Firewood and Saw Blade Knife

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Introduction: Firewood and Saw Blade Knife

Trash to Treasure

This is an entry in the
Trash to Treasure

If you have a damaged saw blade, don't throw it away, turn them into useful knifes! There are many ways to go about it, but in this Instructable, I will present how you can make a simple hook knife. A hook knife is a specialized knife for carving bowls or spoons. The process is very simple and can be done in home work shop with a handful of tools. The same process can be followed to create a general purpose carving knife, just don't hook the blade. You can find more Hacks and Builds from me on my YouTube channel and on Hacknbuild.com.

Disclaimer: I am a hobbyist maker with no experience other than making a few saw blade and firewood knives for myself.

Materials Needed:

  • Damaged circular saw blade
  • A piece of hardwood firewood
  • Copper pipe or conduit for the ferrule
  • Epoxy

Metalworking Tools:

  • Angle Grinder
  • Metal Files
  • Tubing cuter or hack saw (optional)

Forging Tools

  • Map gas torch
  • Toaster oven or oven
  • Hammer

Woodworking Tools:

  • Hatchet, machete or large knife like a cleaver
  • Drill or drill press & drill bits
  • Mallet
  • Sharp chisels
  • Clamps

Safety Gear:

    • Eye protection
    • Ear protection

    Step 1: Draw Your Knife

    1. Start by sketching out your knife on a sheet of paper.
    2. Once you have a rough idea of what your knife will look like, you can determine the exact length of your blade.
    3. For the hook knife, I modeled the length of the blade using a slip of paper. I made my hook knife into a longer hook shape, which due to the length isn't very suitable for carving spoons. A shorter shape would give you the angle you need to carve the shallow bowl of a spoon.
    4. I made the tang (the part that sits inside the handle) as long as the cutting depth of my twist drill would allow for.
    5. You can create a 1:1 pattern in a vector drawing program. Inkscape is an open source vector graphics application and is excellent for this application. I am not that good at drawing this by hand, so Inkscape helps me to get the results I am looking for.

    Step 2: Cut Out the Blade

    Now it is time to cut out the knife blanks. I prefer to use a paper pattern glued on with some spray adhesive, but there is no reason why the pattern cannot be traced or drawn freehand.

    Apply Pattern

    1. Cut out your pattern that you made in the previous step.
    2. Apply spray ahesive
    3. Stick it on the saw blade

    Setup Work

    I find it works best and is most comfortable for me to cut a waist level with my arms close to my body. Get some scraps of wood and put them on top of the table to set your work piece high enough so that the grinding wheel does not penetrate the surface of your table.

    Cut Out Blade

    1. Put on you hearing and eye protection,
    2. Cut out the blade.

    Video link: Cutting the blade

    Step 3: Break Down Your Log

    You have a couple different options for breaking down your log. I've found splitting the log by hand to be the simplest and easiest way.

    1. Divide the log up into sections. Take your hatchet, machete or splitting froe and lightly tap across each section with a mallet until you have a grid that represents how you want to divide up your stock. You'll want to leave some extra material so the rough part of the lumber can be cut away.
    2. Continue splitting. If you only split partially, it may be easier to keep the log standing up while you continue your work.
    3. Square up your chunks. You can continue using your blade to rough-shape the stock to size. You can also use a chisel to take out material where needed.

    Step 4: Cut and Drill the Handles

    Cut and Mark

    1. Take your square stock and cut it to length.
    2. Mark an X on the end of the stock.
    3. Use a punch to mark where the hole will go.
    4. Use a small pair of dividers to scribe a circle on to the end of your stock that's the size of your ferrule. You could also simply trace around your ferrule.

    Drill Stock

    In my design, the tang is tapered so I used a few bits for the hole: an initial pilot bit, a narrower bit then a wider bit. At minimum, you will need to drill a pilot hole then drill your final hole.

    Step 5: Grind the Bevel

    You're now ready to grind your bevel. I used a belt grinder for this, but you could also use an angle grinder with a grinding wheel or flap disc. The bevel is only ground on the outside of the knife, so make sure to put the bevel on the side of the knife you prefer. Note: I am left handed!

    I created a guide 20 degree guide block to get a consistent bevel but this step can also be done free hand. The knife was tabled to the guide block using some masking tape. I worked my way up from 120-600 grit belts.

    Video Link: Grinding the bevel.

    Step 6: Shaping the Hook (Optional)

    If you've decided to make a hook knife rather than a carving or whittling knife you can start shaping the blade. This should be done hot, but you have a number of options on how to do it. You don't need a forge to do this per-set, but it helps to set some bricks around your torch to keep the heat in.

    Shaping the Blade

    I heated my blade up to bright orange, and then rounded the tip on the curved part of a steel block I am using for an anvil. This is a small blade and was done using very light taps. Another approach that might work would be to hammer it over a piece of steel pipe or round bar stock.

    Video link: Shaping the blade

    Step 7: Heat Treating (optional)

    A saw blade is already going to be hardened, so this step isn't really necessary if you've opted not to make your carving knife into a hook knife. For heat treating, followed a simple process based on my online research:

    1. Heat blade to cherry red
    2. Quench in vegetable oiI
    3. Temper in a toaster oven at 400F for 4 hours

    The heat of the blade and the tempering temperature depends on the type of steel you're using, but this approach worked for me.

    Step 8: Shape the Handle

    For shaping the handle, I used a chisel and a small carving knife. You can use other tools like a spoke shave or knife for this task. Make sure both your chisel and knife are as sharp as possible. I try to carve away from myself wherever possible.

    1. Make it round I started by taking down the corners so the stock so it's shaped like an octagon, then take each corner down so it's shaped like a 16-sided polygon (hexadecagon?) The point is, keep taking down the corners until you essentially end up with a round shape.
    2. The same process is repeated for the ferrule end. Use the outline as a guide. You can use a smaller knife here to aid

    Video link: Shaping the handle

    Step 9: Cut Ferrule

    1. Mark off a length of tubing. I left a little extra length since I would upset the ends of the pipe to add some character.
    2. If you're using a soft material like copper or aluminium, you can use a standard tubing cutter. If you are cutting conduit, use a hack saw or angle grinder.
    3. Add some character by upsetting and tapering with a hammer.

    Video link: Cutting ferrule

    Step 10: Cut Wedges

    The hole I drilled for the tang was quite large, so I used some small wood wedges to wedge the blade in place. The wedges were created from some left over scrap form the handles. These wedges can be easily split with a chisel and then carved to shape.

    Since I was going to glue everything together with epoxy, I didn't worry about getting them perfect.

    Step 11: Assemble Knife

    Now you have all the parts in place, it's time to assemble the knife! It might be possible to assemble the knife using only wedges, but I am not that good of a craftsman and I never plan on removing the blade.

    1. Mix up a small batch of epoxy
    2. Apply some epoxy to the outside of the handle where the ferrule will go
    3. Set the ferrule in place by tapping on the table. I also light tapped the back end of the handle with a mallet.
    4. Install the wedges
    5. Apply epoxy to the tang and install the blade. To set the blade, I carefully held the blade and and rapped on the end.

    Video link: Assemble knife

    Step 12: Finish and Enjoy

    1. Carve the final details into your knife.
    2. Apply finish: An oil based finish such as Danish oil or linseed oil is very suitable.
    3. Make something!

    Video link: Finish and enjoy

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      1 Questions

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      Can you heat the blade in a fire if you dont have a forge.

      I've had steel up red hot in a fireplace. I just had a bellows, not a blower.

      Yes, you can dig a trench and fill it with charcoal. You would need a blower to get the fire up to forging temperature. A hair dryer would work for that purpose. For this size of a project, the easiest way is to just use a map gas torch. They run about $40. You probably don't need to pile up bricks like I did, but it will help conserve gas.

      10 Comments

      Looks good! You are correct, the blade is too long. If you want one to reach the bottom of a kuksa or bowl, you should make the handle longer. Then you can apply leverage.

      Thanks Capn'. The construction process I used worked well for me, and I think I'll make some more. My next one will be closer to a question mark shape. Have any other ideas on a shape that would be good to have?

      The bevel should definitely be on the outside. I've tried to find video of the long handled spoon knives, but wasn't really successful. It's long enough to fit under your arm, and gives you leverage to put some power behind digging the meat out. Afterwards you should use a smaller spoon knife to do the detail. If you can get the right edge on one, it should be sharp enough to cut across the grain. Cutting with the grain is for finishing, and you can use a cabinet scraper to fine the finish on a spoon; sandpaper just seems to make the surface fuzzy after it gets wet and the grain rises. Best woods for carving wood bowls, cups, etc. are fruit woods, Apple, Lemon, Pear. Pear so far is the best for me. Oils should be food grade, Flax oil, or Tung, Walnut is good, but can be bad for allergies, so it's easier to not use it. These woods are fine grained, and can be extremely hard, so are best carved while still green and left in a box of sawdust to cure out without checking, which cherry is very ready to do.

      I know you're just asking about shape, but the wood you would carve with it also determines the shape of the tool...

      Great information, thank you. I plan on making another couple of knives and I''ll definitely keep these suggestions in mind.

      A fine tutorial. I have made a few cutting tools from circular saw blades. I always tried to get saw blades where the teeth were fashioned from the blade- not added on carbide teeth. That way you are guaranteed the saw blade is good tool steel.

      Thanks! I agree, using solid steel blades is probably the best bet. These blades are worn out cold-cutting blades. I made some other carving knives before this one and seem to hold an edge pretty well but I don't have a whole lot of other carving tools to compare it to.

      This turned out very nice, thanks for sharing!

      Very nice! I've wanted one of these forever. Somehow never even crossed my mind to forge one. Brilliant mate, I think I'll have to do this sometime.

      Thanks Jake. It is a pretty easy project, anyone can make one. If you don't have any saw blade material I bet you could use an old kitchen knife or similar.