Guys, this has been a great thread. I want to add a few comments that seem pertinent, especially for some of our newer makers. Absolutely none of the following comments are intended as a denigration of any maker or their methods.
I started making knives a little over ten years ago. Like many, I had a chance meeting with Bob Engnath and away I went. I learned to use the tools I had; a torch, home-made quenchants, etc. I learned to read colors and shadows for my heat treatments. As time went on I believe I turned out some pretty good knives. But, some funny things happened. I have always liked to learn new things and have never been one to fear change, albeit I am often slow to do so. [
] As I progressed I began to ask myself how I could improved my skills and my blades, especially the quality of the heat treatment, which I clearly recognized was the most critical aspect of a great knife. I did not want to make decent knives. I wanted to make great knives. I decided I needed to learn a lot more about steel and bought Bill Bryson's book after a recommendation from a friend. That really got my attention, but I was still slow to act. Pretty soon Nick Wheeler quit using stainless and started down a similar road with forging, heat treating salts and testing, frequently sharing his results. Thanks, Nick. My friend Rick Leeson got copies of the ASM heat treating manual and the one on quenchants and started sharing them with me. Thanks, Rick. Roger really got me thinking when he first got his oven and began extensive testing on all kinds of steels and then made the switch to a real quenchant. Thanks, Roger. It got worse. Some darned metallurgical engineer joined the boards and started giving us hell! [
] Thanks, mete. Then, along came Kevin with his eloquent style and willingness to challenge "the old ways", having been down the same road himself. Thanks, Kevin. There were lots of others here too: Dan Gray, Fitzo, Raker, Laredo and Sando, to name a few.
There is a point to all this. All of the above forced me to really start taking a look at my processes. Steel is one of those things that came out of the realm of art and into science long ago. It is one of the main building blocks of modern society and is undergoing constant research. I reached a point where I had to ask myself if I really understood what was going on in my steel. Yes, I could make a knife that could pass ABS testing, but was it the best I could do? I came up with endless questions, like: how do I know what kind of transformations are occuring in the steel when using a torch? How can my steel be properly transformed if it was impossible for me to accurately gauge temperature? How can a torch accurately heat all parts of a blade equally? What happens if all parts are transformed at different austenitizing temperatures? How can I ever be certain that the steel was properly soaked at the right temperature given the other questions? If industry was so specific, why was I doing it differently? I could never be certain that 100% of a blade was normalized, annealed or austenitized evenly?
Then came what to me was the most thought provoking question of all after realizing that we all use ovens of some type to evenly distribute the heat when tempering our products. Why was it then, that so many of us did not give the same kind of attention to the other phases of heat treatment? That was a real bombshell to me. If all of the above were true, then how could I be certain that there was not some weakness in a blade even if it did not show up in testing? Why am I using home-made quenchants when there are products designed just for this purpose? What are the weaknesses of the "home brew"? The bottom line is that I could not answer any of the questions and realized that I needed to start over. And that, is where I find myself today.
I now have a good Evenheat oven and a Rockwell tester. I spend more time making test coupons trying all sorts of combinations with time and temperature. For now, I am spending more of my time testing. Currently I am using Tough Quench and getting very good and consistent results. I am still playing with soak times and temperatures as noted in my question to Kevin in another post, but I am very pleased with the consistency I am seeing. My Afghanistan knife was the first with a new heat treatment and I know the owner has been pleased with its performance.
This leads me to my final thoughts for people like Brian and Steve. You guys make great knives. I suspect however, you will soon be asking the same questions I did. I know it takes time and money to add equipment to the shop, but you will never be sorry. Good equipment and procedures will make a world of difference. Yes, you will have to stop and do a lot of testing with your new equipment and steel choices, but the results will be worth it.
BTW - I told my lovely wife that the ASM heat treater's manual along with the one on quenchants would make nice gifts! Fortunately, she just smiled and never said word. That is usually very good news. [
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