So recently i have been diving into the realm of Pyrotechnic devices for the purpose of using them in airsoft. This led to the idea of making smoke grenades for my friends and i to use while we play our games.

So down the rabbit hole i delved.... and this is my progress so far

Starting off, i purchased a 5 ibs bag of Potassium Nitrate, 10ft of fuse, 2 pound bag of pure parafin wax, and pure granulated sugar. I decided to use wax as a binder for the dry ingredients instead of cooking the dry ingredients together into a paste, simply because i heard it can produce better results and burn slower, allowing a steadier stream of smoke.
At this point i realized i have not considered the container i want or need to use for these smoke grenades, but i figure i could use reinforced TP tubes, and soda cans. (these would not work for me in the end)

To test my mix's, i used these little 4oz paper cups to pack my mixtures in, lit the edge of the cup, and then put a small clay planting pot over them (the small diameter of the hole in the bottom of the pot let the smoke escape and prevented flames from popping up, as well as keeping a decent pressure to make the smoke flow densely for these small control tests.) These tests were done prior to packing any canister and testing the full sized variants.

My first batch of mixtures was a 2/3 Sugar/Nitrate mix. The recommended mix from everything i have found.
The results were great, ignited extremely easily, but it burned hot and melted the soda can, and TP rolls went to ash.
Due to this, fire would start burning and stop the smoke. (the soda can lasted for a good amount of time, but after the can melted and the flames started, the last 3 minuets of burn was wasted on smoke.

To solve my containment issues for my full sized tests, i purchased a 1-1/2"x6" metal tube, a cap to go with it, and a 1-1/2" to 1" metal fitting for the other end.
This is a solid little canister does well for "full sized" tests. However it is Metal, so you will need to wrap the cap and middle of the tube with heat resistant covering to avoid being burned. Dont wrap the other fitting so you can remove it to clean the canister and pack it. Really handy reusable design.

My second batch consisted of 0.7/1.4 Sugar/Nitrate (Roughly measured)
This mix produced really good smoke, however due to user error, i used WAY to much wax, creating a wetter mix that did not ignite as easily. When ignited however, the smoke was great. I will test this further with reduced wax content to see if i can get the perfect smoke grenade made for my uses.

Danger Alerts: I know most recipes call for cooking your blend of Nitrate and Sugar. I chose not to do this. But due to over use of wax in my last batch of tests, i decided to give this a try.
This ended up.. not as planned.
The Result: The mixture ignited immediately and burned with seconds on the test cake i had in the paper cup. i could not even get the clay pot over it. Thinking it was a pressure issue, i cooked up another batch and packed it into my metal canister. As soon as the fuse burned down, the mix ignited. The ignition of the mix was.... Jet-engine like. a solid pillar of fast spitting flame jetted out of the canister. A second later the flames disappeared and an explosive boom shook out, followed by a cloud of smoke (though there was a LOT of smoke before the boom also). My details are iffy, but i do have a video that shows exactly what happened. The boom was so loud that if killed the audio on the recording when it happens. Ill post and link in a comment

So all in all, be extremely careful in making your own DIY smoke grenades. Most people (like me) who know nothing about chemistry and chemical reactions, and the such, underestimate the dangers of what changing a simple step, or missing a step, or not doing a step properly, can have.

I am open to advice if anyone has any, as for all my success in good mixtures, i can always stand to learn some more from people who probably know a ton more than i on these things.
What i would love to learn, is what can i do to make the mixtures not burn as hot as they have been, As well as creating the containment device for the mixture itself. I heard soup cans can do extremely well, but they heat up like crazy so you cant hold them.
I guess what i need to learn specifically, is what i need to do to make the mix burn slower and cooler.

(side note, i may explore the explosive route again for BB grenades or Flash Bangs if i can learn more about it)

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Anyways, hope yall enjoyed the read, and found it interesting!
i can post results and vids/clips in other posts if yall would like!