Anybody still quench with fat?

Now, TEMPERING is a different story. I'm glad stacy brought that up. Liquid media would be much more consistant than a cavity of air.

I don't even know what to say about the lion fat... so I'll take the opportunity to say nothing.
 
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Ben Lilly trapped and skinned more bear and lion than any man alive, forged his own knives and worked with what he had. He was always on the move, when he bought a new pair of boots he would nail a couple of layers of old tiers on the soles so they would last. Guided for Roosevelt, according to Roosevelt he had more endurance than any man he knew. He had no home base and naturally would not have been interested in carrying a gallon of quenchant with him.

His knives were probably the most tested by one man during his time. His methods had to work, how well we don't know. I would not sell him short.

Brian: what were the two books? I have Dobie's book, but not the second one.
 
Yep thats the one its kind of like a diary but also kind of like him just telling stories about what he had done. The copy I have is pretty old.
 
tryppyr said:
I think we tend to dismiss questions like this a little too quickly because we tend to assume everyone wants a knife to be the same way we want knives to be.

For example, we dismiss quenchants because they don't achieve optimal hardness. What if that isn't the main goal? What if the main goal is toughness? Would it change anything if the main goal was to achieve a certain look?

Does it naturally follow that because one quenchant achieve optimal results for knives that it would do the same for spear heads, swords, or other edged instruments made from the same steel?

Obviously, I'm not coming from a place of expertise. I'm just saying there are more reasons than hardness why someone might choose a quenchant.

- Greg
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I didn't see anyone address an important aspect of this question. Obtaining the maximum hardness isn't the goal of using a good quenchent. You're trying to minimize undesired structures, a side effect of this is usually a higher as quenched hardness. So, one measure of the effectiveness of the quench is the as-quenched-hardness.

For example, a blade made of 52100 quenched in cow poo may have an as quenched hardness of 57, but the same blade quenched in canola oil may have an as quenched hardness of 65. Temper the cow poo blade at 300 and it may be 55 and the canola blade at 450 and it may be 59. By most meaningful measures, the canola blade, even though harder, would still be the tougher of the two.

It is important to compare apples to apples. Two blades at the same hardness but with different quench rates and tempers are going to be different. Overall, I think you want to control hardness with tempering, not quenching.
 
Fat may work fine for some steels, only testing will prove that.

Some steels need a fast quench, some need a slower quench, some need to be air cooled to harden.

Fat would probably be somewhere in there, I would guess medium to fast but not fast enough for water hardening steels. That's just a wild guess though...

I wrote this up to help answer this question http://www.bladeforums.com/forums/s...lection-for-Beginning-Knifemakers-My-Thoughts
 
Nathan, you took my example too literally (as did everyone before you) and missed the main point.

There are other reasons besides hardness and toughness to do things differently. If someone quenches in blood, you can bet it's not because they have thought through the internal structures, nor are they likely to care. They're probably doing so for reasons completely outside your area of interest as a knifemaker.

Ditto for the use of fats as a quenchant.

You need to step a little outside the box sometimes, guys. You need to accept that the whole world doesn't share the same priorities you have. That's all I'm saying.

So maybe the unicorn blood and virgin's tears still serve a purpose... to sanctify a blade and make it appropriate for some usage. Maybe the lion fat is all we have on hand if we're living in the wild off the fat of the land. And maybe there's more to the choice than we'll ever understand.

- Greg
 
bladsmth said:
My friend quenches in fat all the time. He pre-heats it to around 400F and quenches potatoes, onion rings, fish, and chicken in it. He says the type of fat make a big difference. By selecting the right type of fat and doing the quench at the right speed, he gets the desired hardness. He is also getting a very low toughness....which is a good thing in his business :)

When not in use for other things, he sometimes tempers his knife blades in the same fat.
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I almost choked on a Dorito laughing when I read your response... Funny!
 
tryppyr said:
Nathan, you took my example too literally (as did everyone before you) and missed the main point.

There are other reasons besides hardness and toughness to do things differently. If someone quenches in blood, you can bet it's not because they have thought through the internal structures, nor are they likely to care. They're probably doing so for reasons completely outside your area of interest as a knifemaker.

Ditto for the use of fats as a quenchant.

You need to step a little outside the box sometimes, guys. You need to accept that the whole world doesn't share the same priorities you have. That's all I'm saying.

So maybe the unicorn blood and virgin's tears still serve a purpose... to sanctify a blade and make it appropriate for some usage. Maybe the lion fat is all we have on hand if we're living in the wild off the fat of the land. And maybe there's more to the choice than we'll ever understand.

- Greg
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Greg, that's an excellent point. IF we're talking about physical performance as defined within an empirical worldview, Nathan, et. al. are correct. If physical cutting performance is less important than spiritual power or spiritual symbolism, obviously the quenching methods can, and should, be adjusted to imbue the blade with the desired characteristics. Which qualities are more desirable, or even which ones are even real, is a matter of perspective and better debated by theologians and anthropologists than knifemakers and craftspeople. I've made significant income as all 4 at some point or other in my life, which leads me to conclude that most perspectives have something valuable to offer, even if few are 100% correct.
 
Quenching in fat may be for the same reasons someone pattern welds steel, antiques the fixtures, leaves a brut de forge finish, or makes period swords and daggers.
 
Nathan: Which would be the tougher of the two? I don't know, but hope I have the time to compare the two.
 
Ed Fowler said:
Nathan: Which would be the tougher of the two? I don't know, but hope I have the time to compare the two.
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Ed,

I don't honestly know. By the strictest definition of toughness, if you were to notch both blades and swing a pendulum of a particular mass through them and measure the distance the pendulum travels after impact you could calculate the energy absorbed during the fracture and generate an impact toughness number. While this number can be a useful number when comparing apples to apples, I don't know how meaningful this measure of toughness would be in this application.

However, to you and me wanting to know which blade is less likely to fail catastrophically without warning, we'd probably both want the "properly" heat treated blade, and here is why: The cow poo blade, with its low temper (300) and mixed microstructure is a combination of weak brittle tetragonal martensite supported by weak and brittle bands of cementite and weak (but ductile) ferrite. It is in essence a fragile form of martensite supported by low strength structures. The "properly" quenched blade that also got a higher temper (450) would have a relatively homogenous structure of well tempered (cubic) martensite which is considerably stronger and more durable and could even perform well as a spring.

Please be aware I'm not commenting on mixed structure blades as you make them with a differential heat treat, I'm talking about mixed microstructures. I'm talking about comparing the attributes of a relatively soft mixed structure blade with a poor quench to a relatively soft martensitic blade with almost a spring temper. I want folks to understand that you can't compensate for low hardness out of quench by using a lower tempering temperature. It isn't the same thing. A successful quench will give a high as quenched hardness, otherwise you'll be compromising on the performance of the blade, regardless of how soft it is ultimately tempered. I hope this makes better sense.
 
I destroyed several knives early on, trying to use 'goop' variations.
The problem with it is that the quench effects on steel are unknown. If you're trying to save money, using unknown components is a lousy way to go about it....

Canola is well understood, and typically cheaper than pork trimmings, for instance, after you consider the trouble to render the lard out. (yes, I've tried)

Besides, Canola is 100% fat. Sez so on the label. :D

-Daizee
 
I think Greg has a good point... good lateral thinking.

There could be reasons other than pure performance to give validity to using a certain quenching medium. In terms of animal fats,… possibly a “period piece“, (historical reproduction, creative anachronism etc.) or maybe a “theme and/or concept knife“, (lion knife, cow knife, horse knife etc.).
 
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I am not claiming it will be better, and appreciate your comments. I am just curious and want to experience what we think he did.

Next week at the ABANA Conference in Rapid City South Dakota a metallurgical mining engineer will be setting up next to me, we are both doing demonstrations. He is a graduate of one of our seminars about a year ago and has been working with multiple quench. For those who want technical explanations, he will be able to give them.
 
Well, this is a bit dated, but Alexander Weygers "The Complete Modern Blacksmith" he strongly recommends quenching small and delicate tools such as carving gouges etc in rendered lamb's fat. Claims it leaves a very clean surface. I do not think that this would compare at all with a modern quenching agent in either quality or price (anything lamb is expensive right now). Weygers books are really the best of the older books on advanced tool-making for blacksmith. Lots of other ideas in the books that are sort of frowned on or outdated, such as junkyard metal usage and abrasive impregnated rubber wheels for sharpening (dangerous).

However, for detailed instructions on certain things like making drill-bits, gouges and carving tools, and tinsnips, still pretty accurate and useful. 3 books were published in the mid-seventies, "complete modern" is all 3 together. I use books that are over 100 years old for patterns and information, especially agricultural equipment, but sometimes historical methods have to be "tempered" with a grain of salt.
 
I had asked in a previous thread about using ATF fluid on 1095, ended up getting some canola oil that worked out very nicely. Im sure all you veteran knife makers didnt start out with a engineered quench oil, so what did you use on your very first blade ??
 
metalmole said:
I had asked in a previous thread about using ATF fluid on 1095, ended up getting some canola oil that worked out very nicely. Im sure all you veteran knife makers didnt start out with a engineered quench oil, so what did you use on your very first blade ??
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A professional heat treatment company. :D
 
Man, I'm sad I missed this one the first time around, but got a good read out of it just now. I about near died laughing, and learned a lot in the process.

Also, I agree with Greg on his answer. I send my blades out to Darrin Sanders for heat treat. Whether he uses canola, or Parks, or unicorn blood and virgin tears, I don't know. I'm hoping not cow poo. But whatever it is, he does a great job.
 
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