How To Make a Smoke Bomb

[caleira1616]

The smoke bomb you would purchase from a fireworks store usually is made from potassium chlorate (KClO3 - oxidizer), sugar (sucrose or dextrin - fuel), sodium bicarbonate (otherwise known as baking soda - to moderate the rate of the reaction and keep it from getting too hot), and a powdered organic dye (for colored smoke). When a commercial smoke bomb is burned, the reaction makes white smoke and the heat evaporates the organic dye. Commercial smoke bombs have small holes through which the smoke and dye are ejected, to create a jet of finely dispersed particles. Crafting this type of smoke bomb is beyond most of us, but you can make an effective smoke bomb quite easily. There are even colorants you can add if you want to make colored smoke. Let's start out with instructions for the easiest/safest type of smoke bomb you can make:
Smoke Bomb Materials


sugar (sucrose or table sugar)
potassium nitrate, KNO3, also known as saltpeter (you can find this at some garden supply stores in the fertilizer section, some pharmacies carry it too)
skillet or pan
aluminum foil






1. Pour about 3 parts potassium nitrate to 2 parts sugar into the skillet (5:3 ratio is also good). Measurements don't need to be exact, but you want more KNO3 than sugar. For example, you can use 1-1/2 cups KNO3 and 1 cup sugar. If you use equal amounts of KNO3 and sugar, your smoke bomb will be harder to light and will burn more slowly. As you approach the 5:3 KNO3:sugar ratio, you get a smoke bomb that burns more quickly.
2. Apply low heat to the pan. Stir the mixture with a spoon using long strokes. If you see the grains of sugar starting to melt along the edges where you are stirring, remove the pan from the heat and reduce the temperature before continuing.
3. Basically you are carmelizing sugar. The mixture will melt and become a caramel or chocolate color.
Continue heating/stirring until the ingredients are liquefied. Remove from heat.
4. Pour the liquid onto a piece of foil. You can pour a smaller amount onto a separate piece, to test the batch. You can pour the smoke bomb into any shape, onto an object, or into a mold. The shape and size will affect the burning pattern.
5. If you aren't going to clean your skillet immediately, pour hot water into the pan to dissolve the sugar (or else it will be harder to clean). Clean up any residue you may have spilled out of the pan, unless you want mini-smoke bombs on your stovetop.
6. Allow the smoke bomb to cool, then you can peel it off the foil.

[jackssmirkingrevenge]

Thanks for the info, but as a pyrotechnical smoke bomb such discussion falls foul of the forum Rules

[the cats in the bag]

it is pyrotechnic but its not like one of the smoke bombs that spits up 5 foot flames or any thing.

[elitesniper]

So? Its still pyrotechnic anyways.

[Jared Haehnel]

Some thing like that would be fun to shoot out of a spud gun. I've done the commercially made ones before....they leave smoke streamers in the sky its really cool to see. Especially if you've got a bunch of them in different colors...

As for the rules I think he walks a fine line....

[jackssmirkingrevenge]

The attached picture is what I would expect one of these would look like

[SpudFarm]

i made one similar a loooong time ago.. tried to shoot it with .50 tracers but no reaction i would like to try tannaritetho

this is a must try with my hybrid that is in development.

[Daegurth]

i'd strongly advise heating the sugar to temperature, taking it off the heat, then stirring in the KNO3; it's much safer. there have been several accidents where people have been heating the KNO3 with the sugar and it burning them/their house/garage/driveway.

bear in mind that anything much over 5:3, or 62.5% mix is essentially slow burning rocket fuel (which is definitely against the rules )- keep it nearer the 50:50/60:40 mark. not least because the thrust will change the direction of your projectile- potentially into a dangerous one, considering it's payload.

keep it slower burning, employ some common sense, and everything should be fine.

[pizlo]

Yeah, I thought I saw a large topic here a while ago concerning these. As far as I know they have never been successfully shot. I also want to emphasize that you may want to do this outside on a grill or fire, with protective gear, the pan has been known to spit an burn through floors, adn ruin ovens.

[fatcat]

I've seen instructions for these on instructables.com and unitednuclear.com, but have read that a different mixture is used to create colored smoke like in the picture.

[STHORNE]

heres a nice little link to a "smoke bomb-making" site.

easy to make and effective. Click Here

[SpudBlaster15]

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[STHORNE]

don't you suppose that if you left the mixture encased in the tin foil, that the concentration of the smoke would be greater (with a dime sized hole in the foil for the fuse) and you could even aim it. Also, it would project to greater lengths and last longer.

[Daegurth]

i doubt it would last longer- for low explosives, which essentially this is, confinement causes faster burning. it would be aim-able, however.

@ spudblaster: that is why you use a sugar thermometer, or other high-temperature (up to about 400C) thermometer when melting. i assumed this part was in the original post, or i'd have mentioned it before. these should be easily obtainable from the cooking department of any major department store, and probably plenty of other places too.

the ball mill method will work well, although i would press it (with a car jack or similar) into a cardboard cylinder, stoppered at one end with pressed dried clay. this would both make a projectile by itself, and help to regulate the burn time- which is why the caramelisation method exists; it regulates the rate of reaction much better than the dry powder.

but good call on the no-colour-variety and mass>volume points.

edit: i want to reiterate pizlo's point about doing it outside with protective gear, too.

[SpudBlaster15]

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