Introduction: Homemade (Waterproof) Fuse, for Homemade Fireworks

Picture of Homemade (Waterproof) Fuse, for Homemade Fireworks

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.


Step 1: Materials

Picture of 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

Picture of 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

Picture of 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

Picture of 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.


zakamooza (author)2016-04-20

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

nacreek32 (author)2016-04-11

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?

Cubie2 (author)2009-06-20

Would powdered sugar work as an oxidizer?

lemonie (author)Cubie22009-06-21

No, you need something like a nitrate


junits15 (author)lemonie2009-08-22

would amonium nitrate work? the kind in instant cold packs

lemonie (author)junits152009-08-22

I don't think so, but you could try it and see? L

junits15 (author)lemonie2009-08-22

not a bad idea

dla888 (author)junits152009-11-08

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.

nacreek32 (author)dla8882016-04-11

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

bremac (author)dla8882010-08-30

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.

Cubie2 (author)lemonie2009-07-01

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

nacreek32 (author)Cubie22016-04-11

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

voltagedude (author)Cubie22009-07-14

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

Cubie2 (author)voltagedude2009-08-14

tried couldn't find it anywhere (yes i live in the us most people do.)

akinich (author)Cubie22010-09-15

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?

TomOlsen (author)akinich2014-07-21

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

bremac (author)Cubie22010-08-30

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.

bustedit (author)Cubie22009-09-15

right, most people live in the U.S. brilliant.

mas-retals (author)Cubie22009-07-05

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 :)

BaoN (author)2014-10-29

You can get water-soluble N fertilizer which is almost entirely KNO3.

mthosar (author)2014-10-15

can I use blackpowder or some thing else ???? because in india oxidizers and nitrates are not availbale on a scale where you can buy them .

mthosar (author)2014-10-15

can I use blackpowder or some thing else ???? because in india oxidizers and nitrates are not availbale on a scale where you can buy them .

JakubM1 (author)2014-09-16

Perhaps you could use something flamable to glue the oxidiser. What about parafin or resin?

Väterchen Frost (author)2014-02-20


gabegeforce (author)2011-02-21

is the inorganic Inorganic oxidising agent the sodium-cholrate? the weed killer which can be bought in farming stores where they sell potassium nitrate?

comsa42 (author)gabegeforce2013-05-19

A good way to make sodium chlorate for mass production is to use electrolysis.
Check out this guide:

lemonie (author)gabegeforce2011-02-22


gabegeforce (author)lemonie2011-02-22

thank you!! I guess I have to do this now, I'm excited, I'm making my smoke bomb, I wanted to make a pull ring action using matches but I wanna try it with a firework fuse first. this is great!! by the way, I can't find a organic dye to color my smoke bomb, do you have any idea what will work to put color in my smoke bomb?

cbaik (author)2013-05-13

Was that soundtrack from dwarf fortress?

smiley G.I JOE (author)2012-11-01

is there a substitute for inorganic oxidising agent

lemonie (author)smiley G.I JOE2012-11-02

An organic one I suppose, like nitrocellulose or glyceryltrinitrate.


RocketPenguin (author)2012-06-20

will this burn into holes (i.e. a rocket engine) or will it die when it hits the clay nozzle?

copper tube (author)2011-06-25

please answer soon! did you can only put epoxy on the rope and tada its a fuse

lemonie (author)copper tube2011-06-25

No, glue alone doesn't burn like that.


Raydoom (author)2010-12-03

instead of epoxy could you use dextrin? ,its like pyro glue wen mixed with water

lemonie (author)Raydoom2010-12-03

Yea, but it'd not be water-resistant.


oldmanbeefjerky (author)2010-11-22

also i want to ask, would this work if i replaced the epoxy with bike tire rubber solution, and if anyone else has tried with it

lemonie (author)oldmanbeefjerky2010-11-23

You could try it?
(I don't know)


oldmanbeefjerky (author)lemonie2010-11-23

i will, i have already orderd some of the stuff from ebay, i just wanted to be sure is i swear ive heard it soem where else that you can use liquid rubber.
anyway ill ask you this, what consitancy was the oxidizer used, was it like flower? or larger thasn that?

lemonie (author)oldmanbeefjerky2010-11-24

Like flour. (or icing-sugar)


oldmanbeefjerky (author)lemonie2010-11-24

exellent, thats how fine i managed to make it, i also just found some epoxy, so ill have to try it right away

oldmanbeefjerky (author)2010-11-21

you know, ive come to notice that you havent mentioned exactly what oxidizer you used, you said what one you can use, but not the one you did use, also, epoxy glue comes in two parts, and you didnt say anything about using the other part of epoxy. are we supposed to only use the epoxy, and not the hardener?

nextly what i also need to know is, you have to dip the cotton in water at the end of the instructable?, you said if it doesnt burn, dip in water and try again........ how does tht work?

lemonie (author)oldmanbeefjerky2010-11-22

For 2-part epoxy you use both parts.
I don't recommend messing with sodium chlorate.
You don't have to dip it in water, that just demonstrates that it does still burn.


oldmanbeefjerky (author)lemonie2010-11-22

ok, but what oxidizer did you use, potassium nitrate?
you said inorganic axidizing agent, that means it could be pool chlorine, or sodium peroxide!

please be more specific!

bremac (author)2010-08-26

prior to commenting it would nice and more respectful to the author if you were to actually read the thread his topic supports rather than just blurting stuff out like a two year old. HOw many times will someone say "isn't KNo3 saltpeter"? Oxidizers (useful in this type of chemistry): potassium nitrate, sodium nitrate, ammonium nitrate, cupric nitrate, ferric nitrate potassium, sodium, ammonium chlorate and perchlorate potassium permanganate, calcium peroxide, dichromate, potassium persulfate, sodium percarbonate, triazone, potassium and sodium bromate or iodate or perborate the identity of oxidizers is no government secret and every last one of those I mentioned are available in stores around you if you know how to find them (i don't want a million emails about where to find them, do your due dilligence before asking please) the overly reactive and somewhat dangerous would be permanganates, chlorates and bromates. although I appreciate the scientific effort that went into the research of this instructable (after all that is how science is discovered) however it is over kill and results in a product that is not reliable. Making a fuse is as simple as taking a nitrate salt that is very water soluble and making a hot saturated solution of it, then take some cotton butcher twine and unwind it to loosen it, dip it in the saturated solution of nitrate and let it dry, it will burn like a firecracker fuse. It will not burn underwater as it does not burn hot enough to overcome the cooling effect of the water. You need black powder to burn underwater, try filling maybe some shrink tube with it and heat shrink it for a nice tight tube of bp, that will burn underwater. never use metal powder in a fuse, it could burn so fast you won't know what hit you. In your instructble the epoxy is neither a fuel or an oxidizer I'm afraid, unless I am mistaken you are using cotton string, that is essentially cellulose and becomes the preferred fuel for your chlorate salt. WATERPROOFING can be done by taking pingpong balls which are pure nitrocellulose and dissolving them in acetone, then coat your fuses with this solution and let dry, it will aid the burning as well, it is nitrocellulose lacquer. Come on people ask this gentleman some intelligent questions, he went to the effort to produce this instructable, the least you can do is put in the same effort by reading the conversation before saying something stupid just becuase you like typing. And the insults? well that just shows your intellect level, very typical of those who say but don't do, always the first to pee their pants and run home to hide under the bed when someone fingers them. Anyway bro, try what i've suggested and let me know what you think, try filter paper rolled up too, thats the most reliable, and get it really dry before lighting.

lemonie (author)bremac2010-08-26

I don't fully understand your comment, but to split into paragraphs:
it's a water-resistant fuse, and the epoxy-glue is burned.


bremac (author)lemonie2010-08-30

perhaps i rambled a bit, was addressing a few comments i read throughout the thread from people who have no business playing with this stuff if what they display is an accurate depiction of their knowledge behind pyro. there was much talk about oxidizers and where to find them. the oxidizers to use are no big secret and highly available, you just know where to look as i am sure you do. anyway, to address what you are saying regarding the glue. I am not just making claims i have heard in pyromaniac folklore, I am a Msc in organic chemistry. the reason the glue in your case in burning is because it is binding up the oxidzer, what i suggest is to soak the oxidizer into the cellulose cotton material and dry it. that way you have much more intimate contact between ox and fuel for a consistant burn rate throughout. If you try to glue bp onto string you'll get inconsistant burn rate and in my opinion (correct me if i am wrong) you get hot spots on this type of fuse since its impossible to ensure even distribution. since it is inline with this thread i wanted to ask you what your experience may be with fuses made of extruded or rolled rocket candy with a bit of corn syrup to reduce brittleness. And what your opinion on the use of golden powder as a replacement for black powder. I swear by golden powder if its cooked for flash and report but i'm curious if anyone has used it for rocket engines. I've head yellow powder is a great substitute as well but i've not made it.

lemonie (author)bremac2010-08-31

(I might sniff at the MSc as I have a doctorate, but I liked the comment)
The reasoning behind this was - stable moisture-resistant rocket-propellant, so this essentially a spin-off from my space-project.


bremac (author)lemonie2010-09-03

so are you saying you have attempted a rocket fuel made from glue and oxidizer?

About This Instructable




Bio: 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 ... More »
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