# Building Your Own CO2 Cannister.



## epicket1 (Jan 13, 2013)

I have a show coming up and I would like to know how to build my own CO2 canister that would shoot out fog. I can't afford to purchase one. If I tape up one end would it make a loud pop? I also would like it to sit on the ground and control it 10 feet away.


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## alyx92 (Jan 13, 2013)

Before doing anything involving special effects, weather it be pyro, Co2, or anything of the sort, it would probably be wise to contact a local professional who deals with this stuff regularly. It may not be the answer you wanted to hear, but it could save you a trip to the hospital!


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## Les (Jan 13, 2013)

Do you mean a Co2 (Cryo) jet? 

Co2 jets really aren't a DIY project, especially for a novice. You need high-dollar and _high pressure_ cryogenic parts (hoses, solenoids, etc), which is why they are so expensive. Any parts that are non-cryogenic can freeze and subsequently fail, potentially causing a very dangerous situation. Believe me, it is a lot of trouble and you will spend more making one yourself. Since these effects operate under very high pressure, it is absolutely not something you can cheap out on. Not to mention, Co2 gas can cause injury due to the sub-zero temperatures and the fact that it can cause asphyxiation.

I recommend renting a Co2 jet or using fast dissipating fog. Word of caution: most companies will not "dry-hire" Co2 jets due to the potential dangers involved. You will probably have to also rent the operator. 

Note: you will also have to rent Co2 tanks from an air-gas supplier. A 50lb tank (don't let that name fool you -- they weigh about 250lbs) is good for, oh, about 30 seconds and then it is depleted. Be sure to specify that your tanks need a Siphon Tube. The Co2 tanks for a soda fountain will not work. Paint ball gun Co2 tanks won't work either because A) your effect will be about three seconds long and B) it will be nearly invisible due to the lack of the siphon tube. 

As you can see, Co2 is a lot of trouble, even when you have all the right equipment. I highly recommend using fog instead. Trust me on this one. I deal with Co2 almost daily. We manufacture much of our own equipment but opted to purchase our Co2 jets from Sigma Services.


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## MPowers (Jan 13, 2013)

Do you want to build a device that makes fog like a fire extinguisher, or a dry ice fog machine for low lying ground fog? 

If the former, forget it, DON"T TRY THIS AT HOME!!!! Over the years I have built many cryogenic devices and FX gags using CO2, LN2 and Liquid air (80/20 N2/02), and I would never, ever even consider making my own cylinders. Think you can build a 853 psi cylinder with a 3:1 design factor? Besides, even if you built your own cylinder, you would still need special (a.k.a. expensive) cryogenic valves and gauges. In addition, I seriously doubt you could get any welding or medical gas supply to fill a home made tank.

If the latter, that's different. If you have moderate plumbing and electrical skills and knowledge, you can do it. CB has a number of threads on dry ice foggers.


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