Homemade (Waterproof) Fuse, for Homemade Fireworks

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Introduction: 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.

L

Step 1: Materials

The essentials:

Cotton string.
Glue
Inorganic oxidising agent*

Tools:
Polyethylene (HDPE) milk bottle (or similar)
A knife or scissors
Tape
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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198 Comments

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

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?

Would powdered sugar work as an oxidizer?

No, you need something like a nitrate

L

would amonium nitrate work? the kind in instant cold packs

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

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.

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

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.