The Ultimate Water Gun. Grab some pipe clamps, high pressure hose and epoxy and you’ll be well on your way towards building a Fireman Sam style water pistol. Soak ‘em? Drown ‘em, more like.
- Open the stop valve on your gun, and close the ball valve. Unscrew the cleanout cap on the tank.
- Fill with water through the 1.5″ port on the Tee.
- Replace the cleanout cap, making sure it’s on tight with a wrench.
- Attach the air compressor and charge the tank to 85 psi.
- Put the backpack on your back, or otherwise make sure that the tank remains upright throughout firing.