Step 6: Troubleshooting

Picture of Troubleshooting
Okay, so you're losing air pressure in the pressure chamber. This is because you've got a leak somewhere. No matter how much PVC cement you used, leaks are usually inevitable. But there is only one part of the air cannon that they're found at-the pressure chamber. To seal them, you have to find where you're losing pressure. There are methods to finding air leaks that range from simply listening for a fizzing noise and trying to find it that way, by coating the pipe with a film of soapy water and looking for the formation of bubbles due to escaping air, or even submerging the unit under water and looking for streams of bubbles traveling upwards. All of these methods work with different results. It's how you seal the leak that matters. Any other weird problems, please leave a comment southward on this instructable, and I'll see what I can do.
X3R01174 years ago
Couldn't you wrap the pressure chamber in duct tape so that 1. air doesn't escape as easily and 2. even if the chamber does explode, the duct tape would take most of the force.
eyebot117 (author)  X3R01174 years ago
Of course. However I'm not positive that will prevent the air from escaping. Unfortunately, duct tape will not take most of the force from a rupturing pressure chamber. For one, the chamber would have to be under immense pressure for it to rupture to begin with (we're talking 200 psi-ish, but it depends on the size of the pressure chamber), which should it explode-the duct tape may only help prevent a certain amount of shrapnel from peppering your body. The pressure chamber would still explode nonetheless.
I have seen people wrap their pressure chambers in chicken wire/wire mesh for the sole purpose of containing shrapnel, but again-pressure chambers are DANGEROUS!!!!

That being said- NEVER over-pressurize your pressure chamber, ALWAYS treat the pressure chamber with extreme care (as you would any firearm) when under pressure, and ALWAYS use schedule-40 Pressure-rated PVC pipe when building PVC pressure chambers. It's also never a good idea to leave it under pressure when not it use as this can weaken the chamber as does cold temperatures.

However, the tape always gives things a nice look anyways and there's no harm in wrapping your pressure chamber in duct tape.