Forging a knife

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My final week at the forge was a little short, since Arnon was sick for the first part of the week. Originally the plan was to make a pair of tongs to start, and then move onto the knife, but we decided to just skip the tongs and spend two days making a knife. The knife isn't completely finished yet because we decided it would be better to wait than to rush things, so I'll be going in on Monday to finish it

For the knife, I started out with a square bar of steel that Arnon picked out from his shelf. The steel is a really high carbon steel (somewhere between 1 and 1.5%, I believe he said), and it has some tungsten as well. It's a really nice steel; the tungsten allows for a little less precision in temperature when you heat treat it, although it also makes the steel tougher to work with. This steel was definitely the most difficult to forge of all the steels I've gotten to use.
For the shape of the knife, Arnon taught me how to make a "three finger knife", as he calls them. It's a small knife made from a single piece of steel, and it has a handle just long enough for three of your fingers. You use your remaining finger and thumb to hold the blade to get good control of your cuts. When Arnon made his example, he forged his so that the flat sides of the handle were parallel to the edges of the blade. When I started on mine, however, out of habit I forged the shape like a leaf, so that the facets of the handle are at a 45 degree angle with the blade. This is how Arnon normally makes his, and I hadn't even realized that I'd done it differently from his sample until he pointed it out. It made it a little harder to forge, since the handle was resting on a corner as I flattened the blade, but in the end it turned out nicely. The handle resting on a corner caused some gradual twisting as I forged the knife, but at the end I fixed the twisting by putting it in a vice and turning the bar with a wrench.
Once the shape was more or less finished, I cut the knife off of the rest of the bar using a chisel. Arnon then gave me a hammer he got in Japan that did a really nice job of smoothing out the surface of the blade. I annealed the knife (heated it up and let it cool off slowly), and then used a smaller flattening hammer to touch it up a little bit more while it was cold. The final step we did on Friday was to spread some black goop on the spine and blade of the knife. The goop is mortar meant for fireplaces, but it works well for our purpose, which is to insulate that part of the knife during heat treatment. The mortar takes a while to dry, so we figured that it would be better to let it completely dry over the weekend than to try and rush things. On Monday when I come in, we'll heat treat a batch of knives, mine included. For this kind of steel, we have to use oil rather than water (water will cool it too fast), and the oil needs to be preheated so that it's not too viscous.
I'm really happy with the way this project went; I had lots of fun, and Arnon and Nitzan have been kind and helpful. If I can I'd love to continue working with steel over the summer, whether that means finding a time I can help out Arnon, or even building a forge. It's amazing how versatile metal can be, combining both beauty and functionality, and it's pretty cool knowing that the things you make might last longer than your own lifetime.

If you want to see more pictures of the knife as I forged it, check out the Picasa album, where I have pictures of just about every step in the process of shaping the knife. I'll also put pictures of the finished knife once I get it tomorrow.


Can't wait to see the finished knife!

Thanks again for hosting Yoko and me on Friday. We had a great time! It would be wonderful if Arnon will keep you on this summer. And buidling your own forge? Cool!