Brine Quenching 1095

N

North Star Forge

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May 1, 2006
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Anyone have any experience brine quenching 1095 using a clay coating of satanite? I have some 6" blades I am thinking of trying it on and would also like to try it on some smaller 3" ones as well to pull out maximum hardness. Anyone have any thoughts about proceedure? I can bring them up to temp in either a propanes forge or a small kiln. Thanks for the help. -Scott
 
I did 3 blades (1095) in brine last weekend. They're not polished out yet, but a quick etch in vinegar showed some activity. Luckily I aint cracked one yet. I used my gas forge and normalized 3 times. Quench went full in to room temp brine, I noticed a nice even boil when I lowered the blades in (not slow but not real quick either). The best thing is I didn't feel any poink through the tongs. The blades skated a file well and no weird noise when I tapped the blades with my hammer handle. The blades were 6"x 3/16"with hidden tang.
I'm by no means at the top of the learning curve but trying it gives me more confidence and keeping records really helps. Hope this helps you some.
 
OK, I assume this is not the first blade you've hardened? Brine is the fastest and harshest quench.It will break a fair percentage of 1095 blades quenched in it.Water is a little less violent,but still risky.Fast oil,park's #50, is the best for 1095 ,IMHO. If you are hell bent on doing the brine thing to get the wildest hamon you can,then make sure the brine is at 130-140 degrees F.Quench quickly and hold your breath.If you don't hear, "PING",then let it cool for about 1 min. and take it out and see if it is cracked.If it survived, scrape off the clay and temper AT ONCE. 400F for 1 hour,twice.
I wish you well,but make several,you might get one to work.
Stacy
 
Stacy,

Why not an interrupted quench? You've either missed or hit the pearlite nose after the first 2-3 seconds. Why not go in for a 3 count, then remove for a 3 count to let things equalize, then go back in, etc.? As you so correctly pointed out, the medium is inherently risky, but I think just leaving the blade in the brine makes it even more so.

John
 
In previous attempts I cracked two blades with the interupted quench.
After a 3 count I could feel the blade crack through the tongs on the second dip but the three blades that were full quenched did not crack or warp.
Dumb luck maybe, but the full quench felt nice and smooth. All quenches were done with clay.
 
RUJOCO,where on the Blades did you find they cracked ? All in the same place ? Different ? What size Blades ? Hey just curious , I'm trying to learn something too . :)
 
John, If the quench is interrupted then there will be multiple and different stresses applied to the blade.That is why creating the sori on a katana is such a risky quench.The first 3 seconds will harden the edge into martensite,the second quench will create pearlite under the clay and cause differential expansion/contraction between the two structures.The result may be a either a straight blade (on short blades) ,a warp or a curve (or both) if all goes well (on longer blades).The other possible result is that the expansion/contraction differences between pearlite/martensite will rip the edge apart,creating a crack or a full break.
In an effort to avoid failures,I advocate for learning to get reliable quench results in the proper medium for the steel first.After gaining consistent results for a period of time,then try exotic quenches.I find that fast oil will create a nice hamon.The difference between brine and water is minimal.If a max hamon is the desired result,use water. The thing that escapes many newer makers is that the hamon,while being attractive, is not a reflection of the blades edge qualities or durability. A hunter with a hamon is no better than a hunter with a differential temper,just prettier.
If you are clay coating the blade to get a soft spine and a hard edge,then a single quench in fast oil is much better than water or brine.
Stacy
 
David,
The cracks were almost in the same place on both blades. 4" in from the tip and roughly 3/4" max from the edge up under the clay. I suspect the distal taper to be the culprit because the cracks correspond to where the spine (3/16") tapers to the point. Both blades were give or take 6"x 1 3/8", flat ground with the edge left at least 1/16" which looks pretty thick to me. I'm gonna stick to a full quench for now.
I have some 1/8" 1075 stock which I'm going to try, but only profile the 4"blades (2), then harden and temper. Then I'll grind in my bevels. Even blade geometry might help. These are experiments to help me nail down a repeatable formula only. I also don't believe every blade made needs a ripping hamon. My oil quenches have been very successful. Just trying to learn also.

I also noticed that there is never any warping with the brine, only pings. Compared to oil quenches which I do get warps occasionally, but aren't a big deal to fix anymore.
 
Thanks for all the feed back, I am anxious to harden the blades, probably some time this weekend. In response to a couple of the questions, these arn't the first blades I have done, I have been making knives off and on for about 10 years and most of that time has been concentrated on Scandinavian styles, either laminates or Finnish puukko style blades (I spent a year in Finland study with a master smith). Up till this year I have mostly worked with edge quenching in either oil or "Godard's Goop" with good consistant results. The past year I have been toying around with brine and water to bring out hamon lines with mized results and am just looking for thoughts and feedback.
It is interesting that some of you bring up interupted quenching as this has been one of my questions. I have been reading some of the other threads and it seems that some advocate interupted quenches (in 3 out 3 etc) and some don't. Sounds like I will try both to see what happens. In the past I have brought the brine up to about 150 degrees and have had pretty good results.

My other question is what are your thoughts on heating in the forge vs ramping up in a kiln and giving the blades a 2-3 min soak (on the smaller ones) and 4-5 mins on the larger at 1450 degrees? Advisable?
Thanks again for all the help! -Scott
 
Experimenting is a good idea once you have the basics down (as you clearly do). Ramping and soaking in a HT oven will be far superior to a quick heat and dunk with a forge. Hot brine is safer.You should make three identical blades and do one in brine,one in water and one in parks#50 (or equivalent fast quench). See what the results are.Let us know.
Stacy
 
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