Ok, I know, I know, basic stuff, but I am perplexed...
I looked up the formula, just out of interest, for the decomposition of BP and I found this : 10KNO3+3S+8C---->>2K2CO3+...Products.
I don't really care about the products so I won't mention, but the equation made sense.
However, according to this formula, by mass, BP is 84.01%KNO3, 7.995%S and 7.986%C. This significantly differs from the generic formulas out there. Why?
P.S I got the equation partially from my head, partially from Wiki.

where did you get that formula?

alot of the different formulas you fond for BP differ because the effect differs with different ratios of fuel:oxidiser

take foe instance Tiger tails... LOTS of carbon.

why? because you want the "senko hanabi" effect of branching sparks.

KOH ans S offer the same effect if processed correctly...wait a while till you work with that though please.

there is WAY to much oxygen in that formula. did it say the source of the powder? how it was calculated? might need to edit that wiki article...

It doesn't account for atmospheric oxygen among other things like the purity of the potassium nitrate and sulfur... and the type of charcoal... Charcoal being probably the most important variable aside from the level of integration. Charcoal isn't 100% carbon either, it generally has other stuff in it, sometimes left over volatile oils, sometimes carbonates, etc.

Pyrotechnics isn't an exact science.

The composition of BP early on... many many many years ago... varied slightly... This being because one composition worked slightly better than others for whatever main use they used it for based on their raw materials, like source of charcoal and what kind of equipment they had available to grind the powder... SO... It varied by geographical area.

BP is a huge subject that has filled several books up.

Edit: TT has alot of carbon because your wanting a thick tail, the star smoldering more than burns and a good portion of the oxygen comes from the air as the star is in flight... The air also blows off the smoldering charcoal. Senko Hanabi and glitters are a completely different, VERY complex chemistry. Theres a book or two specifically about glitters.

A chemist with probably very little real knowledge of pyrotechnics probably calculated that formula out. That doesn't mean he is a bad chemist, he just didn't really research it... Hmm... on second thought he is a bad chemist for not researching it.

touche...got the titles of said literature?

The Pyrotechnic Phenomenon of Glitter by Robert M. Winokur

Glitter the Chemistry and Techniques by Lloyd Scott Oglesby


I havn't read the first. I have read quite a bit of the 2nd though... maybe a year ago.

Both are likely available at the big amateur pyro suppliers. IIRC Winokur's work is only available through a newletter or something where he allowed it to be fully re-published. So in other words that one would come with info on other projects and likely be a great deal shorter than Oglesby's full blown book.

something i find odd about my tigertails is that thay crackle and the sparks explode like a hanabi i made before

I guess Its the process I use and the charcoal

thank you for the titles

Ok folks, thank you very much for tyhe info, now I'm slightly smarter... Still a dumbass to some extent tho. Thankis for the literature too, I'll be sure to have a read. Now off to wrtie my chemistry exam.

As a general rule: don't bother too much with stoichiometry when it comes to the low end of low explosives.

Reactions vary strongly, chemicals decompose, stuff gets blown out of the mix ...
Ideal compositions get determined experimentally.

like the best ratio of oxidizer to sulfur for the best... well... lol my lungs hurt :p