flash pots...only not

[egorleski]

So were doing les mis in a theatre where we cant us flashpots. that makes the baricade considerably more difficult. I was thinking of using somthing small like film canisters filled with something like sawdust and then compressed air/co2 to get the look like bullets are hitting the baricade. Anyone every try somthing like this? any ideas for a good material to blow out? i feel like saw dust may just make the stage more slipery then we want. I have been toying witht he idea of some metal shavings so it will catch the light or maybe using a slightly more corse wood shavings...

Thanks

[koncept]

what about compressed air and glitter in fim cases... that would sparkle and catch the light, toss in some saw dust with it. that might provide you with the "fire" part of the bullet and the "hit" or one...

[sound_nerd]

I'm very interested in this as well....I'll be keeping an eye on this thread! I need something along these lines in a larger format. My original idea was large PVC canisters piped with compressed air mixed with a compressed fog. The trigger system I've been working on is dmx based with electronic air solenoid valves.

[Footer]

I did a very simular thing about 6 years ago for a show. We needed halfway realistic pyro without doing live fire. What I did was cut 5/8 PVC tubing to 1' pieces then put a 1/2 barb on the end. We had a raked floor that we could drop these tubes in. They were plumbed with 1/2 hose up to a patch that we could patch them into 6 cylonoid valves (we had over 30 lines). The valves where fed at 140 psi via a nitrogen tank. The tubes where filled with a mixture of shredded mylar and talc powder. This system was rather easy to build and to set up (we set it up and loaded it in 30 min at IHSTF).

[egorleski]

questions for footer: Why did you go with talc powder as opposed to a saw dust or similar? does talc give u better traction or just available cheap? Talc scares me a little in the whole maybe it causes cancer we dont really know aspect. Hopefully the exposure would be minimal and it probably wouldn't matter but i doubt its really even worth the thought.

second why nitrogen? just couldn't get the pressure u needed out of an air compressor?

While were on this whole concept... anyone ever use this same technology to make guns that fire safely on stage? i could see installing a c02 cartrige to stage guns and just blowing out a little saw dust like the gun is actualy firing... thoughts?

[Footer]

Saw dust is not fine enough to give a realestic smoke cloud, also you REALLY dont want to even think about breathing it. What we did was pack the tubes nearly full of mylar then put a dash of baby powerder on top. The reason i went with nitrogen was to get the pressure up. The valves i had where rated at 150psi (and would lock up at 160). The most you can get out of an air compresser is 110 max, and you have to deal with putting the compressor somewhere that it can recharge and NOT be heard. The nitrogen gave a sustainable volume of air over a long period of time and that extra 30 psi gave me about 3' more of a shot. If I was back in my apt. I would have some pics to send to you, but I am not, but will be in 2 weeks. I can post some pics of the setup then. Also, where do you hear that talc causes cancer? Everything these days causes cancer!

[koncept]

i have used some air compressors that last for awhile and get higher than 110, are you sure that was not a limitation of your regulator/compressor??

[BillESC]

Is there to be no pyro at all?

We've created realistic bullit hits using squibs (electric matches.)

Common the neutral side together and bring the hots individually back to a nail board. Swipe the nail board with 12v and you can rake the stage with machine gun hits.

[egorleski]

Everything these days does cause cancer... at least in california. they say talc causes ovarian cancer and causes lung cancer in rats and evidence in humans is not conclusive. I think maybe a fine flour then may be best. if it is fine enough to get a good smoke cloud then you know it is edible and dont really have to worry about that then. I dont think we will be doing that many shots so i think that with a couple air compressors charged prior to the show and just not plugged in so they dont automaticaly recharge we should be able to do it. im also looking into the c02 route. in your system were u able to fire them individualy or was it a machine gun like effect with many shots in quick succession? once i get back to school ill make some mockups and start testing what things work best for what we are doing and post some pictures and such.

[jwl868]

When using compressed gas, be aware of the pressures involved. The compressed air (from a compressor) is usually only around 150 psig. Carbon dioxide will be around 800 psig. I'm not sure about compressed nitrogen, but I am under the impression that a full cylinder is at at least 2,000 psig. When using bottled/cylindered gases, you'll need a regulator, and you should give some consideration about how to prevent someone from changing the regulator setting.

The tubing, valves, and fittings what work in compressed air systems may be dangerous to use in higher pressure systems.


Joe