theatrical concussion flash

[dave321]

not sure if this belongs in the HE section, if so please move

 

am i right in thinking most concussion compositions for use in a concussion mortar are based on

 

magnesium /strontium nitrate ?

 

or is 70/30 also used ?............is this more "explosive / noisy" than the above magnesium comp?

 

any reason the following comp could not be used as it is based on a reformulated military simulator mix ?

 

strontium nitrate 53.5

aluminium 40

sulphur 5 reduces ignition temp.

boric acid 1 counters potential nitrate aluminium reaction

cabosil 0.5

 

these compositions are design for noise not light.

 

i am aware that each manufacturer marries their composition for use in their own mortar for safety reasons

 

on a seperate note maybe the forum needs another section specifically for theatrical/stage /spfx pyro ?

 

dave

[bikemaster]

I use a lot of "Le maitre" and "NextFx" concussion type flash powder.I am pretty sure they use the 70:30 we all know, using potassium perchlorate and aluminium flake or magnalium.

The composition you just show content sulphur... this is not really good if you are doing a show in a theater and it start smeling SO2 after each concussion.

[Mumbles]

They generally come as 2 part mixes. I'd imagine shipping would be a pain otherwise. They're generally formulated so that they can be mixed by volume. I also believe they're a bit more tame than straight 70:30 with black Al, but that might just come from fillers/blends of materials needed to get equal volume compositions.

[dave321]

using 0.5g of each :-

 

std 70/30 gives a small thud unconfined

 

whereas

 

strontium nitrate 53.5

aluminium 40

sulphur 5 reduces ignition temp.

boric acid 1 counters potential nitrate aluminium reaction

cabosil 0.5 flow agent

 

is fast but gives no "thud" when unconfined, quite a "soft" flash.

larger amounts and confined, is of course another matter, i am sure it would perform as it were.

 

dave