Homemade (Waterproof) Fuse, for Homemade Fireworks




About: I'm an experimentalist, a scientist and I have a tendency to do things just for the sake of doing them, or to find out what they're like. I love life, show me something I can feel good about. I've got an ...

It's simple, it's effective, it's waterproof.
This Instructable is for people who are playing with chemicals and making their own pyrotechnic devices.

The short video shows the fuse burning and nothing more.
The long video show exactly the same clip and three others with titles.


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Step 1: Materials

The essentials:

Cotton string.
Inorganic oxidising agent*

Polyethylene (HDPE) milk bottle (or similar)
A knife or scissors
A mortar & pestle
Ink/dye (optional)

*If you're making fireworks you'll have some, e.g. KNO3.
Back then I could get sodium-chlorate weed-killer (it's broad-spectrum) where ~50% was just salt. You put it through a sive and the big-lumps are what you want.
Last time I bougts some the salt was caked onto the lumps like Nerds etc,,

Step 2: Funnel

The method is to coat string in a ferocious pyrotechinc mixture, made from glue and oxidiser.
In order to get a nice even coating a funnel device is used, made from a piece of HDPE.

>Wash a HDPE bottle.
>Cut the bottle to extract a flat sheet.
>Save the bottom of the bottle for mixing glue.
>Dry the pieces of HDPE that you will use.
>Curl the flat sheet into a tight cone, the hole at the tip should be only slightly larger than the diameter of the string ~0.1mm.
>Secure with tape
>Thread a piece of string through the hole (sucking usually works)

Step 3: Coating

The glue you use will make a difference, I use 2-part epoxy and it is by far the best that I've found so far.

>Grind the oxidiser to a fine powder using a mortat & pestle (or improvise something else).
>Mix two part epoxy, as manufaturer's instructions (add colour at this stage if you have any).
>Gradually work powdered oxidiser into the epoxy until you have a thick sticky paste.
Too little powder will give a slower, cooler, sootier flame.
Too much powder and the mixture will not stick well to the sring.
Aim to have the mixture looking 'wet' but load as much powder into it before it becomes 'lumpy' and 'dry' looking.

>Add the paste to the funnel.
>Tie the string to something solid, or hold it with your fingers.
>Gently pull the cone of glue along the string, rotating as you go.
This should give you an even coat of mixture until the paste is used up.
>Hang the fuse out to dry (~30 min is enough with epoxy)
>When the fuse is just dry, wrap aroung e.g. a beer-can and leave to fully harden.

>Trim your ends, and you can remove the reside from the cone for burning later (see video)

Step 4: Testing

Cut short sections of fuse and light them at arm's length, preferably with something that doesn't involve getting your hand too close.
Dip a section in water and try again.

(As the previous step)
Slow sooty flame: too little powder, damp powder.
Good flame but doesn't burn smoothly: Uneven coating, maybe due to too much powder, the dimensions of the cone, or pulling technique.

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    199 Discussions


    3 years ago

    If I use the potassium nitrate and sugar formular to make fuses is the only thing I need to do is coat it with the epoxy to make it water resistant?

    1 reply

    Reply 8 months ago

    I'm not quite sure, but it might work. In this fuse though, the epoxy acts as the fuel too. It sure wouldn't hurt to try!


    3 years ago

    That didnt work for me at all, the fuse lights up for a fraction of a second and then goes off.....


    Reply 9 years ago on Introduction

    They make ANFO explosive. With Ammonium Nitrate as the oxidizer and fuel oil as the "fuel", I don't see why it wouldn't work. I could be wrong though.


    Reply 3 years ago

    Amonia nitrate is used to make tannerite. It is very flamable when mixed with aluminum powder.


    Reply 9 years ago on Introduction

    actually the ammonium nitrate is both the oxidizer and the fuel, secondary high explosives by definition contain both the ox and fuel in one molecule. anfo is sometimes called a binary but its not a binary like astrolite or tannerite. the fuel oil is just there because ammonium nitrate gives out a surplus of oxygen which can be used to burn the fuel oil. it doesn't act like a thermobaric because the oil is soaked into the nitrate therefore can't be dispersed. won't work for a fuse, stuff is hard to get burning at the best of times due to its very hygroscopic nature. if you dessicated it then mixed with the fuel (an is only ox and fuel for high order detonation, it won't burn) and dessicated again then made the fuse and dipped it into something waterproof like nail polish then it might work if its very intimately mixed.


    Reply 10 years ago on Introduction

    I am having trouble finding ANY nitrate. Help? (If you know where to get pottasium Nitrate that would be awesome!!!)


    Reply 3 years ago

    You can order potassium nitrate online from a place called the seed farm. Just bought a bag from them myself.


    Reply 10 years ago on Introduction

    cubie2, if you live in US just go to lowes and buy spectrcide stump remover it come in granules.


    Reply 9 years ago on Introduction

    to cubie 2
    actually most poeple dont live in the us
    india and china are the most populated countries in the world
    for india the population is 1,186,032,000 (2010 estimate , cencus is going on)
    for china the population is 1,338,612,968
    and for usa the population is 310,249,000
    shocking isnt it?


    Reply 5 years ago on Introduction

    Cubie2 did not say that most people live in the US. Your reply did not help


    Reply 9 years ago on Introduction

    why not try a different oxidizer like percarbonate or calcium peroxide, percarb is in oxyclean and peroxide you get from hydroponics shops. they both make great flash powders.


    Reply 10 years ago on Introduction

    get some sodium chlorate (weedkiller) make sure its above 50% that should do and if you melt it down with sugar 2:3 it makes smoke bombs :)