Here is how I used fire to help me shape and build a knife from a file. While I used many power tools the only one that I found essential was the drill while the angle grinder and sander could have been replaced by files.
Step 1: Tools Required
For this project I used the following things:
- piece of high carbon steel which will become your knife (I used a file for this)
- forge or BBQ
- belt sander (not necessary but saves time)
- angle grinder
- metal rod or nails
- wood bone or other handle materials
- a short section of PVC pipe
- black spray paint and clear coat
- files and rasps
- a drill
- a dremel or rotary tool is also useful
Step 2: Annealing the Metal
Due to how hard files are they require annealing in order to make them soft enough to be worked by most tools, in order to do this I placed the entire file into a charcoal BBQ which I used to heat it until it was red hot. I then allowed it to cool slowly outside of the BBQ softening it enough for my tools. However this process can be repeated in order to soften the metal further and make it easier to work with.
Step 3: Shaping
In order to shape this file into a knife I first used a hack saw to remove the tang of the file and then used an angle grinder with a grinding wheel, and ground the file to a shape which I had drawn onto it. I then tidied up the shape with a one inch belt sander, and began to add a bevel to it. However when adding the bevel it is important to measure and make sure that you grind on both sides down to a mid point marked on the edge in order to keep the blade straight. This can be done by taking a drill bit the same thickness as the piece of metal which you are using and scratching a line down the edge of the piece of metal which should be in the centre, then grind to this line. It is also important to drill three holes through the handle at this point while the metal is still soft, make sure the holes are the correct size so that the metal rod or nails that you are using as pins will just fit through.
Step 4: Further Shaping and Heat Treating
I used my homemade forge as well as a pair of pliers and a hammer to make the blade slightly wider and add a slight curve to it. I then placed the blade into the forge until it became non magnet at which point I removed it using pliers checked that it was straight and dunked it into vegetable oil in order to harden it (different oils affect the steel differently so depending on what you want to use your knife for this should be researched).
A simple forge only requires a metal base and some kind of air blower and as such they can be fairly easily built.
Step 5: Tempering
In order to temper the knife I first removed the scale from it and then placed it into the oven at 300 degrees Celsius for two hours, until the steel turned a wheat colour.
Step 6: The Handle
A knife's handle must be comfortable for the user, and part of the fun of making your own knife is that you can make the handle a perfect fit for your hand. For my handle I used Beech wood, cow bone and some red plastic from a celebrations tub. I began by cutting my materials to length using saws (and the angle grinder for the bone, make sure to wear a respirator) and using two part epoxy to secure them to a piece of red plastic, I then repeated this, I then used epoxy to glue the first side of the handle on and then used a drill to continue the holes that I had drilled through the knife handle earlier. I then glued the other side of the handle on and continued the holes through that (when drilling through bone I made sure to use a HSS drillbit). I then cut longer lengths than I needed of my metal rods, coated them with epoxy and used a hammer to tap them through the holes, leaving excess rod on both sides I then trimmed it down slightly and used the round end of a hammer to gently peen down the rod ensuring that the handle was secured in place. I then used a combination of rasps files and sandpaper to shape the handle (as well as a flappy sanding wheel on the angle grinder). I then used needle files in order to cut lines into the bone (which I had planned to scrimshaw). I then masked off the rest of the handle and gave just the bone a single coat of black gloss spray paint and instead of sanding it of to just leave it in the grooves I decided that I liked the way it looked and left it.
Step 7: Making a Guard
While my handle was good it was not impossible for the users hand to slip up on to the blade, in order to prevent this I decided to add a guard. While I tried making metal ones I didn't like the way that any of them turned out so I decided to make one from PVC pipe which is light strong and flexible. To do this I took a piece of pipe and sawed through one side. I then heated it over a hob until it was flexible and used its natural curve to create a shape which I liked. I then drew on my design and cut it out and used a Dremel to cut a slot in the centre (although this could be done with a drill and files). I then sanded the piece down and spray painted it matte black after it had dried I fitted onto the blade and secured it in place with super glue.
Step 8: Finishing Touches
I sanded the whole thing particularly the handle as I wanted to draw out the grain of the wood and leave the blade looking rugged. I then applied four coats of olive oil to the wood on the handle and sealed it with clear coat.
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