need advice for making a very custom water gun

[CROC]

Your plan for a cutoff switch as a secondary safety should work wonders if you are concerned at any point with the pressure chamber bursting due to pressure. In fact on that nerfhaven link on the first page, the guy did something very similar, which was put a switch in there that is normally closed, and then opens on a press. The only required wiring you would need to do would be interrupting one of the wires from the battery pack to put the button inside your PC case.

[neogeo]

Yeah, I'm definately going to wire in a cutoff switch when I get the time. In fact, I don't know why I didn't do that to begin with. It probably would've saved me a ton of frustration and headache concerning the pressure of the system.