner before quench so on the thicker side. I have not had a crack since i started using the first coating and I am going straight into a brine quench. I do an interrupted quench with only a split second or so out of the brine a time or two. (or into Canola for a bit after the water) I'm getting nice activity too, way better than I did with just canola or 11 second oil... also better than any combo with any other furnace cement. I find that i will do a few knives and usually go to straight brine only after getting a feel of quenching, the sound and vibration the knife makes is very subtle but can tell you when it is about to crack. I broke a lot of knives to get where I am now.

It’s important to feel what is happening through the tongs. Feeling the vapor jacket collapse plus one second is really what I do, which is about 3seconds. It varies from blade to blade a bit.

 

[Willie71]

jesse i have heard about blades cracking from the stress of water quenching, so i thought a moment in oil would reduce the shock before hitting the water. i am searching for activity, so i am going to give the brine then oil a try.

It’s the second half of the transformation that cracks the blade. Water/brine is faster in the second half of the quench than the engineered oils. This is why brine gives you a sori, and oil gives a negative sori.

 

[Kentucky]

Walter Sorrels does it all the time. I've done it a few times without problem

 

[Josh Rider]

You can get really good activity with parks #50 with a much lower chance of cracking a blade.

 

[mete]

We had a customer [non-knife project] that picked the wrong steel . We told him we could probably save some parts. It was a water then oil quench .Customer was able to save most of them. Thing is that there's a lot of guessing before you get the right timing. Depends on alloy, quenchant , tempering temp, time in water. We had lots of parts to play with and we were metallurgists !

 

[Willie71]

You can get really good activity with parks #50 with a much lower chance of cracking a blade.

This is true, but water quench (brine) is really fantastic. I hated losing 50% of my blades though. I’ve only lost one in brine/oil, and zero in dt-48.

 

[Willie71]

Water quench really adds stress to your blades. Watch this:

 

[kuraki]

The one time I tried it the edge cooled too quickly and the spine pulled the edge apart as it cooled. When I decide to try again I will leave my edge 2x as thick as normal.

 

[Willie71]

The one time I tried it the edge cooled too quickly and the spine pulled the edge apart as it cooled. When I decide to try again I will leave my edge 2x as thick as normal.

Water quench pulls the edge apart, oil quench pulls the spine apart. In my experience anyway.

 

[Natlek]

Water quench really adds stress to your blades. Watch this:

I've been watching a hundred times this video and I was really convinced that there must be differences between vertically and horizontally quench ?

 

[Willie71]

I've been watching a hundred times this video and I was really convinced that there must be differences between vertically and horizontally quench ?

It’s the steel thickness. The spine moves more as it goes from square/recrangular structure, to trapezoidal (not sure if that’s the correct term) then back to square/rectangular. There’s more steel to expand on the spine, but the edge transforms more quickly, resulting in the movement you see here. Vanadium helps pin the grain boundaries helping to prevent cracking. This is why W2 is more stable in brine than 1095.