Introduction: How to Make a Harpoon on the Cheap

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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 ( because my helper ate the insoles of my boots.


hleeper1 (author)2017-09-14

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

ilacoppola (author)2013-05-11

Tried to kinda design the first 1 after the m48 harpoon

ilacoppola (author)2013-05-11

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!!!

BigBear575 (author)2013-01-17

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.

Wulf187 (author)2012-05-21

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 !

doughnutguy1 (author)2011-07-28

A modded machete is a much better survival tool :P I'll link to the vid

Belcher1035 (author)2008-05-08

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.

Did he sing? xD

Cool. Ya, she's a mix, I think it's with a beagle.

shadow wave rider (author)2011-06-24

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

MMoyce (author)2011-05-21

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

cudubh (author)2011-05-05

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.

supershot1 (author)2011-04-08

you have the same drill press as me

zach911 (author)2008-06-01

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!

supershot1 (author)zach9112011-04-08

in odessa???

supershot1 (author)2011-04-08

"Excuse me, but wtf are you doin?"

Toxonic0 (author)2010-12-17

Nice quadruple post.

xarlock667 (author)2010-10-20

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.

eyepodd (author)2010-05-29

 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 

Jungle Jodo (author)2010-05-05

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

XkidXhavocX (author)2010-04-26

would a gear off of an old go cart work? im not positive on the type of metal these gears are made of.. should be some type of high carbon steel, right?

red anger (author)2009-07-10

trust me, after you have had a wal-mart (ozark trail) machete you may want to trade that particular machete for anything.

travisttt (author)red anger2010-03-24

This is very true. DO NOT RELY ON A CHEAP BLADE YOU HAVE NOT TESTED FOR SURVIVAL! I bought a "survival" knife from big5 once for $20. Broke the first time it was really used. The separate blade might just become a harpoon on the cheap.

GameV8 (author)2008-05-09

Anyone know how this kind of "Barbed Bladed Tool" is handled in California law? I already know that there is no real length limit for a fixed blade as long as it is "Open Carry" . Pictured:

I don't know about that specific item but here is a site where you can find California (and other states) laws on knives.

This is a useful resource.
Thank you very much.

This one might also interest you.

This organization is of GREAT interest to me.

It is my firm belief that knives are essentially the only thing standing between humanity and the bottom of the food chain and that the ownership and carrying of knives of any shape, size, or mechanism, should not be restricted by the law.

Thank you once again.

Murphman (author)2008-05-11

Sorry for the second post, but is there an alternative to a machete? If so, what is it?

notjustsomeone (author)Murphman2008-05-12

If you want to avoid heat treating metal, anything under 3/32 of an inch will do, the more rigid the better. If you don't mind heat treating steel almost anything will do. A good, simple introduction on how to do this can be foune here:draw knife. Using this method you could "recycle" an old file, lawnmower blade, steel plate, flat pry-par, that stupid metal art thing your wife bought, ruined wrenches, just about any peice of scrap steel you can find. hope this saves you a trip out.

the link is dead

Murphman (author)notjustsomeone2008-05-13

Thanks very much, I have had two old lawnmower blades sitting in the garage for a while now. Perfect.

builder210 (author)2008-08-11

Very creative... although I wouldn't trade my machete for a harpoon

Agreed you can make a decent fishing spear head from fire hardened wood or bone. A machete however is a valuable tool which cannot be duplicated easily in the wild.

Murphman (author)2008-05-11

Nice! Just one thing; I have not actually checked yet, but do Walmarts carry machetes in Massachusetts? If someone knows and could let me know, that would be awesome, before I make the long haul out to one? Otherwise, This looks amazing. First on my list of things to make.

I know lowes does i dunno if that is how you spell lows but anyway lowes home improvement has them

i remember how to spell it by the commercial where it says "Lowest" they just added the T in a creative way. So it just Lowes

trike road poet (author)2009-09-25

Instead of using the cheapo steel of the wal-mart machete, consider stopping at any quality hardware or materiel supply house and buy some of the high quality steel strapping, (some running up to quarter inch thick and 2 " wide. Easier to cut and easier to sharpen.) Once you have it cut to size and shaped the rough cutting edge angles, take it to any competent welder in the area and they can simply use a torch to heat the steel EVENLY to a dull red to cherry red (930 to 1,075 degrees) and quickly quench it in simple water to temper the blade for a good edge holding ability, and still have a good toughness to resist bending in use. The strap material runs a few bucks (Less then $3-4), and I found a welder who charged me $5 for the quick heat treat. For less then ten bucks I had a blade that could hold an edge, was strong enough to prevent bending and as a fun side, I later heated the blade in the kitchen oven to 150 degrees for five minutes and then coated it with black oxide treatment as used for guns. The finished product was now great looking, and weather resistant. Add in a nice grip wrap with OD green para cord and it looked sweet. I had it maybe an hour before my brother saw it and bought it off me for $25! Now I'm considering doing a large and small blade set and make a combo sheath and see which of my buddies just can't do without one. Use good steel for your blades, cheap steel is cheap for a reason, and you don't want to have to count on something cheap when its your life on the line one day.

SkateboardingForLife (author)2009-06-19

this is nicely made im gonna try to make one similar, but ive got another idea of putting blades into a monkey fist knot

jacobzman (author)2009-05-06

fishing tool

j626no (author)2009-02-17

how many hours would you say this took from start to finish? i was thinking about doing it this weekend but idk if i'll have the time. thanks.

notjustsomeone (author)j626no2009-02-17

Realistically, with careful work and attention to detail, there's no reason it should take more than five hours from the initial drawing to having it razor sharp and ready to use. I can say though that a decient job of it can be made within two hours if you're pressed for time, if nothing else cut out the blank and leave the blade for when you have the time to shape and sharpen it properly.

j626no (author)notjustsomeone2009-02-18

alright, that works. I'll pick up a machete this weekend and get cutting! thanks

chuck123456789 (author)2009-02-14


dodo101 (author)2008-10-24

Thank you SO much ! since the day I saw the original Hoffman Harpoon, I really wanted to get one, but the price was just a little too much... until the day I found your instructable ! :D

I tried to make it the same way as you did, except that I used another angle for the blade and I repainted it just to add some 'protection' to the steel.
I also wrapped the handle with some electrical tape to make it a little thinker and also so that the paracord wouldn't be in contact with metal.
And I also made a baby-harpoon with a leftover from the cutout...

it was the first time a made a blade and I really (REALLY!) enjoyed it !
thank you very much (again!).

Kryptonite (author)2008-10-02

Very nice! could you post how to use it as a harpoon though? I'm guessing you could cut a slit through the middle of a broom handle and epoxy it inside, with 2" - 3" poking out of the end. Well executed 'able and very nice harpoon, seriusly it looks as tho it was made by a proffessional.

NO, NO, NO. You never cut a slit, who carries around a broom handle, and epoxy is never the answer...ever. First we'll assume you're at least in a wooded area if not wilderness, rather than just trying to stick your annoying little neighbour with a spoon epoxied to a broom handle. Now then, the first task is to find a suitable sapling or branch from which to fashion the shaft of your harpoon. Suitable is a very liberal term so here are a couple "rules of thumb": straight is good not necessairy, saplings are better than dead branches, the shaft should be around 8 feet in length and 1 inch in diameter. If you have absolutely no imagination and didn't bother to bring anything else with you can cut the sappling down at the base by placing the blade of the harpoon on the tree and hitting the back with a rock, in essence chopping it. Once liberated from the ground you'll want to get rid of any little branches and most likely snap or cut off the top of the sappling before it gets too thin to be of use. Once this is done use the harpoon blade to make a groove in one side of the tip suficiently flat and deep enough that the harpoon can rest in it without chance of the base slipping down the shaft and so that at least three inches of the harpoon extends from the shaft. Now unwrap the paracord from the harpoon "handle" and use it to lash the harpoon to the shaft you created. If you've thought ahead or just have extra cord lying around, it's a good idea to tie one end through the lanyard hole in the harpoon and to make a loop in the other to secure around your wrist, just in case. When fishing in a river the best areas are shady pools on the inside of bends, remember to move slowly and always approach from downstream. I went out today to try and demonstrate this but didn't have any luck, lesson learned is leave pets that like to swim at home.

Hmmm... one thing, if you do spear a fish you want the harpoon to go out through the other side, so that when you do get it you can pic it up, because the harpoon will be caught on the other side of the fish. With the way that yours is set up catching a largish fish would be difficult, because the spear would go in, then when you yank the fishes internals will be shredded, and you won't pick up the fish. I was thinking of a smooth shaft so that could go through the fish as well. The way you currently have it set up you will have trouble catching anything larger than 3 inches wide. And epoxy is not "never the answer," it's quite good for glueing your step brothers for finger and thumb together.

wolfy_9005 (author)2008-09-28

She's like "wtf??" Im gonna guess she's ~3-4 years old

in this picture she's somewhere around 5 months. she's at least 3 times that size now.

About This Instructable




More by notjustsomeone:Hand Guard for a SwordHomemade Lens CapThe Box Kite
Add instructable to: