How to Make a Harpoon on the Cheap

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Introduction: How to Make a Harpoon on the Cheap

Demonstrates how to make a harpoon, similar to the Hoffman Harpoon, intended as a sort of minimalist survival tool. It's 8 inches long, with a 2 and one half inch blade, the handle is wrapped in paracord.

I haven't made a sheath for it yet, but will post it when I do.

Step 1: Gather Materials and Tools

For this project you will need the following:

- paper.
- pencil.
- 8"x2" peice of metal.
(I used an old machete from walmart)
- saw to cut metal aka hacksaw.
- a couple metal files; flat, rounded, and 1/4" round file.
- sandpaper, grits 60 and up.
- glue.
- paracord, or whatever 1/8" cordage you've got lying around.
- vise (optional but helps a lot)
- drill (optional if you make a lanyard hole)
- honing stone (optional, but not if you want a sharp blade)

Step 2: Find a Helper

If you don't have a vise you can always get a puppy to help out, just make sure not to stick 'em with your new harpoon.

Step 3: Make a Template

Graph paper helps here, sketch out what you want the tool to look like, it's helpful to include a line indicating where the blade bevel will stop (I forgot to do that). Fot this one I made the blade at a 30degree angle to the handle, if I made another one I'd reduce that to 25 or 20 degrees. It is 8 inches over all, the blade is 2 1/2 inches long, the main part of the handle is about 1/2 an inch thick. The curve at the base of the blade serves a dual purpose of a hand grip and making a barb, ensuring whatever you stick won't come lose. Line up the flat edge of your blank and the template and glue the template onto the metal. Any glue will work but I used superglue so I wouldn't have to wait long for it to dry.

Step 4: Cut Out the Blank

Time to use the vise and hacksaw. There's a special purpose blade for cutting metal that's round, letting you change directions much easier than with the normal flat blade. In retrospect this would have made cutting a lot simpler.
To accomidate the blade I used I had to notch above the handle to create enough space to cut out the blank and then had to recut to get the thickness of the handle where I wanted it. Also when cutting the curves in the handle make sure to cut kerfs, being careful to stop just short of the edge, otherwise it requires a lot of filing to get rid of the gouge and may alter the shape you intended. Oh, and if you use a flat blade like I did you'll probablly have to rotate the blade occasionally so the frame of the saw isn't in the way.
An optional step is to drill a lanyard hole in the base.

Step 5: File and Sand

First file everything down to the lines on your template, making sure that all is smooth. Use care when filing the blade section to make it as flat as you can. About where your thumb will rest if your index finger is in the curve below the blade I make a few notches with a round file to improve grip when cutting. To start them make a very shallow cut with the hacksaw.
For the blade edge I made only one bevel, leaving the other side flat. Take into consideration which side you want the bevel on, especally if you're left-handed (make it on the opposite side I did).
Next sand off the paper, sand around the edges, sand the edges smooth, sand the file marks off the blade. Start with 60 grit paper, and work up to at least 220. The more care and higher grits you go to the better it will look in the end. You don't really need to worry about sanding off the black coating if you're using a walmart-machete; it'll help prevent rust by leaving as much on as possible but if you take care of it that won't be necessairy.

Step 6: Hone the Blade to a Knife-edge and Wrap Handle

To hone the blade use a shapening, or honing, stone. The blade should be fairly sharp after sanding but this will give it an even better edge. Follow the directions that came with your particular stone, mine came from Ace Hardware for about $10 and I have to use a light oil with it, some recommend water. Just make sure to hold it at the same angle you've filed and sanded, which should be 15 to 20 degrees. Because it's chisel-edged, insted of v-ground like a knife, sharpen it on the stone by placing the bevel down and drawing the blade toward you. Don't run it back and forth.

The only thing left to do now is to attach the cord on the handle. This is to make it easier and more comfortable to use as a cutting tool, and also to store the cord you'll need to attach it to a staff, making a true harpoon out of it. Ideally the cord is to be paracord, but if you can't run down to your local army surplus store, just about any 1/8" cordage will do.

To wrap the cord, first hold the ends together and find the middle. Place the harpoon on top of the middle of your cord. make an overhand knot, the same as the first step of tying your shoes. The way I do it the cord on the left will always go under, the cord on the right will always go over. If in doubt study the tying diagram. You can finish the wrap by tying a square knot on one side of the handle (two overhand knots on top of each other) or if there's enough cord, just go through the lanyard hole and make a knot on the other side of it. Tie the two ends together to make a loop.

Step 7: Use Your New Tool

I went out to a stream where there's usually clear shallow water so to demonstrate how to use the harpoon to catch a fish, but the rain from last night and this morning has made it as muddy as the mississippi. So not wasting an opportunity I cut a peice of a tire innertube to use (https://www.instructables.com/id/Comfortable-shoes%3a-How-to-make-shoe-insoles-from-i/) because my helper ate the insoles of my boots.

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    59 Discussions

    this is has to be the coolest intractable ever totally gonna make it

    Tried to kinda design the first 1 after the m48 harpoon

    Awesome instructable... Made one and still got enough material for another one. Gonna bang that one out tommorow. Probably gonna copy your pattern this time :P ...... Lol. Thx!!!

    13, 7:40 PM.jpg13, 7:40 PM.jpg13, 7:40 PM.jpg

    I have some old two man saw bladesthat work great for all kinds of bladed tools/weapons. As long as you don't go extremely long, they remain rigid enough. over greater lengths they will flex. However, they wont become bent under normal use. They also hold their edge faitly well under normal usage without tempering if you don't over heat them during creation process. if you do have your neighborhood welder heat treat them as suggested above. Here in IL the old used saw blades can be found pretty cheap usually at farm auctions.

    Hi Guys ! No need to cut up your machete. Just buy a wood plane blade. If you split it down the middle you can make 2 blades and it is a very good steel !

    A modded machete is a much better survival tool :P I'll link to the vid
    http://www.youtube.com/watch?v=IsZb_1XfFHo

    Ruby looks like a viszla mix. I've never seen one with more than just a tiny white spot on the chest, let alone that much. Still an awesome dog. I have a viszla named Elvis.

    2 replies

    you should write an instructable about how to make a pole to put it on so you could use it like a spear

    ''really cute pup & preaty cool harpoon!!!!!!!!!!!!!!!''

    You could have made it a bit easier on yourself by using a 1/16" metal drill bit and drilling multiple holes around the outline and then cutting it out. Granted, afterwards you have more grinding to clean up, but the cutting it out goes much quicker.

    OMG she is so cute! Good looking and healthy. I am a local vet at the Central Texas Animal Hospital. She looks like she is in good shape and not overweight. Cute doggy!

    1 reply

    It looks like it was designed to rip a man's guts out. I like it! Now you just need to sharpen the hell out of the leading edge so it will pierce deeply when thrown.

     very nice!! im going to make one next weekend along with a baby one with the leftovers, also do you know how thick the steel is?? i have a machete but i dont really want to cut it out, i have access to a lot of steel, but i need to kno whte thickness so i can buy a 10" by 2' piece to make multiple harpoons..
    thanks for the insructable 
    Trevor

     A nice sturdy alternative source to a machete blade would be an old, used lawnmower blade.