Clay hardening

Use stove cement, refractory cement (used for lining the forge), or any high temperature mortar.
APG#36 is one of the most popular mortars.
Satanite works fine,too.

Stacy
 
Satanite is much easier to use, imho. It's also generally cheaper and you don't have to worry about it drying out (it's already dry!).
 
Er... I don't have any sources here, but I have a steady source of refractory concrete, and a half sack already there.
Will mix up some, and use it to do a blade, just to see what happens.
With 1075 should I quench in oil or water?
 
Eh... I swore to stay away from water after "pinging" a little damascus blade from Aldo Conto last year... crapola.
But perhaps with the clay the 1075 would be safe in water, and I'd get a better temper line? I will make a test blade, a THIN one, and try it in water.
If it doesn't go ping I'll let you know, and will try bigger blades.
If it pings, it will be oil.
Sure as hell I won't put a W2 blade in water. That's hydraulic fluid / oil only.
 
You could try an interrupted quench, water then oil. Also, I'd scrape the clay off the spine to reduce curvature, less chance of pinging it. Have you been using water or brine in the past? 1075 will require brine. I would prefer to use water/brine or professional quench oil with clay.
 
Brine? :confused:
Brine is a harsher medium than water... :confused:
If it pings in water, it will shatter in brine. :eek:

I mean: salt in water will make the solution more dense, and so more ready to subtract heat from the blade.
Salt also rises boiling point, so it will reduce or delay the vapour jacket that will partially insulate the blade, and make the quenching even harsher.
 
Not saying you are wrong about speed, but 10xx series steels, by and large, are brine quench steels, to the best of my knowledge. Here are a couple references for you:

Bob Engnath:
http://engnath.com/public/harden.htm

Bob Engnath said:
1050 to 1095 steel Brine quench from 1475 to 1500 F. hardens to RC 60 to 65. Draw immediately. Oil quench at the same temperatures for slightly lower hardness. Shallow hardening and can be done in the Japanese style with a decorative temper line."
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Bob Engnath said:
"Water hardening is a mis-used term. In virtually all cases where a steel is referred to as water hardening, they're actually talking about quenching in brine, heated to a temperature of 170 degrees, (F) or above. Brine is made by dissolving non-iodized salt in water until a egg will float in it. Jim Hrisoulas uses bluing salts to make his brine. The whole idea is to raise the boiling temperature of the liquid and make it transfer heat better. Brine will eat right through an ordinary steel barrel in a very short time. Jim Ferguson just mixes in borax and detergent to reduce the surface tension."
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Joe Walters:
http://www.knifenetwork.com/forum/showthread.php?t=36719

Joe Walters said:
Water works well, but you need a large mass. I use 50 gallons for sword-sized blades. Brine, I feel, is a better quenchant in a 10 percent solution (by weight). It's faster, but doesn't wreak havoc like water. It's not so much the speed, it's the steam jacket that plain water forms against the blade inconsistently down the length, thereby cooling at different rates. A fast oil works well with 1095, too, but you need to precurve your blade.
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Joe Walters said:
I agree with all of your points, however #5 and #7 I gotta disagree with. A saturated or super-saturated brine solution does not quench as fast as plain water. A 10-15% solution quenches faster, and in almost every case, will result in fewer cracks. Volume of water is very important. As a rule I use 1 gallon to inch of 3/8 (or less) stock being quenched.
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Joe Walters said:
I didn't mean to come off as argumentative, rather I disagree, and my disagreement should be read as an opinion. My understanding of brine is that it eliminates the vapor phase as well. However, the speed of the quench of brine is adjusted by its concentration. A 25% solution of brine, or a 'saturated' solution quenches slower than water. What causes cracks isn't the speed of the quench, in my experience, it's the steam pockets causing uneven quenching on the blade. Maybe your blades are cracking because brine was too fast. I'm not sure, could be. I've never found that to be the case using a 10 to 15% solution of brine. I use low austenizing temps and eliminate all stress risers, though, and get a crack maybe 1 out of 50 blades, and it usually winds up being uneven grinding or a portion where clay popped off too early.
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J. Arthur Loose:
http://www.knifenetwork.com/forum/showthread.php?t=36719&page=3

J. Arthur Loose said:
1095 *is* a water quench steel. Alone of all the 10xx series steels, 1095 has very little manganese, which is the alloying element in 10xx steels that allows more time for quenching. In my experience, a "water quench," in the industrial use of the word almost always indicates heated brine, which may or may not be faster but is definitely less stressful than quenching in plain water.
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Sorry for the outside links, these are the topics I could think of off the top of my head. I spend a lot of time outside of here. Maybe one of the resident metallurgists like Kevin or mete can come in and slap me around for being wrong about this.
 
The fastest brine is a 10 % solution of salt [NaCl] in water. Tha basic action of brine is to eliminate the vapor phase. ...Heating water actually reduced quench rate !..Interrupting the quench just adds another big variable !!
 
Urgh!
I think I'll make a sacrificial blade, clay coat it, and test the brine on it.
If it shatters, well, it's back to oil.
If it survives, I'll try it on a good blade.
I'll try 10% brine.
It's 10% in weight, right?
 
I believe it's by weight, yes. You just keep adding it until an egg will float on top if you're not sure. That will be right around 10%, not exact, but it will work.
 
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