Shaping the blade
Removing the Metal to get your final knife shape
At this point, you’ll have a pretty rough knife cut out. Now we have to begin refining the metal to its final shape.
Secure your blank in your vice on on your workbench with a clamp. Alternatively, using your recently drilled tang holes, you can actually screw your knife to the workbench and grind from there. Starting with your coarsest file, begin scraping away the metal all around the blank until you’ve reached your original outline. You may have to use a variety of files to helps with the tight spots and curved areas. You can also attach some coarse sandpaper to a dowel for those hard-to-reach areas.
If you used one of the hand-powered methods for cutting out your blank, the knife will likely have rough edges along its outer edge. Take a file along the outer edge of your knife and draw it flat, back and fourth, along the outside perimeter. This will create straight edges and remove those rough-cuts so you have a smooth final knife shape.
Be sure to remove the blank from your vice or workbench periodically and grip it in your hand to get a feel for how it holds in case you need to make adjustments along the way.
Grinding the Bevel
With the knife shape now refined and cleaned up, it’s time to grind the blade’s bevel and start giving it an edge. Not sure what type of grind you want? Have a quick look at my article all about knife grinds to see what’s best for your intended use. Now, we need to create a line of reference in the middle of the knife blade’s thickness for where the cutting edge will be. Start by coloring in the whole thickness of the blade with a coloured Sharpie or layout dye. Take a drill bit the same thickness as your knife blank, ie. 3/16″, and run it along the colored edge, point toward the metal, to scribe in a line. The point of the bit will etch a crisp line in the middle of your blade that you will use as a reference for the bevel—no matter the bevel, the two sides will meet at this point right in the middle to form the cutting edge.
I recommend here that you now coat your knife in layout fluid so that you can be sure you’ve grinded and sanded all parts of the blades later on.
After clamping it up again in your vice or attaching to your workbench with the blade out, begin filing from the cutting edge in toward the spine of the blade. Your file will only remove metal on the push, so lift it up as you draw it back. You’ll want to keep your file at a 22° angle or so (visualize cutting 45 degrees in half). Move around consistently and switch sides after several strokes. Take your time here and be more cautious than you think—grinding too low will require you to restart on a new edge. This process can be made much easier by using a jig to control your file’s movement and angle—great for beginners who don’t want to eyeball it yet. Aaron Gough came up with a great DIY approach that’s easy to make.
Continue this grinding process the whole way on both sides, always keeping on eye on the middle line that you scribed in. It’s a lot of work, to be sure, but once you’re done this step, you’ll have yourself a clean and consistent bevel on both sides.
A note about angles: the more acute your angle (say, 17°), the sharper it will be, but also more delicate—best for fillet knives and razors. And the higher your angle (say, 28°), the better suited it will be for heavy use—such as cutting rope or chopping wood. Somewhere in between those angles is the sweet spot for kitchen cutlery and hunting knives.
More experienced (or financially comfortable) knife makers will usually opt for power tool like a belt grinder to create their bevel. A 1 x 30 (1″ wide and 30″ long belt) or 2 x 72 is an expensive but effective machine that will help quickly remove the metal. Many creative knife makers rig up their own jigs to use on the grinder to make sure they maintain their desired angle.
For those looking to get a bit fancy, this is a good opportunity to use a round file or chainsaw file to create a decorative spine. Check this out—it’s called jimping:
Sanding the Blade
At this stage, we’ll be giving the blade an bit more of an edge before it goes in for a heat treat and hardens up. We’ll also take this time to sand down anything the needs to be finished more finely, like the spine or Ricasso.
TIP: duct tape the back of your sandpaper—it will prevent ripping and extend the life of it greatly.
Clamp your blade down flat onto your workbench (or something like what’s seen here), and wrap your 60 or 80-grit sandpaper around something like a wooden block or paint stick. Sandpaper is a lot harder to use without any backing. Aaron Gough actually has a tutorial on a DIY sanding block here. Starting with the bevel that you just filed down, begin sanding back and fourth diagonally in one direction across the blade. Once you’ve finished and made the metal smoother than before, flip the blade over and repeat on the other side.
After both sides are sanded with your coarse grit, switch to your next highest grit. Start sanding in the opposite direction and continue until the previous sanding marks are gone. Continue moving up in grits to get a finer finish and to remove any roughness from the lower grits. Go up to 220 or so, making sure that the previous sanding marks are not visible. Look at the blade from different angles as the light will sometimes hide sanding marks. We will do the final sanding and sharpening after the blade is heat treated and tempered.
Check the entire blade for anything you don’t like and make sure you fix it now—it’ll be much more difficult after the next step!