Sciencemadness Discussion Board

short question about colored smoke bombs

sarinox - 3-8-2024 at 02:04

Hello all,

As u can see in the below link a person shows a method of making colored smoke bombs using oil pastel! I know for sure this is a hoax! but I wonder does any of you know what actually works? Could any of you point me in the true direction of making colored smoke bombs? the reason I am asking you instead of watching another YouTube video is I don't want to fall into another possible trap or dangerous process!

https://www.youtube.com/watch?v=_9Tkq3K1q_c&t=103s

-Sarinox

Fery - 3-8-2024 at 02:47

You need thermostable organic dyes which sublime without decomposition. The base pyro compound (white) should burn at quite low temperature. KClO3 + S + NH4Cl (IIRC 30 g : 20 g : 50 g) or maybe KNO3 + powdered sugar 50:50 grams (but I suggest the first one). You add there the coloring organic substance. I've bought red, blue, green, yellow colors some time ago but I do not know their formulas. I was able to find the invoice and they were quite cheap only 2 EUR per 100 grams of each of the 4 dyes. The label on package just stated red/blue/green/yellow smoke color without mentioning exact chemical formula. It is cheaper to buy ready smoking compounds (airsoft shops) than mixing them at home from all the necessary components. But preparing at home is more fun!

edit: I found some info here:
https://uranit.cz/view.php?page=dymovniceb
they claim Sudan-I for red, indigo for blue, alizarin-S + indigo for green, alizarin-S for yellow

also this video is amazing and they share the composition:
https://www.youtube.com/watch?v=EWaEhLhgeso

[Edited on 3-8-2024 by Fery]

sarinox - 3-8-2024 at 04:19

Thanks Fery :-)

greenlight - 3-8-2024 at 09:57

Fery is correct, you need a organic dye ( many are available on ebay if you search smoke dye like solvent green solvent yellow, etc.) Rhodamine B, while getting on to every surface and turning it right purple, makes a beautiful pink/light purple colour.

The pyrotechnic composition you use must produce enough heat to vaporise the dye without burning and decomposing it as well as sufficient gas to disperse it.

The low reaction temperature required narrows it down to one oxidiser, potassium chlorate. A usual fuel is lactose which is cheap and readily available. The reaction equation is as follows:

8 KClO3 + C12H22O11•H2O 》》》》8KCl + 12 CO2 + 12 H20

Magnesium carbonate or sodium bicarbonate is also sometimes added as an acid neutraliser and coolant.

The dyes are strong absorbers of light. This light is reflected off the sublimed dye when it condenses in the air which is why the resulting smoke is so vivid and bright in colour.

You can also mix different dyes in a way similar to mixing paints to achieve different shades of the same colour. For example, blue and yellow dyes can be mixed in various proportions to result in different shades of green



sarinox - 3-8-2024 at 12:33

Tanx Greenlight :-)

sarinox - 3-8-2024 at 12:36

By the way is any of these substances (such as Rhodamine B) prone to release toxic byproducts when heated? or their vapors are they going to be toxic?

greenlight - 3-8-2024 at 19:13

The solvent dyes are the same ones used by the military and are pretty safe. I think the rhodamine b is a suspected carcinogen.

The safety is the same as when the dyes are in their original powdered form as you are not burning them to release by-products.
You are simply sublimating them with heat and then they are recondensing into solid dye particles in the air again.

Just don't go purposely inhaling them which you can't as the "smoke" is quite overwhelming if u breathe some in.