7 replies to this topic

[cat]

I was asked some questions about indoor pyro special effects and I realized beyond some simple stuff I really haven?t looked into this area. Does anyone have a good web reference for indoor pyrotechnic comps?

[alany]

I've never seen any online resources for indoor compositions. Indoor pyro is almost exclusively commercial stuff for obvious reasons! But most devices seem to be based on nitrocellulose or ammonium perchlorate to keep the smoke down. Indoor isn't really my bag, and I've only done a few shoots, anyway...

I have some commercial misch metal fountians (the cake fountians from Skylighter) that contain fluffy white nitrocellulose cotton with a small amount of misch metal spread through it. The stuff is just pressed into a 3/8" tube about 4" high with a pink glassine drumhead over it. Only about 3" is filled with composition, there is a thick clay plug about 1" in, probably to ensure the end with the spike remains fairly cool.

Some commercial indoor colour torches I've used are similar, the base is definately some fluffy form of NC but I am unsure how the colouring works. They do produce a bit of fine white smoke and quite a bit of black dross that tends to collect on the e-match remains if you aren't careful matching them. It could be something as simple as a metal chloride dust mixed with the NC?

I assume the saxons and gerbs I've used are AP based. They are almost smokeless but the composition doesn't seem to be NC, it is grey black like BP with titanium in it. It might be some form of NC I guess, but there isn't the big orange smokeless flame typical of NC as it burns. I doubt they'd use AN.

The flash kits available seem to be just the usual 7:3 white flash or the coloured flashes you can find anywhere. They aren't low smoke at all. I am unsure if the concussion flashes are Mg based, or just fairly hot Al based flashes.

I'd say Titanium, NC and Flash are the basic ingredients for most indoor stuff.

[cat]

I've never seen any online resources for indoor compositions.  Indoor pyro is almost exclusively commercial stuff for obvious reasons!  But most devices seem to be based on nitrocellulose or ammonium perchlorate to keep the smoke down.  Indoor isn't really my bag, and I've only done a few shoots, anyway...

This all started from a TV show a few nights ago where a stage-pyro device started a fire in a club. I was asked what the effect was produced with. The effect was quite impressive with a 5foot red-orange flame and considerable sparks. My interest is purely academic; I hate to answer any question with ?Sorry, I don?t know.?

Alan: I?ve been researching this topic since last nights post. I spoke with a retired employ of a major supplier of stage-pyrotechnics (he requested the co name to be omitted, and since I can?t confirm his statements take this as his opinion, not fact). Surprisingly his clam was that most of the comps used for indoor effects are the same as standard consumer ?fireworks?. What was particularly perplexing is that chlorates and barium compounds are somewhat common (though my understanding is that chlorates have been banned in stage-pyro), apparently they get around this by selling a binary mix.

NC surly is the most common binder but not necessarily fuel as BP is commonly used. To me this seams unacceptable, but what do I know. He also mentioned that many pro use a few types of smokeless powder mixed with coloring agents, nitrates and metal fuels to produce a wide range of effects.

I DO NOT recommend this practice!

[PyroKid]

With regards to indoor pyrotechnics / special effects ....

I work as a technicien for a local theatre group.

We use pyrotechnics in a number of our shows.

As someone mentioned in this topic earlier on, the majority of pyro used indoors is commercially produced.

I for one would not be willing to produce a device for indoor use.
Remember that the risks involved with the use of pyro in a close proximity / enclosed setting are greater than when used in an outdoor setting.

The very nature of the use of indoor pyro often means that there will be people (cast, crew, audience etc) within a few feet of a functioning device, and therefore strict specifications need to be adheard to in the production of such devices.

Not only this, but it is also necessary to ensure that all fallout has cooled before coming into contact with any surface, and that all flamable material within the vecinity of the functioning device (see safety data sheet) has been coated in a flame retardant coating.

As someone mentioned earlier on, these devices often produce a large ammount of smoke, so make sure there is adequate ventilation before considering such devices, such as ensuring that all fallout has cooled before touching

For more information, point your browsers at the following URL:

LeMaitre

Edited by PyroKid, 07 January 2005 - 05:56 PM.

[cat]

I for one would not be willing to produce a device for indoor use.

I would agree with this statement as safety should be paramount however as stated above ?My interest is purely academic? and I haven?t found much information on the subject. I?ve ordered a book it should arrive in a few weeks, if there is anything substantial I?ll follow-up.

[Creepin_pyro]

Indoor pyrotechnics are left strictly to the professionals for good reason. I believe there was an ealier thread that discussed this.

It's one thing to have a homemade shell flower-pot with spectators far away enough to be safe, but building a device that is to be used in close proximity to people is insanity. Commercial indoor items go through exhaustive testing before they're approved for use.

HFM have a wonderful range of stage pyro - there's no need to go building your own.

[cat]

ADMIN: How do you delete a thread or close a topic?

I dont think anything useful will come out of this topic.

[adamw]

I have worked for 2 years for a manufacturer who made stage pyro. Suprisingly a lot are made using BP based compositions with titanium used for sparks. Some, such as 'flame projectors' are based on smokeless powder. Smokeless fountains aren't used much. BP in a small stage jet / gerb doesn't really give that much smoke at all.

And I will close the topic.