I first saw a CO2 gun on YouTube where somebody was using it at a night club to spray down the crowd with a chilling fog. I knew instantly I had to try to build one to use at the Science Magic Shows we put on at elementary schools. I didn't realize how difficult it would be to figure out how to build the cryo gun - I searched for weeks and never could find plans online. So, I decided to figure it out on my own and committed to sharing the process for any other people who might be trying to find plans to make one as well. So, get out there and build yourself a cryo gun! Or, you can buy one (here) and save your self the headache...but what fun would that be!
How to build a cryo gun
Supplies: (links to Amazon)
The CO2 Cryo Gun Assembly:
CO2 Nut CGA-320 (kit w/nipple)
CO2 Nipple CGA-320 (kit w/nut)
1/4 inch Copper Tubing (find best price at local hardware store)
Flexible Pigtail 1/4" NPTF (pressure rated above 1000 psi) or High Pressure Hose with Regulator Connection if using a regulator. [These two products were recommended by other users. The hose I used is not available online. Use these hoses at your own discretion and risk).
CO2 Tank with DipTube (Must use liquid CO2. Paintball canisters will not work)
No DipTube? Just turn the tank upside down so the liquid comes out the valve.
CO2 in Tank - Where to fill? Check at local welding supply or brewing supply store.
There are several options for your Cryo Gun backpack. I've included information for making your own CO2 backpack and links to purchase backpacks specifically designed to carry CO2 tanks.
Pack Frames (three options as shown on Amazon.com).
Aluminum Pack Frame with Freighter Shelf *Recommended because it has a freight rack which allows bottles to be carried upright or upside down depending on whether you purchase a dip tube tank or standard tank*
A.L.I.C.E. Pack Frame (Light Duty)
CO2 Backpack (Designed to carry CO2 tanks. The downside is the cost.)
Tie Downs to Secure the Tank to the Backpack
How to assemble the CO2 Cryo Gun
All instructions for assembling the homemade cryo gun are included in the video above.
CO2 Cryo Cannon featured on The Science Spot on Montana This Morning - CBS