by Whatsblem the Pro

While it’s an amazingly bad idea to fool around with making your own fireworks in general if you don’t happen to have a knowledgeable qualified pyrotechnician on hand, there are some fireworks you can easily make yourself, safely and cheaply and without the risk of losing any extremities.

Smoke bombs top the safe ‘n’ sane list, and in their own way they can be just as fun and useful as even the more extreme blowy-uppy and melty-throughy varieties of recreational DIY combustibles, like tannerite and thermite.

Don’t try this at home. Or anywhere else.

Like thermite, smoke bombs are very easy and cheap to make quickly at home, and almost as safe to manufacture, store, and transport. . . but unlike thermite, which is horrifically dangerous once ignited, and shouldn’t be meddled with even in small quantities unless you know exactly what you’re doing, smoke bombs are safe enough that ordinary common sense will prevent you from suffering any serious consequences. Please note that while tannerite is only a little bit tougher to make at home than smoke bombs or thermite, tannerite absorbs water from the air over time and, in the process, can become unstable enough to self-ignite. In other words, if you don’t have someone qualified around, you might want to limit your pyro DIY to smoke bombs.

I’m going to divide the making of smoke bombs into three categories: Basic, Advanced, and Kit. Basic smoke bombs are minimalist things; the Advanced instructions will take the Basic smoke bomb and add various fancy-lad options; Kit smoke bombs provide the best of both, offering ease of manufacture with tons of options (especially for colors).

BASIC

The most basic smoke bomb of the variety we’re going to discuss requires only two components: ordinary refined white table sugar, and potassium nitrate, aka ‘saltpetre.’ You’ll also need a skillet or frying pan, and some aluminum foil.

Check the label; use 100% potassium nitrate

You can buy the sugar at any grocery story, obviously, but where do you get saltpetre?
At the store, of course! Maybe not the supermarket, but Lowe’s or Home Depot or the gardening center at any number of big box stores will usually have it, as will some feed stores and farm supply outlets (potassium nitrate is a fertilizer). Ask for saltpetre or potassium nitrate by name, or look for Spectracide brand Stump Remover or similar products. . . but check the ingredients list on the label, and make sure it says “potassium nitrate,” “saltpetre,” or “KNO3.” Spectracide’s product is 100% potassium nitrate; don’t settle for anything less!

You can also buy online, at any number of places. Check Amazon, or try a chemical supply house. Skylighter.com is a pretty comprehensively-stocked distributor of pyro supplies, and can furnish you with everything you’ll need, including saltpetre.

You can also just make your own, if you really want to go to all the trouble, by reacting ammonium nitrate with potassium chloride. . . but we’ll leave those instructions for another time.

So, you’ve got your sugar, and you’ve got your potassium nitrate. You’ll also need a nice big skillet (teflon-coated or other nonstick, if possible), and a range to cook on.

Break up any clumps in the potassium nitrate and the sugar; you want them to be free-flowing, finely-divided powders. THIS IS CRITICAL, as even a small amount of clumping will cause your smoke bombs to be hard to light and prone to going out. Run your ingredients through a sifter if necessary. Once you’ve got them both finely divided, mix them together in a 3:2 ratio. It’s not a critical ratio, so you don’t need to weigh them out; just measure by using a spoon or a scoop of some kind; three scoops of potassium nitrate to every two scoops of sugar.

Warm the skillet over low to medium heat, and put the sugar-saltpetre mixture in it. Stir continuously with a wooden spoon (so you don’t scratch the pan’s nonstick coating) until the mixture melts together and the sugar begins to caramelize; it will resemble smooth, light-colored peanut butter when it’s ready.

I repeat: STIR CONTINUOUSLY, AND DO NOT leave the pan unattended on the stove; this isn’t a terribly dangerous procedure, but if it does catch fire you may not be able to find it to put it out before it fills your entire house with smoke and burns the place to the ground. Even if all you do is smoke up your kitchen, it’s going to attract hordes of flies the next day, so keep stirring and don’t let it catch fire!

Don’t worry about contaminating your skillet; clean-up can be accomplished with nothing but water. Also, potassium nitrate is often used as a food preservative, and this mixture you’ll be working with is entirely non-toxic (but avoid breathing the smoke when you set it off). Eating it isn’t recommended, but it won’t hurt you a bit, and any residue left in the pan after washing is ignorable.

Once you’ve got a nice smooth brown mixture in your pan, treat it like cookie dough (but don’t bake it). Spoon rough spheres of the hot mixture onto a sheet of aluminum foil, and let them cool and harden. Done! Peel them off the foil, take them outside to an appropriate spot, and hold a lit match to one until it catches. Smoke bomb!

ADVANCED

Perhaps the most obvious option would be to add a fuse. I won’t go into the intricacies of rolling your own fireworks fuse in this article (maybe another time), but it is doable if you don’t want to simply buy it online. Again, try Amazon, or Skylighter.com. The type of fuse known as ‘Visco’ and sometimes referred to as “cannon fuse,” “fireworks fuse,” “safety fuse,” or “wick” is ideal, but it’s not critical, as a smoke bomb isn’t going to blow your hand off no matter how iffy the fuse might be.

Adding a fuse can be as simple as shoving a length of your preferred fuse into the smoke bomb right after it leaves the pan, while it’s warm and soft. For best results, poke a hole in the cooling mixture with something rigid that is bigger but not too much bigger than the diameter of your fuse (an ordinary pen works well). Wait an hour, drop the fuse into the hole, then push a small amount of cotton wadding (tear apart a cotton ball) down into the hole alongside the fuse to secure it.

If you want to do the job extra neatly and also make your smoke bomb last longer and give off smoke a little more effectively, add some containment. This can be as easy as filling a section of cardboard tube from a toilet paper roll, paper towel roll, or frozen “push-up” confection with the warm mixture of saltpetre and sugar you’ve prepared, inserting the fuse, and wrapping the whole thing tightly in duct tape with the fuse sticking out, leaving a small open space around the fuse to vent the smoke. Packaging your handiwork this way is also helpful if you intend to store or transport smoke bombs, and don’t want your storage area littered with detritus. Instead of using a cardboard tube and duct tape, you can just wrap your bombs in aluminum foil; this will, however, leave more mess to clean up after the smokeration is over.

If you want to get really super-fancy about it, you can press the hot mixture of sugar and saltpetre into a mold, for a decorative look that says “I buy all my fireworks from Tiffany’s, peasants,” or perhaps a nice hand grenade motif.

Another option: Right after removing your skillet full of fun from the heat, add baking soda to make your smoke bomb burn more slowly and evenly. The proper ratio of saltpetre to sugar and baking soda is 9:6:1; nine parts saltpetre, six parts sugar, and one part baking soda. Mix the baking soda in quickly but thoroughly just before removing the mixture from the pan.

Aniline-based dyes for the win

What’s more awesome than a homemade smoke bomb? A COLORED homemade smoke bomb! There’s a whole range of colors you can add to these little gems, but you’ll want to be picky about the dye you use. Don’t use water-soluble dyes, like food coloring. These may (or may not) change the color of the flame, but they won’t give you the bright-hued smoke you’re looking for. Aniline dyes, sometimes sold at art supply/craft/hobby stores as “powdered organic” dyes, work well, and you may even be able to find them in the laundry section of your local supermarket. Check the ingredients list on the label carefully to make sure you’re buying an aniline-based dye!

Just after removing the pan full of sugar-saltpetre mixture from the heat, and after mixing in the optional baking soda if you choose to use it, it’s time add the dye. The optimum ratio of saltpetre to sugar to baking soda to dye is 9:6:1:9, so the amount of dye you add should be equal to the amount of saltpetre you used. Again, make sure the dye is finely-divided and free-flowing before you mix it in, and not a mass of lumpy, clumpy, chunks. You should be able to manufacture a huge variety of colored smoke bombs this way, although blue and orange work best with this type of smoke bomb.

KIT

Sure, take the easy way out. . . and why not? You can still say you made your smoke bombs at home, and you’ll avoid having to make multiple trips to different types of store to obtain your materials. Smoke bomb kits are an ideal combination of convenience and DIYitude.

Skylighter sells a reasonably stunning array of smoke bomb kits in a whole rainbow of colors (even pink!) that you can put together at home, but they are often out of stock, so you might have to sit on your hands a while before you can get started. Take note: these kits use a different mix of chemicals than our sugar-and-saltpetre concoction, so you’ll want to set this article aside and follow the instructions that come with the kit instead. On the plus side, this different type of smoke bomb offers more vibrant colors than the saltpetre-and-sugar variety.

I shouldn’t have to say this, but I will: BE CAREFUL. Smoke bombs are relatively harmless little beasts, but anything that is on fire poses a hazard, and you do want to avoid inhaling the smoke, although a little won’t hurt you. You can also create quite a hazard by setting these things off in the wrong place; the middle of the freeway is a poor choice of locales for creating a giant opaque wall of colored smoke. Use common sense; it’s nice to stay alive and enjoy your shenanigans without falling into the rookers of the millicents for it.

Burn on!