Loadingā¦
12
I tried to build a potato cannon from memory and it backfired in my face, now I have a safety question
Last weekend I put together a potato cannon using a 4 foot PVC pipe and a can of Aqua Net hairspray, just like I did back in high school. When I fired it, the back cap blew off and hit me in the arm, leaving a bruise the size of a softball. Turns out the cleanout plug I grabbed from my garage was rated for drain pressure, not combustion. What's the right way to pick a pressure rated plug for something like this, and is there a chart somewhere?
1 comments
Log in to join the discussion
Log In1 Comment
brianellis1d ago
Learned the hard way that the plug is the part that actually matters here. I used to grab whatever threaded cap fit and call it good, but after seeing enough of these blow apart I only trust PVC fittings stamped with a pressure rating like NSF-PW or SCH 40 with a PSI number on it. Drain caps and test plugs are made for water sitting still, not for a boom going off inside a pipe, so the threads strip or the whole cap rockets off like yours did. There is no single chart for potato cannons since they aren't a real product, but you can look up the pressure rating tables from the pipe maker and match the cap to the pipe's rating. Grab a threaded cap made for pressure, not a cleanout plug, and if you can't find the PSI stamp on it, leave it on the shelf.
6