Introduction: Large Chef Knife With Black Walnut Handles
This is an entry in the
Epilog Challenge 9
In this instructable, I show how I made this chef knife. It's a big knife perfect for cutting in the kitchen. It has a classic and utilitarian design, made from O1 Tool Steel with a black walnut handle. This will probably be the longest Instructables / video I've done so far. I'm by no means an expert knife maker. In fact, this is only the second knife I've ever made so I am sure there are some things that can be done better!
For this project you will need;
Step 1: Steel
I started with a piece of O1 Tool Steel. There are quite a few different types of steel you can use to make knives. It's best you sit and spend some time working out what is best for your needs, what is most readily available in your country and what sort of heat treat setup you have.
O1 tool steel is known for being relatively easy to work with. I actually found a steel supplier about 20mins from where I live meaning I can go and have a look at it in the flesh before buying. The first knife I tried to make turned out well, but I used 4mm steel. It turns out this is a bit too thick, the knife was a bit too heavy and ends up pushing its way through food. I decided on 2mm for this knife and it feels perfect.
Heat Treat - One of O1's other main reasons for its popularity is, it is one of the easiest metals to heat treat without the need for a complicated setup. A lot of people recommend it for first-time knife makers.
I drew out my knife on the computer in Illustrator and printed it off. I made sure to include spaces for 4mm holes for the pins. I used some spray glue to stick the template directly onto the steel.
Step 2: Cut
Next, I put the steel in the bench vice and used an angle grinder to rough out the shape. I made sure not to get too close to the actual line itself as I was going to grind closer later. I used a thin 1mm cutting disc, and kept all the scrap bits that fell off to try and use in other projects.
The angle grinder does not leave a very smooth or clean finish. If I took this straight to the belt grinder it would end up ripping through the belts, and is generally pretty bad practice. So I took the steel over to the bench grinder with a grinding stone which is very aggressive does a great job of smoothing out the knife shape.
Step 3: Holes
The wood scales will later be held in place with some 2 part 5min epoxy. But in case that doesn't hold it's best to add some pins. Not only do they add a lot of strength and support, but they also look great. For this, I needed to drill some holes into the steel. If I didn't do it now (before the heat treat) then once the steel is hardened it would be too hard to get through. I knew I would be using some 4mm stainless steel rod so drilled 2, 4mm holes in the handle.
Step 4: The Grind
Back at the grinder, I put a fresh 30 grit belt on to start hogging out the bulk of the shape. I kept the knife on the table to ensure that all the edges of flat and level. I ground all the way down to the lines this time. By this point, the paper has normally fallen off, not the end of the world as I don't really need it anymore.
Using a sharpie pen I coloured in the edge of the blade. You can use any pen or get some proper metal scribing dye. But a sharpie works just fine. I made sure the full edge was covered in ink. The steel is 2mm thick, so I set the digital callipers to 1mm and marked a scribe line down the middle. I made sure to go from both sides which gave me two lines very close to each other, and right in the middle of them was the very middle.
I then started to grind in the bevels of the knife. I didn't want to go all the way edge yet. Once I had ground a good bit of the material out I was ready for the heat treat. You don't want to get the edge too thin else you might end up burning and ruining the steel.
Step 5: Heat
The fun part, where it can also go all wrong. The heat treat. First up, you will probably need some type of forge for this next step. Luckily there is a really great Instructables on here somewhere which can help ;)
So I took my knife and put it into the forge. I'm using a propane tank with a decent torch on. This does get the steel hot enough, but takes around 10mins or so. I kept moving the knife every now and then to make sure it didn't get too hot. I kept on heating the metal until it got to a red-hot all over. I tested the knife with a magnet to ensure it had lost its magnetism, when O1 tool steel gets to the right temp it is no longer magnetic.
Once at a red-hot all over I quenched the blade into some oil. I use vegetable oil here. There are loads of other types of oil you can use, some people use leftover motor oil, but I like to use vegetable oil. Firstly it doesn't smell too bad at the first quench, and then when tempering it, if like me you use your home oven, it won't smell too bad and you stand half a chance of not falling out with your wife!
After the quench, I cleaned off the excess oil that was left and tested the heat treat. The easiest way to do this is run a file along the edge. If the file 'skates' off the surface and doesn't bite at all you have hardened steel. If you're not sure run over another piece and you can feel and hear the difference.
Taking the knife back home I preheated the oven at 180° Celcius (350° Fahrenheit). I let the knife temper in the oven for 2 hours and let it cool down to room temperature in the oven. This step is super important, as before the temper the knife is very fragile and might smash if you drop it!
Step 6: The Return of the Grind
Back to the grinder. Now that is fully heat treated and we have some nice hardened and tempered steel it is time to put the almost final grind on. I started back on a 30 grit belt to remove the fire scale and worked all the way up to 800 grit silicone belt. I did all the grinding by hand as I find it easier to keep control of what bevels I was putting on.
After that, I moved to hand sanding with wet sandpaper. I kept going until near final finish.
Step 7: Scales
Not it was time to add the wooden scales. I am using a beautiful piece of black walnut wood for the handles. I cut it down to size and used some tape to hold the two bits of wood underneath the knife itself. This way when I drill I can use the holes in the knife as guides to drill the wood. I used a 4mm wood drill bit so the hole sizes all match up and fit the 4mm stainless steel pins.
I took the outside fronts of the scales, and sanded a 45° angle on to end. This will make a nice gradual slope from the handle to the blade.
Step 8: Pins + Glue
I took my 4mm stainless steel pins and used the dremel to cut them down to size. I was then left with the knife, 2 sides of wood, and 2 pins. I used some 2 part 5min epoxy to glue it all together. I laid down some parchment paper so any excess squeeze out of glue won't stick to everything.
I covered all the sections in the epoxy, clamped up and left for a few hours to fully cure.
Step 9: The Grind Strikes Back
So, back to the grinder? Yes. Back to the grinder. I taped up the blade as the knife was quite sharp by this point. I started on the 80grit to start shaping the wood. When working on the pins to get them flush to the wood, I was very careful not to overheat them, else this would ruin the epoxy.
I worked my way up to 600 grit so the wood was nice and smooth.
Step 10: Etch
I wanted to make this knife a bit more personal. So I electro-etched my maker mark into the steel. Electro-Etching is where you use some form of electricity etch something into the steel of the knife. I had some vinyl stencils of my mark made up and stuck one of these down to the face of the knife. I added a little duct tape around the edge of the stencil to ensure there was no bleed out.
I'm using a 12V car battery charger. The one end was clipped directly to the knife, and the other was wrapped in cloth that had been soaked in salt water. I held the end directly onto the knife and held it for around 3-4mins, moving every now and then to make sure it didn't overheat. After I while I could see that it had eaten in enough. You can keep going for much longer if you want a real deep etch, but I didn't want it to be too strong.
Step 11: Final Images
I did a final sharpen on the knife and added a coat of boiled linseed oil to the handle to bring out the colour and add some protection to the wood.
I'm really happy with how it came out. This is the first knife project I'm putting out, and will have a few more coming very soon!
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