Saw Blade Knife
by danthemakerman in Workshop > Metalworking
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Saw Blade Knife
A buddy of mine and fellow YouTuber wanted to do a collaboration video. We bounced around some ideas and eventually decided to film ourselves making knives. The catch was that I would do it by hand (except for a drill and oven) and he would do it using power tools. We both started off with the same blade design, same steel, but the rest of the design aesthetic was left to us. I also wanted to do this because I have read on many occasions all you need to make a knife are some files and a drill or something to that effect. I was curious as to how long it would take me to make a knife by hand and to see if I could do it without cheating and using my power tools. So I figured this was the perfect opportunity to try it out. This was a fun build that took a lot longer than I expected and gave my a whole new appreciation for people that make knives entirely by hand. Overall I am very happy with how the knife turned out and I hope this helps anyone out there that wants to give it a try.
Video link of the whole process.
I tried to maximize the size of the knife by using a design that used as much of the saw blade as possible. I made a paper template using card stock which is just a heavier weight paper so that I could more easily trace the paper template on to the saw blade. I used a fine tipped marker, while this is a small detail in my opinion it is an important one. The fine tip marker leaves a thinner line to cut or file too as opposed to a regular tipped marker. The cut line can become ambiguous if its too wide which can affect the overall shape and lead to irregularities in the shape and more issues to address down the road.
With the sawblade clamped to a work table I began by cutting out the rough shape of the blade using straight line cuts. If you have never used a hacksaw before make sure to secure the blade on correctly, the teeth direction should face forward or away from your body. The saw cuts on the push stroke so make sure to install the blade correctly.
In order to cut away the curved section of the handle I made several perpendicular relief cuts along the entire length of the curved section of the handle. Then using the hacksaw at a slight angle I would cut out each small section. The relief cuts make it easier to follow the curve as you cut.
I needed to refine the shape of the blade so I attached a scrap piece of 2x4 to my work table and clamped the blade to the 2x4. This allowed me to work the shape with my file while the blade was nice and secure. I also used the file to gauge which areas needed more work. The design of the spine had a slight curve to it and I could use the flat part of the file to check the progress on the curve. If the spine had a flat spot the file would make it obvious.
I used several files to get the shape just right or as close as I could to the marker line. At this point it is starting to look more like a knife and flaws are harder to spot by eye. If I spotted an area that needed work I would use a marker re-draw the shape and then file to that new marker line. It served as a guide so I wouldn't over correct and ruin the design. The last picture is of the blade after it has been filed and sanded down to shape. I don't have any photos of me sanding the blade, this is the last step to shaping which cleans up any file marks. I would start with 150 grit and work my way up to 220.
Initially I planned to have a plunge line with a nice high bevel but my limited skills were not up to the challenge. Saw blades are fairly thin material and I didn't think I could file the blade to achieve the plunge line and bevel I was after. More on this topic later. At this point I also measured out the pin placement and center punched and then drilled the holes with my cordless drill.
Using a marker I marked the entire length of the blade. Then using a drill bit with the same thickness as the blade I scored a line down the center of the blade. The last picture shows the line it doesn't show up well in the picture but it is there. This line will come in handy when filing the blade bevel, it will keep me from making a crooked or lopsided edge.
I used a bastard file to define the bevel this is where I realized that I didn't have the skill to make a nice plunge line by hand. So I opted for a more gradual angle and filed the blade working my way up from the edge to the spine. I am new at this and inexperienced so I chose a more conservative route in terms of stock removal. Once I was happy with the bevel I sanded the entire blade up to 220 grit.
Here is the blade after all the shaping, filing and sanding ready for heat treat.
Before I go on I would like to say that while you can heat treat a blade with an open wood fire I personally don't recommend it. This is one of the times that I really didn't feel safe performing an action. And I wasn't sure of the heat treat took so I did end up using my mini forge (here's my Instructable on how I made my mini forge https://www.instructables.com/id/How-to-Make-a-Mini-Forge/) to heat treat the blade instead. If you don't have a mini forge you can actually send your blades off to have them heat treated. There are several companies that offer this service for a fee of course. With that said I will explain my set up. I built a wood fire. Then using a hair dryer with a pipe attached to it to act as the bellows I turn on the hair dryer and got the coals red hot. This didn't take very long. I put the blade in the fire and let it heat up until it was no longer magnetic and then quenched it in a container of peanut oil. The last pic shows what the blade looks like after quenching. While it is possible to heat treat on an open flame I don't recommend it.
Now it was time to temper the blade but first I sanded off all of the scale from the quench. Then in my oven I set the temperature to 375 degrees Fahrenheit (in my oven setting it to 375 degrees Fahrenheit will reach the 400 degree Fahrenheit mark I suggest testing your oven to see what temperature to set it at so that it reaches 400 degrees Fahrenheit) and placed the blade in the oven for 1 hour. At the end of 1 hour I turned off the oven and let the blade cool inside with the oven door closed until it was cool enough to handle. You can see the blonde-ish or light bronze-ish color that the blade turns after tempering. After the temper I sanded the blade to clean it up using 220 grit and working my way up to 400 grit. In the last pic I am using a wooden block with 400 grit sand paper wrapped around it and sanding from the handle to the blade tip in one direction only. This leaves uniform sanding lines on the blade.
Using the blade as a template I trace the handle shape on to the wood. This piece of walnut was given to me by one of my neighbors it was a cut off piece that he had milled down. Here again using my 2x4 scrap piece and clamps I sawed two 1/4 thick pieces off. In my excitement I rushed in to cutting the wood, had I taken some time to think about my order of operations I could have done this more easily and probably with better results. My first mistake was cutting off the waste material. I could have used this material for clamping the piece down and then cut out the two handles. Here again my inexperience, in this case with hand tools, rears its ugly head. I did manage to get two useable handle pieces but I'm pretty sure I worked a lot harder than smarter to make them.
In order for the handles to be epoxied to the blade with a snug fit I made sure to sand one side of each handle as flat as possible using a flat surface and sandpaper. This will ensure that there are no gaps after glueing. At this point I also decided what the handle shape will be and drew a reference line on the blade to make sure I liked the look. Then I traced the blade handle on to the wood again. Using a coping saw I rough out the shape on one handle and then take that handle and trace it on to the other handle. Doing so will ensure that they are roughly the same shape which will come in handy when glueing on the handles. The last pic is a test fit to make sure they cover all of the tang.
Time for more sanding and shape refining. It is important at this point to finalize the shape of the bolster section or rather the top of the handles because once it is glued to the blade it will not be easily accessible. And any further work on that section after glueing may result in scratches on the blade. So I sanded up to 800 grit sandpaper and made sure that particular section was finished in terms of sanding and shaping.
When drilling the holes for the pins through the wood I made sure once the first hole was drilled that I used a drill bit, of the same diameter as the hole, to index that hole. In other words this keeps the blade from moving or misaligning when drilling the other hole. I used the same indexing process for the opposite side to make sure all of the holes would line up when inserting the pins.
I used 3/16 inch stainless steel pins that I cut from a stainless steel rod. Before glue up mask off the blade and clean everything with acetone or alcohol to remove any dirt, dust or oil.
After everything had dried from the cleaning. I mixed up the epoxy and slathered on a generous amount on to the handles and pins. Then I clamped everything together and let it cure for 24 hours.
Once the epoxy had cured I cut off the excess pins with a hacksaw. Then using a rasp began to shape and contour the handle.
The rasp got me to the rough shape now it was a matter of using various files and different grits of sandpaper to shape the handles. I worked my way through the various grits of sandpaper up to 600 grit.
After a ton of sanding I was finally happy with the shape and feel. I used some acetone to clean off the handles before applying the finish. I applied 5 coats Danish tongue oil to the handles.
Lastly I sharpened the blade using my sanding block. The sanding block has 1000 grit, 1500 grit and 2000 grit sandpaper taped to it. It also has a piece of leather that serves as a strop. Using this sanding block I can get the knife sharp enough to shave hair.
The finished knife. While this was very challenging it was very rewarding. As someone who is starting off on their journey in knife making I felt as if this was a rite of passage. The process of making a knife is a transformative one. This transformation process is my favorite part of the experience. Not only do I transform one thing in to another I feel as though I am partially transformed as well. I acquire new skills and know how and learn from my mistakes which I think will ultimately make me a better craftsman. I hope that you all find this Instructable helpful and thank you for taking the time to read all of this.
Bonus Content
I also made two other knives one for myself and one for my buddy Howie from the "July with Fitz" YouTube channel https://www.youtube.com/channel/UC2mSVc3U6F-fOK5ktmbCaiA whom I did the collaboration with. These other two I did not make by hand I used my power tools and they probably took my about a third of the time to make as the hand made one. The one with Maple handles and brass pins is Howie's and the one with Mesquite handles and steel pins is mine. The last pic is of all the knives together.