When I first began camping in my adult life, my primary knife has been a KA-BAR USMC fighting knife. I still believe that it's a good value and has held up incredibly well to significant abuse. There is something special, however, about using your own gear. I started looking for inspiration (stealing) from more expensive knives. I wanted a knife of significant mass and length for chopping/batoning, the control of a thumb ramp and a smooth cutting surface for more fine work.
After several iterations, I settled on design 3. From this, I began drafting in Inkscape. While not strictly necessary, I had a few dimensions I had measured on other knives that I wanted to be sure carried over. Printed it, cut it out and traced it. On future knives I think I'll simply use a combination square, sharpie and alcohol for erasing and skip the drafting stage.
For this project I was new to heat treating, so I went with the relatively forgiving 1084. I purchased a 1/4 inch, 4 foot length of stock from the NJ Steel Baron. I highly recommend him, as do many others in the knife making field.
Once the design was traced, I used an angle grinder to get the rough cut of the knife. The picture to the right is actually from my forge construction but you can see the leather gloves, leather apron, full face mask and hearing protection. What's missing from this photo is the 3M 6000 respirator. This gear lets you get close to what you are cutting without getting soot in your lungs and sparks in your skin. The Impact Sports hearing protection is nice because in addition to filtering out power tools / gunshots, it has an 1/8" jack on the back for listening to Pandora during the hour or so it'll take you.
For the rough cut the trick is to go slow enough you don't "burn" the steel and leave enough you can get in closer with slower methods like files and sandpaper.
Once I had the rough cut, I used a belt sander to make the bevels. To find the center line, clamp a drill bit of the same size (1/4 inch in this case), cover the edge of the blank with sharpie and scribe the tip of the bit along it. This will help you keep both sides even. If you don't have a belt sander, a file can do the job without too much trouble.
Heat treatment is the hardest part of knife making and breaks down into three parts. Annealing makes the metal homogenous so it's easier to work with; the metal from NJ Steel Baron comes annealed. The second step involves hardening where you rapidly cool the metal and make it brittle. The final step is tempering where it is slowly heated to make it tougher while retaining a certain amount of hardness. The video below (or downloaded from archive.org) from the Department of Education explain in more detail how this works.
First I heated my blank in the forge until the rare earth magnet no longer stuck (which is approximately the right temperature). I then quenched in used motor oil from my motorcycle. Do not use a plastic container to hold the oil because flare ups will melt the bucket. In the future I think I'll just rely on organic oils that are easier to dispose of.
Cashenblades.com outlines the tempering options specific to 1084 along with other alloys. This is a deep topic, but to summarize the higher the Rockwell hardness, the sharper and more fragile the blade is. For my process, I wrapped the hardened blade in tinfoil and heated to 500 degrees in a propane grill twice for one hour. I had trouble keeping the temperature constant but the final product performs so it does, in fact, seem like a forgiving alloy.
After this, the blade part is effectively done and the aesthetics are all that remains. Had I wanted brass pins for the wood handle, I would have drilled the holes before heat treatment. I opted for a smooth wooden handle, however, so I used 24 hour epoxy to affix cocobolo wooden slabs. Cocobolo is an interesting wood because it is incredibly dense and it takes patience to cut on the bandsaw.
After the epoxy has cured it's just a matter of shaping the wood and stepping to progressively finer sandpaper. This is a high-carbon steel knife, so be sure to keep a light coat of oil on it to avoid rust. In the future I'll be posting a write-up about the custom kydex sheath I made for it.