Like it was said before, always mix it wet! Static electricity is what set off the DuPont's explosions . At least that is what they have attributed them to. Could have been any number of causes, but that is definitely the number one on the lists. Especially on a cold morning. I think they worked bare foot, in the buildings. As for mixtures,or formulas, the Fox Fire series of books has a recipe for black powder. On an outdoor special one time a long time ago, about the early to mid seventies, there was a story about and old guy in California, who was living in the California mountains, and it showed the home he built in the side of a mountain, among the rocks, and how, made a rock gate, with home forged hinges, and marbles for bearings, and bear grease, which he got from bears he had killed with his home made muzzle loaders, and using his own home made black powder. He told the mixture he used, and when he mixed it, instead of using water, he used urine, and he got the best results from using alder charcoal. He had experimented with various types of willow, and other wood, but he said the Alder gave him the best results. There used to be people whose job it was, to go around at night, and collect the trays put in out houses, to collect the poop and such, (night soil) and dump it in a wagon, and take it back to the place where it would be processed to leach the potassium nitrate out of it. They would make a more or less hay manger, supported by upright poles, and filled with hay or straw, and underneath this would be a trough to catch the drippings. They would dump the night soil on top of the straw, and then pour water over it. The potassium nitrate would leach out and collect on the straw, and in the trough beneath, When dry the little crystals of potassium nitrate would be gathered and then crushed, and then mixed with the charcoal and sulfur. I remember reading in an OLD book that was about hunting, woods lore, and such, and it had a big caution about shaking a can of powder to see how much was in it. It warned about static electricity setting the powder off! That is why commercial powder now uses a coating of graphite, to prevent that. I was never successful in the rocket projects I tried. They either blew up, which was just as satisfying, or just fell over, and fizzled, and burned up. Then I got idea to just use a Co2 cartridge instead of powder. There were lots of possibilities for that, that I won't go into here. NSA and all, you know......
8)We're being watched
In the Army I was a Cryptographic clerk, and we were always told to be careful what we said to others at the end of our transmissions. As the NSA was peeking. Their shoulder patch was a lightening bolt grasped by a golden claw, and black feathered leg. We used to call them the "Lightening fast Chicken @#%$#%s." ! Has to do with sex And all that sort of nasty stuff soldiers hear now and then......
Any who, do be careful, with experimenting, if you do make some, make small batches, and keep each separate, in non plastic or metal containers, that would conduct static electricity, and then after you have the amount you need, combine it. Potassium Nitrate is very hydrating, as it will draw moisture from the air. But a humid atmosphere keeps static electricity down.
Just be careful I once showed a Friend of mine how to make Co2 cartridge ...... uh entertainment, items, like depth charges we used to make with the old and better M80's, and he was with some Friends, and they were lighting them, and I had told him absolutely no fuse shorter than 6 inches, and as soon as it is lit throw it as far as you can! Well they said all was going well till he lit one, and just stared at it. He says even to this day, he doesn't know why he didn't throw it, even when his Friends were yelling at him to throw it. Well he has part of a thumb, and various lengths of other fingers, and a piece of the metal cartridge lodged near his heart! Black Powder is an explosive! Be it a poor one, nonetheless it has the potential to be deadly, as you have read previously here on this blog. I say again, please be careful, small batches and wet, and remember, it is not coated with graphite, so it is sensitive! How would you coat it with graphite, well, I believe the mixture is granulated to size, and the dampened, and lightly tumbled in graphite. Not sure of the commercial process. At one time, you could order a fifty pound brass container of pea sized black powder, that was once used in torpedoes, from Dixie Gun Works.
Wish I would have ordered one or more of those when they were available. But money was a bit tight then, and has not changed a whole lot since.
Be careful, I kinda like reading all the posts on here, and would like it to continue.
Wayne