Introduction: How to Make Stylish Kiridashi/Utility Knife
I'm not a huge knife enthusiast but couple months ago I tried making my first knife. That was a very interesting and quite simple project. Having some spare time on a weekend I tought I should make try to make another one. I have had this design stuck to my head for a long time but I never got around to making it.
The design of the knife is inspired by japanese kiridashi knives but insted of having a very simple and straight handle I wanted to add some curves still keeping the design simple. I added a groove (not sure if it's called that) for the index finger which makes the handle more comfortable. Overall I think the handle turned out very comfortable and I might do a new version of the knife with better materials and slightly improved design. The knife works well as a marking knife of as a utility knife.
Step 1: Materials and Tools
Steel - I used only cheap 3 mm thick steel I had laying around but I recommend buying proper knife steel if you are not just practicing.
Wood - Also other types of handle materials could be used
Sand paper 60, 180, 400, 800 and 2000 grit
Finish for the handle - I used brown shoe polish! (Yes, it works)
Step 2: Shaping the Blade
First I traced my design on a peace of steel. First I cut the angle of the blade I wanted (as in the picture) with an angle grinder. Then I cut most of the extra material out as small triangles to save me the trouble of grinding all of the extra steel away. Then I used a concrete grinding disk I have (which is very effective in grinding steel) to shape the rough shape of the knife. Lastly I used a dremel with a small sanding drum to smooth out the edges still leaving a little room for last grinding which I will be doing after tha handle is attached.
Step 3: Sharpening the Blade
I used a compass to mark a straight line which I will be using as a guide while trying to get a straight bevel for the knife. I only made the bevel to one side only. This gives me sharper edge. At this point you should temper the edge of your knife if you are using a steel that can be tempered (here's a good instuructable on the subject). After grinding the shape of the edge I then sanded it with wet sand paper with grits 400 to 2000 trying to get the edge as sharp as possible and the blade as polished as possible.
I also sanded the area of the blade which will be covered with the handle with maybe 60 grit sand paper to give the epoxy some more surface area to attach to. This is especially important when you have a design without pins on the handle (like this one). If you polish the steel under the handle the epoxy might not stick to it and the wood will separate from the steel eventually.
Step 4: Shaping the Handle
I drew the rough shape of the handle on my handle material. Then I cut the silhouette shape out from the material. I split the handle material from the middle to get 2 identical scales for the knife. Then I used the dremel with the sanding drum to shape the handle I had designed. I constantly tested the how the handle felt in my hand to make the handle really fit my hand perfectly. I still left some extra material for minor adjustments after the handle was attached. I had to finish the shaping of front end at this point in order to prevent the dremel causing any scratches to the polished steel.
Step 5: Finishing the Handle
Next I used epoxy glue to attach the scales to the knife. Be careful when applying the epoxy to the fron part of the handle. You might run into some trouble if the epoxy is squeezed on the polished surface from under the scale when pressing the scale on it's place. It might be hard to clean up the epoxy. Because I used 5 minute epoxy I didn't have to use clamps to hold the scales down. I just kept them on their places by hand until the epoxy had hardedned enough. I used 5 minute epoxy but I let it dry over night because I have learned that the epoxy is still not completetly dry after a couple of hours. If the epoxy is not dry it will block your sanding paper and you might even accidentally rub the epoxy all over the surface of your project ruining it.
After gluing the scales on their places I finished shaping the handle with the dremel. This gave me smooth transition between the steel and the wooden parts. I finished the handle first by sanding it with 400 grit paper and then I used brown shoe polish to give the wood rich brown finish.
Shoe polish was an interesting experiment and it seems to work pretty well as a finish. Not only it gave the wood a nice color but it also gave it slight shine.
Step 6: Finished Product
Now the project is finished and its time to enjoy the finished product. Because I used a lot of thime in both designing the initial plans and shaping the actual handle it fits nearly perfectly in my hand. The curved handle also makes it more comfortable than most utility knives. Comfort is a key ingredient when you want to make really precise cuts. I recommend first drawinf a design based on these pictures and then cutting that out from cardboard to give you a rough idea how the handle fits in your hands. Then you can adjust the design according to your needs and make new models from cardboard until you think the handle fits your hand.
Thank you for taking time to read my instructable. Please, leave feedback and check out the build video!