Introduction: Kiridashi Marking Knife
I've been wanting to try my hand at making a knife so I decided to try making one out of a broken file. This is a Kiridashi style marking knife with a chisel grind. The handles are made of walnut and the pin is a nail that I cut in to a smaller piece.
Here is a video of the process.
First step was to anneal the file so that I would be able to work the metal. I heated it up to non-magnetic temperature (until a magnet didn't stick to it anymore) and then set it on a fire brick to air cool.
I drew out a basic shape using a marker. Then I used my angle grinder with a cut off wheel to trim off the excess. The last picture is the rough shape of the knife.
To clean up the rough shape I used my 1x30 belt sander fitted with a 80 grit belt. If the metal got too hot I would dip it in the water bucket to cool it down. This is pretty much standard operating procedure when grinding. After two belts and some file work on the inside corner I finished sanding and refining the shape.
Next it was time to grind the bevel, which I believe is called a chisel grind. This was touch and go as this was my first time. It came out okay but it needed some clean up, it was slightly rounded over. I used my file to flatten the bevel which helped dress up the blade, its not perfect but it was good enough. Filing is a re-occurring theme in knife making and lots and lots of sanding.
Next I measured and punched for the pin hole. I drilled the hole with my drill press.
Next it was time to heat treat the blade or harden it. I turned off some of the lights so that I could see the color change better. I got the blade up to non-magnetic temperature before quenching it. I quenched it in peanut oil. In the last image you can see the scale that builds up on the blade after quenching.
This is the blade after cleaning it up a bit after quenching. I wet sanded the rest of the blade with 320 grit to get all of the scale off. Cleaning off the scale helps you see the color change after tempering. Now it was ready for tempering.
I preheated the oven to 400 degrees Fahrenheit and then placed the blade on the middle rack and set a 1 hour timer. Once the timer was done I turned off the oven and let it cool down in the oven to just above room temperature or rather until I could handle it without having to use an oven mitt.
While the blade was tempering I cut the wood for the handles.
This is the blade after tempering. The camera doesn't pick up the color very well. I think it got slightly darker than it should have, which probably means my oven temperature isn't accurate, which is very common. So I will likely invest in an oven thermometer and figure out any adjustments I need to make for future projects. I'll have to see how the blade holds up.
Cleaned up the discoloration after tempering using various grits of sandpaper starting with 320 and working my way up to 800. I wet sanded both sides. I also made sure to refine the blade or cutting edge at this point. I didn't sharpen it but I did clean it up quite a bit.
I traced the handle shape on to the wood.
I didn't really have a plan for the handles so I kind of went along with whatever looked good or whatever I thought might looked good. The last picture shows the final basic shape. I decided later to trim more or rather sand more of the handles down to expose the metal. Again I was kind of "designing" on the fly.
Drilling out the pin holes for the handle. I just taped the handle to the blade and then drilled the hole. Same process was used for the other side. I also checked the pin fit. The pin I used was a nail, which is what I had available, in the future I will buy some stainless steel rods to use as pins.
I taped the two handles together using the pin in the middle to help stabilize them while I sanded them. Because of the shape I used for the handles it meant that I had to get the handles pretty close to finished dimensions before glue up. This was more challenging than I was expecting. But at this point I was committed to the look.
More handle refinement and more sanding...
I used Acetone to clean up all the surface that were to be glued. This takes off any grease or dirt that may be present.
I used 5 minute epoxy to glue on the handles and the pin.
When clamping everything together I had to make sure to clean up any excess epoxy because of the size and shape of the handles that I made. I used a paper towel that had some acetone on it. I tired to make sure to use minimal amounts of acetone so that it wouldn't adversely affect the epoxy curing. This was a little hard to do around the clamps but it actually worked well I didn't have to address any epoxy squeeze out after it had cured. Also in my excitement to glue everything together I forgot to mask off the blade with tape. This would have made clean up a little easier also.
After the epoxy cured.
Yup you guessed it more sanding and refining. I used the belt sander to clean up the spine and then used 320 grit to clean up the handles.
I sharpened the blade using 1000 grit up to 2000 grit then I used a piece of MDF with jeweler's compound on it to hone the blade and then a piece of leather as a strop.
Now it was time for the finish I cleaned off all the surfaces and then I applied 3 coats of Danish Tung oil to the handles.
Here is the finished piece. I learned quite a bit from this project which I hope to apply to my next knife. Thank you for reading, I hope you enjoyed this Instructable.