Things You'll Need
Instructions
Get a used spray bottle such as one used to hold window cleaner and clean it out. Rinse out the bottle, then fill it up with water and squirt water out of the nozzle until there is nothing but water in the bottle.
Cut the bottom two-thirds of the bottle off with scissors. This is going to be the tank of your mini water gun. Make it bigger or smaller depending on how small you want the gun to be.
Cut the tube so that it is slightly shorter than the section of the bottle remaining. It should come down to near the bottom, but not push against it.
Cut a square of plastic the size of the hole in the bottom of the bottle. Glue it to the bottom with epoxy. Wait for the epoxy to set. You now have a mini water gun.
Add some rubber cement to the outside of the joint. This can help protect against leaks.