DIY Agate Knife!




About: I am a 15 year old student who lives in BC, Canada. I like making DIY projects that require skill and effort like building crazy bikes ( tall bikes, recumbent bikes, tandems), 3d printing, fishing, fish keep...

Last time I was in the lapidary club, I thought of making a knife out of a cool looking rock. As that was achievable, I got out my agate and started cutting out a shape of a kitchen knife. That proved to be successful, and motivated, I kept going on.

That day I had no idea I would make a knife, especially that I would make an instructable on it! Sorry I didn't have any pictures of the BLADE making proses. So in the next step I would briefly explain the BLADE making proses.

For this project you are going to need:

1) A rock with preferably 7-10 hardness (on the Mohs hardness scale) and pretty long (depending on how long you want it to be)

2) Scroll saw

3) A 100 grit grinding wheel; 200, 400 and 600 grit sanding BELTS (NOT GRINDING WHEELS); A polishing wheel and a polishing compound.

4) Epoxy or super glue

5) A piece of wood ((preferably hardwood (I used walnut)) for the handle

6) Dremel and a carving bit

7) Belt sander

8) A wet tile saw with a diamond tipped blade

9) Time and patience ;)

Step 1: Making the Blade!

So the first thing you are going to do, is to cut out the blade shape out of a pre-sliced rock on a wet tile saw with a diamond tipped blade. Check the rocks for any fractures, otherwise the vibration from the sanding machines will often make it break in two.

Then, make a rough slant of the blade toward a point. You want to make the slant from 1/3 of the total blade width, as this makes the blade stay sharp for a longer period of time.

Keep on going through 200, 400, 600 (if you have finer sanding belts, even better!) . Finish of by polishing the blade (and preferably the entire rock, as it will look even cooler in the end!).If there are still any bumps left, go to lower grit belts and redo the entire process back again, starting from the belt you just went on to.

IMPORTANT NOTE: The sanding discs (not rocks) have to be always watered to prevent the rock from overheating and cracking.

NOTE: Please always wash your hands before changing grit as it will prevent the coarser grit residue from contaminating higher grit belts.

And like that, you have a rock knife blade!

Step 2: Making the Handle!

Now it's time to make a handle! Draw whatever shape of knife handle you like (I preferred to use the same design as our kitchen knife), then measure the thickness of the blade using a ruler (so it is proportional in thickness to the handle) .

Cut out the desired shape. Then using a dremel, cut a rectangular hole for the blade IN the handle. Check if the blade fits, then do the final shaping on the belt sander (or with files and sandpaper). Dip a couple of times in sunflower or olive oil for final shine.

Pour the epoxy or superglue in the rectangular hole in the handle, and stick the blade in. Wait till the glue sets.

Step 3: And You Are Done;)

The final product can be used as a butter knife, as a decoration, or as rather rare gift!

Feel free to comment!

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Woodworking Contest 2017



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    8 Discussions


    2 years ago

    This is an awesome idea. Great job. The finished project is amazing. I got to try one. (Note, I'm also voting for you (and AGAINST myself) in this contest as that is a cool idea!

    1 reply

    2 years ago

    There were many stone blades. It is more traditional to use flint stones, though

    Alex 2Q

    2 years ago

    Nice idea for a letter opener!


    2 years ago

    I had no idea what agate was until now. Stunning work!

    Fuzzy Monkey

    2 years ago

    This is beautiful! Wow!