Sciencemadness Discussion Board

silver fulminate and magnesium powder

deyehaus - 31-5-2015 at 17:50

First thread! wooo

I am planning on brewing up a few grams of silver fulminate, I realize it isn't one of the safest explosives but i have been hard pressed to find other effective impact detonators. I checked before hand and I was unable to find if the temperature created by detonation is enough to ignite magnesium or if i will need to add another "stage" to the mixture such as potassium chlorate?
As an afterthought does anyone know a way to safely store silver fulminate?

PHILOU Zrealone - 1-6-2015 at 10:03

Ag fulminate and Mg...
Considering the electropositivity of Mg and the oxydo-redox potential of silver...you get a kind battery in shortcut:
2 Ag-O-N=C + Mg --> Mg(-O-N=C)2 + 2 Ag + heat
So probably not the smartest thing to do --> or spontaneous, or by air humidity, it may self heat and decompose explosively.

Silver fulminate is really very sensitive, the best way to store it is flegmatised, dextrinated, in tiny quantities separated from each other...sometimes glued inside a hard matrix.

You know those crackers that you have to pull each side of a tiny rope...the friction of a loop of the rope on a few grains of Ag fulminate makes the thing go boom.

It is also used in snap it everywhere bangers, the tiny silk paper bags with 3 to 5 sand grains coated with Ag fulminate.
By pressure between fingers, walking on it or trawing it against a hard surface, despite the multiple layers of paper it goes boom. In the past I used to boost those up by carefully opening the bags and adding some 10-30 mg of silver nitrate acetylide complex and there you get really a big detonation fireball of 30 cm diameter (avoid doing this Inside if you like your ears...) and treat with very great care!

Bot0nist - 2-6-2015 at 07:00

I was under the assumption that the pull string prank toys were a string shaped like an "S" inside a paper tube, and coated with potassium chlorate and red phosphorus, making and detonating an Armstrong's mix when the string is straightened, and the string rubs against itself inside the tube. I have made some myself like this, using duct tape as the tubing and coating segments of the string in chlorate and phosphorus. About every other one worked, if the string was pulled rapidly

I can attest to the little rock filled poppers being powerful in mass. We regularly used to carefully empty dozens of them into the corner of a plastic bag, and make one large popper. The bang when it is dropped or thrown is startlingly strong and deafening.

Hennig Brand - 2-6-2015 at 09:20

I have also read that silver fulminate was or is used in those.

I have also been told by a fireworks maker, that the most common composition (the only one he has seen) now used for those pull string bangers is a mixture of potassium chlorate and arsenic sulfide.