Water quenching 1084? Also building brick forge?

Chiro75

Chiro75

Joined
Feb 4, 1999
Messages
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I tried, once, to water quench 1084 and I cracked a blade. After seeing some pictures from Burchtree I have a desire to try again for whatever reason. Is 1084 a bad steel to water quench? Do I need to heat the water like I do when I oil quench?

Next topic: I bought a few fire bricks and tried to make a Goddard style brick forge so I can HT longer knives than 4" blades. I went to a brick store and bought a few "firebricks" but I wonder if they weren't the right thing. They were made for use in outdoor applications like outdoor firepits. They're not super soft or brittle like others have talked about, though, and they don't seem to help me heat blades any better, although maybe I put them together wrong? Basically, I dug a shallow groove in the center of two bricks and knocked out a space to put the torch in from the side. Seems to be the same thing Goddard does in his $50 knife shop book, but my brick forge is a piecer. Any help?
 
Due to the high manganese content of 1084 a water quench really isn't recomended. It was designed to be and is an oil quenching steel and water is just too violent a quench for it, not that it can't be done. You'll just crack many many blades before you develop a technique that works.

Water quenches are used mainly on shallow hardening low alloy steels which need the fast quench time to develop a useable hardness. Such steels would be 1050 or 1060 or a steel like the low manganese 1086 modified, a custom made steel, that Howard Clark uses.

The hard firebricks you are using do not have the refractory quality of the bricks that Wayne Goddard talks about. The firebricks you need are very soft light bricks you can carve with your thumbnail and have to be purchased from special companies (possibly a brick company) that supply furnace construction or repair services.

In any case no matter what you do, you will be hard pressed to reliably heat treat (emphasis on reliable there) knives with blades much longer than 4" unless you build a forge of some kind. There are many options ranging from low tech charcoal (the real stuff not briquettes) to propane forges. Alternately if you have access to an oxy/acetylene rig you can use it to heat the edge portion of your knife blades, a process that also takes a bit of trial and error.

Good luck, and go to an oil of some kind for your 1084. Used hydraulic fluid wil work as will just about any vegetable oil all the way up to commercial grade quenching oils specifically for heat treating. Watch your temperatures too, overheating a steel AND using water is almost sure to result in failure.
 
You can get the soft firebrick from ceramics supply houses -- I find them at Campbell Ceramic Supply in Richmond, VA (804-329-0109). Check with the potters in your neck of the woods, find out where they get their supplies from.
 
Steve -- playing in water will give some seriously cracked blades (I've got many) and I wouldn't recommend it. Like others said, some light oil will get you some great hamons.

But for some reason, I just feel the urge to dip in the water bucket sometimes. :D
 
I think the violence of water tends to give more interesting effect to the hamon, such as Fogg's knives, etc. Maybe I'm wrong, though. I get great temper lines with oil, and have yet to have a cracked blade, but I want Fogg action on my knives! :D Granted, the steel choice makes significant difference, too. Maybe even the forging vs. stock removal would make a big difference. I don't know enough metallurgy to have any idea about that. Since it takes me a month to make a knife I'll probably stick with oil, though! :D
 
You've got to realize that the action in the hamon is very closely related to the type of steel as well as the type of quench. Many of Don's knives are made from the same 1086 modified that Howard Clark uses. Many are 1095, which generally has a lower manganese content as well and will develop a nice hamon. To get a lot of hamon activity a shallow hardening steel should be used, I don't know if any of the oil quench steels could be classified as shallow hardening, medium maybe but not shallow hardening.
 
A lot of the activity also depends on how you coat your blade and how you heat it. A lot of variables in there. But, that's what makes it so exciting. :)
 
Michael is right, there are many many variables. Blades, especially clay coated blades behave very differently when quenched in water or oil and the alloy of steel used complicates matters further.
 
OUt of curiosity (I like doing my own HT, of course), does anyone offer differential HT services like this? It's be sort of convenient to finish a Japanese style knife and send it to someone else to do the hard work! ;-) Let 'em polish the darn thing, too! :D
 
Heat treating 1084 is simple if you use oil for your quench.
I've been making knives for over 20 years, and been quenching in oil with no problems. I get fantastic hamons on 1084 with oil, why would anyone want to use water :confused:

All the best, Don Hanson
sunfishforge
 
Every blade of 1084 I have tried to quench in water has cracked no matter how quickly I tempered it. I get great temper lines by quenching in oil with 1084. I won't quench in water again.
Kyle Fuglesten
 
kile said:
Every blade of 1084 I have tried to quench in water has cracked no matter how quickly I tempered it.
Kyle Fuglesten
Click to expand...

"no matter how quickly I tempered it" :confused:
Kyle ,,, tempered it or quenched it?

full quenching bare steel in water, the quench should be in and out quickly very quickly, if in to long it will tighten up real fast :eek:

edited to add Full..
 
I don't mean to hijack, but where are you folks getting your 1084? I'd sure like to play with some of that stuff.
 
kile said:
Every blade of 1084 I have tried to quench in water has cracked no matter how quickly I tempered it. I get great temper lines by quenching in oil with 1084. I won't quench in water again.
Kyle Fuglesten
Click to expand...


A wise man once told me, "The only thing water is used for in my shop is drinking!"

:)
 
BurchTree, I've been told that 1084 is no longer being made.
Start looking and asking around, I'll let you know if I find any,
I have not run across any in a while. I do use 1084 powder in my damascus and have thought about just forging out some bar stock of the powder, might be cool???

Danbo, water is good for some things :D

Don Hanson
 
Excellent thread.

I've just started experimenting with '1084' from admiral. It came with a data sheet. Looking at the carbon content it should be called something like 1072.

Guy, what percentage of manganese do you consider low?

In any case my first blade was water quenched. No cracks. However, I didn't have enough of the blade up to temp and only got the edge hard - not up to the clay line. The next attempt I got the blade temp up, but cracked like crazy.

Blade number 2 is going back to the oven (instead of the forge) and using oil.

Steve
 
I have made a few peices with 1084 some in water some in oil... I have fround that most of the difference is with the curvature a peice takes... I get much more curvature from quenching in water than in oil...

I have been heating my blades(and clay) up in an oven not a forge or source of non spread heat too... triple normalized before HT and a nice slow rise to temp... and they seem to take a gogeous curvature from the edge....

Chiro... if you need a few of those soft bricks let me know!! I got 3-4 cases of um....

Alan Folts

alanfolts@hotmail.com
 
Sando said:
Excellent thread.


Guy, what percentage of manganese do you consider low?


Steve
Click to expand...

Well, 1084 certainly has a fairly high Mn content at around .70-.90% or thereabouts. Compare that to 1095 which should be down around .40 or so BUT I see on Admirals website they are showing it much higher so go figure.
Steels like W1 and W2 (classified as water hardening steels) should be around the .30-.35% mark. Remember, practically any alloying element will increase the hardening capbilities of steel, carbon being the big boy. But even relatively minor additions of other alloying elements drastically affect the depth of hardening. This is why a medium carbon steel like 5160 (a deep hardening steel) is capable of hardening as well and reliably as it does. Mn is just one of the more common additions to steel to make alloys that harden reliably and to a greater depth, an effect that is very important in industrial situations especially in round sections (think axles made from a tough medium/low carbon steel like 4140). As an alloy gets more complex, hardening can happen in still air. Crucbles L6 is a good example of this as well as all of our commonly used knife stainless steels.

If I remember right, Howard Clark's 1086 modified has a pretty low Mn content of around .20-.30 with a touch of Vanadium as a carbide former, quite similar to W2 actually.
 
Thanks Guy,

I'll review my data sheets on the admiral stuff. FWIW I ordered two different thicknesses and the stats are slightly different.

Steve
 
1084 can be water hardened succesfully but must be brought to heat gently and extremely evenly and quenched in stages like 2 second dip out for a sec back in until it has been quenched and only full quench afeter you have haredened the edge then as it loses cherry do a full quench i have had it reach approx 62rc this way but i warped many blades before i got the technique just right. the biggest thing is the heating i find and if one side of the piece is even just a few degrees cooler it will warp or crack the blade under the shrinking stresses.
 
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