I had an afternoon off and some extra materials. Working from 11 A.M. to 7 P.M. I walked away with a decent knife. The original stack was going to be walnut-black spacer-beech-black spacer-walnut-brass, but I changed it to walnut-red spacer-black spacer-oak-black spacer-red spacer-walnut-brass. I didn't overwork myself or underwork myself and it was a very productive day. Give this a try and make one this evening. I'll show you how.
Step 1: Background and Materials
The Puukko is a Finnish knife design, it's made to be a well rounded knife with the exception of multiple blade styles and lengths. Some are made for carving specifically and some are made for skinning and survival. The design goes back around 1,000 years or more and has stayed a popular design. The design itself is plain, is without a handguard and the bevel runs the whole length of the blade.
Steel (I used rebar, but I checked the carbon content by grinding first. most carbon steel can be used)
Wood (hardwood is a must, a stacked handle can be made with multiple wood types)
Brass (I used a machine brass, its 1/4"x 7/8"x 12" and I cut a piece about an inch long)
Epoxy (general use epoxy or specialized wood/metal epoxy works)
Saw (hacksaw, bandsaw, reciprocating saw or a jig saw *must have a metal cutting blade*)
Tap and die set
Forging equipment (forge, tongs, anvil, hammers *swage block if needed*)
Files and rasps
Grinder (I used a 60 grit flap wheel, it removes metal fast)
Drill press (hand drill if no drill press is available)
Sandpaper (80, 120 and 220 grit)
Fine steel wool
Boiled linseed oil (vegetable oil can be used)
Sharpening stones (I use a 400 grit stone and a 600 grit stone)
Spacer material (plastic, bone, antler, brass, copper, leather)
Step 2: Forging
This step is pretty straight forward. You take your steel and shape it roughly, but I'll go into detail with a diagram.
(refer to PDF diagram)
1. Heat steel (rebar) to orange.
2. Flatten the end out to about 2 inches.
3. Start to hammer in the spine and curved edge.
4. Draw out blade, then cut about a half inch back.
5. Start to draw out the tang from the extra steel behind the blade.
6. Get the blade and tang straightened, measure the tang for handle measurements.
Step 3: Handle Prep
Start by measuring the tang to cut your wood the same length. It can be more tricky if you use a stacked handle with a lot of spacers and various wood. My handle ended up being around 4 inches or so.
1. Cut wood down to rough thickness.
2. Drill a hole all the way through the handle material long ways for the tang to go in. It shouldn't actually fit yet, it will be heat fitted later.
3. Cut in half to add other wood or spacers. I used thick Kydex and plastic for car bodies.
4. Make sure the stack will be the correct length.
Step 4: Grinding Work
This is the time to clean up the edges of the blade and tang. Try to make everything pretty level and squared up even if you need to use a file on the corners where the blade meets the tang. The bevel can also be shaped now. Depending on the job the knife will perform, you may want to have a different bevel angle. Do some research on your angle of choice. I make my bevel with an angle grinder by starting at the point and holding the same angle to the end of the blade or beginning of the tang. I used a file and rounded off the end of the tang for threading.
Step 5: Test Fit
You may now thread the tang end. This is a very slow process and can be messed up very quickly, so take your time. Cut a piece of brass the same size as your handle stack and drill a hole a little smaller than the threaded tang. You may now thread the brass piece and put away the tap and die set because it's so frustrating. Heat the tang and push the wood onto it, burning it in to fit snug. Now try fitting the pieces together and putting on the end cap.
Step 6: Heat Treating, Quenching, Tempering
People are easily confused by these terms and all steels require a different treating process. I simply heated the blade to forging heat, let it cool slowly in the coals, then reheated and quenched in oil. Afterward I heated it in the oven at 180 degrees F. for about an hour to remove some of the hardness. The blade held a pretty decent edge afterward and I did a bit of carving with it.
Step 7: Epoxy Time
Add all your stack pieces back together with epoxy in between and on the tang. Epoxy will run out from in between the layers and you screw on the brass piece. This needs to dry depending on the epoxy; some have rather quick set times and others need to dry and cure for 20-24 hours.
Step 8: Finishing the Handle
I used the grinder with the same flap wheel to start rounding the handle off and to shape the brass. I finished up with a file and the various sandpaper. The blade bevel can be sanded also to achieve a greater shine. I used steel wool to shine up the brass on the back and it became almost a mirror between the sanding and steel wool. At this point, the wood is very light and plain. Boiled linseed oil can now be applied in layers with some drying time and steel wool polishing in between. I usually do 3 coats the first day and one a week for a month or so. This will protect your handle and make it semi-water resistant.
Step 9: Sharpen
Start with your most coarse stone, using the same angle on both sides. Then use the most fine stone and oil (honing oil or 3n1) to create the final edge. You can also strop the blade to keep any small burrs from dulling your blade. I filed some grip onto the top of the blade and engraved the date of completion onto the spine also. Now you have a completely functional knife and if taken care of will last a lifetime.