Some of us are new to your work and don't know much about your background. How did you start making knives? Also, I am wondering about your knowledge of heat treatments and optimizing steel. In short, how did you become a wizzard with steel?
I got my first real job in industry with a manufacturer in Raleigh back in the mid 90's while I was going to NCSU. I worked as a design engineer and machinist. We needed bending dies heat treated so I took more of an interest in heat treat. It was a subject covered in my materials and processes classes and in mechanics of materials, but not in depth. We'd also done some in a shop class, but it was very rudimentary. Our school library was about 12 stories tall (huge building with a lot of specialized information), and the 5th floor had a tremendous section on metallurgy. We also had some phenomenal professors, Dr. Armand Cook and Dr. Wayne Place in particular were willing to spend some time with me to help me wrap my head around some of the concepts. I wanted to learn it because I'd always thought it was cool. The addition of carbon to iron, when manipulated with heat makes it hard and strong <--- that's almost alchemy. And there's no chemical reaction. There's not even any molecules. It's simply carbon atoms physically jammed between iron atoms laid out in a metallic crystalline matrix, made possible because of a FCC->BCC flip caused by heat and carbons ability to flow in that crystal. That's nerdy neato.
As a boy we lived in a neighborhood with a lot of woods and I had machetes I'd use clearing trails and building stuff. One in particular wasn't well heat treated and wouldn't hold an edge so I took it upon myself to re-harden it in the family stove, quenching it once red hot in a bucket of water. This was about 30 years ago, I had no idea what I was doing. Looking back on it, the steel must have lacked much carbon because I didn't know to temper it, but it wasn't brittle.
I made several poor knives in the 90's, lacking knowledge of proper HT and geometry.
Around 2001 I opened shop and we got a good industrial HT oven for tool and die work. I did a fine job of doing HT on tool steels, but nothing special. I made my first knife in D2 around 2002 or 2003. It was done with the industry standard HT and didn't hold an edge well, but it was better than a walmart knife. My father in law and I had pocket knives with this D2 we used for a couple years.
I began learning about tweaking heat treats for D2 around 2003. I still lived in Georgia and the internet was a thing, but not like it is today. Cliff Stamp was around back then too and even way back then he was talking about quench speed and cryo which made me more aware about those things. Love him or hate him, it was Cliff, not Roman, who started me experimenting with that.
At first a lot of what I was doing was frowned upon by other makers because I was deviating from industry standard. It was considered hype by some. There were those that said that if you can't get the best HT a steel is capable of using the industry standard you much be doing something wrong. It was about this time frame that Keven Cashen, a truly knowledgeable Mastersmith, was sort of "cleaning house" and encouraging people to learn about metallurgy and stop putting stock into old wives tales like edge packing, quenching in bear piss, and forging aligned with magnetic north. But with people's increased understanding of industry norms and skepticism of unorthodox practices some people were (understandably) skeptical of what I was doing. (though it is vindicated in current metallurgy literature). It was about this time I took an interest in comparative testing with standards rather than forming judgments based solely rockwell hardness and cut testing with a lone blade.
It was also about this time I had Paul Bos heat treat some knives for me to make industry standard "standards". He did a few for me and this was when I decided that the HT you can get from a commercial HT shop leaves a lot of performance on the table.
A few years ago my biggest customer (for the machine shop) was having a problem on their high volume fiberoptics cable production lines. These cables come reinforced with a fine Kevlar fiber jacket. This Kevlar is often cut with special serrated scissors, but not in high volume production. They use a cutter with carbide blades, and they're very expensive, but they're good for 10,000-15,000 cuts in this very difficult material.
They were trying to rework this device and were having problems and I got involved in the project. It was about this time I was really getting my D2 dialed in, with prequenching, a second soak tweaked to that particular batch of steel, and a quench speed and depth tweaked for that material where I was getting edge stability in D2 better than anyone and I thought it would be a good material for the application because of its micro serrations from the large chromium carbides. Long story short, we were looking for about 5000 cuts from a blade set (being steel they were much less expensive than the carbide blades) and we ended up getting 250,000 cuts, exceeding their expectation by a factor of 50, and exceeding the original carbide blades by a factor of at least 15X. This was a big deal and it was about this time that I stopped sharing my process with other makers. I had invested quite a bit of time in it. It was also about this time I became frustrated in people's lack of interest in D2 and in the variability in the steel from batch to batch and started putting more effort into 3V.
3V has the exact same issues with edge stability as D2 for the same reasons, so when I started working on 3V I knew what tweaks to look at and immediately got good results. But I made some assumptions and did not test every variable. But this early 3V worked well and got some people's attention. I'd like to point out it was based upon my own tweaks from D2, not Roman's 3V tweaks (which are similar and were developed concurrently).
There were a couple problems with 3V in 2015 and it effected me and other makers using it. Dan and I had been talking about 3V for a while because he and I both had worked on a low temp tweak for it that avoids the problems with the SHH. He'd turned Guy on it too, so when we saw these issues the three of us put our heads together and started experimenting with the process. I did the work at my shop with blades provided by Guy and in collaboration with Dan. At this point I'd worked in industry performing R&D on product and process optimization for years and had a pretty good technique for breaking a process into its variables and testing their effect on the final outcome and each other. The key was controlling variables and the test procedures. A lab grade HT oven, a good cryo chamber, RC tester and the ability to wet grind consistent geometry for building test samples reduced the noise to signal ratio and I got to work. Several of the assumptions I'd made about 3V that were based upon D2 turned out to be wrong. And there are a few things that are counter intuitive. There is a lot of common knowledge that isn't entirely correct and there is something that may be specific to PM steel whose effect is visible but the cause is not really known. And that's the cool thing about R&D <--- you don't always have to know the reason why something behaves the way it does. It's nice to know, but in the end what's most important is that the result can be verified by testing and is repeatable. Thus the absolute need for real testing when developing a tweak.
And that's in in a rather large nutshell. I've been interested in HT since I was a little boy, I got exposed to it more in school and eventually set up to do it myself. I learned from books, people, internet and by doing and testing. Work I did on D2 led to more work on 3V that was eventually optimized into what we're doing today.
TLDR?
