Sciencemadness Discussion Board

A tip to those making Mg/KNO3 powder

minstarmin - 12-6-2016 at 16:58

Hello ScienceMadness,
This is my first real post here, so I hope I'm putting this in the right section. Anyways, a week or so ago, I ordered up some Mg atomized powder from pyrochemsource. Mixing it in a 5g:5g ratio, I put a bit in a pile with the fuse sticking out the side (fuse straight out the top of a pile of ANY explosive can cause premature detonation) and when it burned down, all I saw was a flash with some sparks. I kept trying this, in different ratios, all with very similar results and no real explosion. However, while trying to develop a good way to float the powder on my pool (don't ask why) I discovered that putting it in a bottle would cause it to explode. This worked for all the ratios I had tried before that had failed to properly explode on their own. I suppose the pressure inside the bottle makes it explode? By the way, I ran a thin fuse through the cap of the bottle with a hole drilled so the fuse would fit tightly. Maybe if you just run the fuse through the open mouth of the bottle, it would create more of a rocket effect? Sorry for the long post, just wanted to leave a few tips for those wanting to create different effects with this mixture. Have fun and be careful.
Aden

violet sin - 12-6-2016 at 17:18

With a little bit of confinement, ~0.5g of each will make a decent noise. 2" square of paper wadded up with the powder in center, fuse sticking out. I thought it was going to go woosh... It did not. Last time I played with that kind of composition( before I registered here, so been a while). Neighbors, heat, low humidity here.. just better not.

Miles and miles of dry grass/star thistle = I like my freedom and $ right where they are.

DubaiAmateurRocketry - 12-6-2016 at 23:08

Quote: Originally posted by minstarmin  
By the way, I ran a thin fuse through the cap of the bottle with a hole drilled so the fuse would fit tightly. Maybe if you just run the fuse through the open mouth of the bottle, it would create more of a rocket effect? Aden


Depending on how finely grinded/mixed your mixture is, usually its unlikely to create more of a rocket effect, for a plastic water bottle, would just blow up. Take care.