How to Start Fire With Water!




About: I'm Nicolaj, a Danish chemistry student interested in DIY and projects involving fabrication.
You probably already know a few ways to do this, but none that beats this method! It will not only make you be able to start a combustion with a drop of water, but it will be the coolest GREEN flame!

For a brief description please watch this video:

Note: Alot of people have mistakenly claimed that I have stolen video and pictures for this Instructable. To clear everything up, I didn't steal anything, I simply posted elsewhere long time ago, and eventually it became popular on the internet. Look in the beginning of the video for the signature.

Step 1: Materials

Before we start, I must warn you. This is obiously NOT a safe experiment you should allow small kids to make, as this will combust with an explosive-like effect with a drop of water, and might not always go off the way you want it to. This mixture is hygroscopic (will soak moisture from air) because off the ammonium nitrate included. So if it is very humid or raining, making this is not a good idea.

Okay, so let's get started!
For this project we will need following items:

- An "Instant cold pack"
- Table salt
- Zinc powder (grey metal powder, can be bought from or

Further you'll need

- A scale, preferably precise to 0.1g
- A mortar and pestle to grind the mixture

Step 2: Ammonium Nitrate

Start by cutting open the Instant cold pack. You'll notice there are two things inside:

- A bag of water, that you can throw away.
- White granules, consisting of ammonium nitrate.

We want the ammonium nitrate for this project, as it will act as oxidizer.

Step 3: Grinding

Now we will need to weigh out the following:

- 3g Ammonium nitrate
- 0.5g Table salt

Transfer it into the mortar and pestle and grind, untill it's well mixed.
Now comes the part were you need to take precaution, weigh out:

- 7g Zinc powder

Put it in the mortar and pestle and grind it together with the other ingredients.
Care must be taken at this point, not to let any water near this stage, since the powder is now finished and ready to use. Use it instantly, as storing the mixture will guarantee problems.

Step 4: Igniting

The only thing left to do is to ignite it.
To do so, add a few drops of water with a syringe or pipette (or stand well back and see if you can hit it with spit!)
The important thing is to wear safety gear, such as goggles or gloves.

A few seconds after the water is added, smoke will appear, and then a combustion will occur with a bright, green flame.

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    240 Discussions


    2 years ago



    3 years ago

    There is a misconception that seems pervasive throughout the comments and that is that the flammability of any of the compounds is any sort of factor in this reaction. The issue is how many carbons can be oxidized from their present state to a more oxidized state and how many further oxidations of the same carbon can occur. Further, Ethylene Glycols are hygroscopic and the smaller the molecular mass the more that is the case, although, at the other extreme, the solid -highest mass- ethylene glycols are not hygroscopic at all. So what does that mean? It means that undiluted Polyethylene glycol will work and that diluted will not. Huh? Yes, some water is needed normally to start the oxidations with the oxygen provided by the permanganate; however, in excess, the water stops -as it does many other, ask Wallace Carothers- the oxidation reaction. When treated with acid and in the presence of potassium permanganate, the carbons in question will fully oxidize; that is to say that primary, secondary, and unsaturated carbons will have electrons added to them from the permanganate. PubChem specifically states that a mixture of Polyethylene Glycol and Potassium Permanganate is, all by itself, spontaneously flammable; therefore, negating the need for ammonium nitrate unless....

    The formation of Ammonium Permanganate when a mixture of as low as 0.5% Potassium Permanganate and Ammonium Nitrate results in an explosion when a threshold quantity of Ammonium Permanganate has been reached. The reader is cautioned concerning reliance on estimates of seven hours as temperature and pressure play a significant role and a role that, for those incidents, remains unknown. Moreover, the relationship is non linear and therefore any attempt to predict the rate of formation of Ammonium Permanganate under any conditions is fraught with perils. Temperature is certainly going to accelerate the process so that if used to light a campfire, said campfire might suddenly and without sputtering or sparking any more than would normally be the case, explode.

    It is posible to use a small piece of bicycle inner tube, when sealed with wax at one end and packed with dryer lint, a fair quantity of permanganate or perchlorate such that when surrounded by further dryer lint and wax, a shelf stable product may be made. Then, when desired, a small amount of some material with the aforementioned oxidizable carbons may be added by poking a hole in the wax and adding the material directly into the permanganate saturated dryer lint that is surrounded by rubber; the resulting fire will burn enough to dry wet wood! It is also possible to create stages such that once a fire is started, the permanganate consumed, the melting of a sufficiently thick wax plug or a gelatin capsule would liberate an amount of magnesium oxide (alternatively, one may use strips of magnesium oxide on the inside of the second piece of rubber so as to both ignite the rubber and increase the temperature of the fire. Undoubtedly, magnesium oxide powder could also be blended into a wax plug and these might be carried as a source of preprepared fire starting material by encasing the magnesium oxide in the wax with dryer lint and surrounding this with a piece of inner tube. Why go through the trouble? The inner tube's border can serve to contain an amount of powdered sugar. This sugar, while totally unreactive with the magnesium oxide, would react violently with potassium permanganate when a small amount of water is added. Dissolved in Polyethylene glycol, the reaction with the permanganate would be something to see indeed given the added carbons available for oxidation.

    Having saved the best for last, her it is: permanganates ignite in contact with polypropylene. While it may take more of either, it presents a safe manner in which to carry the permanganate in as much as one can keep it in its original polyethylene container and merely carry or wear the polypro until needed. One major disadvantage is that the reaction will not be as spontaneous as that which would occur with glycerol or glucose paste.

    Similarly, one can combine antimony with potassium permanganate and when ground together, a moderate rate of oxidation will occur. That is, a fire, though the reader is cautioned that what a small amount makes into fire, a large amount makes into an explosion.

    Personally, I would avoid the usage of ammonium nitrate if at all possible. However, given how its presence alters the reaction kinetics, it might be desirable to use a small amount if one has lots of ammonium nitrate but only a small amount of potassium permanganate.

    The experiment described in the article to which this response is attached is fine when sufficient precision is available and used. Nevertheless, if one finds oneself in such a situation as the man in Jack London's tale "To Start a Fire", I imagine that a more some of this and some of that approach might be better suited.


    4 years ago on Step 3

    Everyone is saying don't store the mixture. They're half right. Just store it in two bags - the fuel and the oxidizer in separate bags - and mix when needed.


    4 years ago

    two years ago i did this experiment for my classmates to get them excited about chemistry. i have found the more reactive the metal in the salt is the better. potassium is 3 to 4 times more powerful that sodium . i haven't got to treat lithium chloride it should be the most reactive.


    4 years ago on Introduction

    be careful when making this, as it may be illegal to intentionally create an explosion in some states. Massachusetts is one of them. The fine's anywhere from $10- $100, but it's unlikely you'll be caught.


    Reply 10 years ago on Step 4

    cold pack- sold at drugstores, used for injuries. you squeeze the pack of water inside and burst it, and the resulting reaction takes more energy than it creates, therefore making it cold. it's useful for sports, where there's no freezer around.


    Reply 10 years ago on Introduction

    Once you light a mixture that has the oxidiser in it the only way to put it out is to remove the fuel source. So unless you want to poke a stick in it and try to scrape out the un-burnt part of the mixture while it's going you basicaly can't put it out.


    Reply 10 years ago on Introduction

    You could put a bucket over it, getting rid of the oxygen. You have to eliminate one part of the fire triangle, source, heat, and oxygen


    Reply 10 years ago on Introduction

    The amonium nitrate serves as an oxidizer, it doesn't need oxygen from the air.


    Reply 9 years ago on Step 4

    If you have no idea what a cold pack shouldnt be trying this experiment!!!


    5 years ago

    A lithium strip from a disposable battery and a cup of water work just as good.


    5 years ago on Introduction

    COOOOOL!anybody with a few braincell,s can do this and its FREAKIN AWESOME .
    Can we increase the explosion by increasing the components like everythingx2


    6 years ago on Introduction

    Would pottasium clorate replace ammonium nitrate
    then could i use pottasium cloride as the salt