Water Gun Adaptation



We modified battery-powered squirt guns so they can be operated with a switch. This way, kids who have trouble operating the trigger can soak their friends with a squirt gun, too!
Supplies
Here is a link to the squirt gun we used. Squirt guns come and go on the market pretty regularly, so you probably won't be able to get this exact squirt gun. However, the basic process outlined here should still work.
Materials
Solder
Electrical tape or heat shrink
Cable tie
1/8-inch mono female switch jack
Tools
Phillips Screwdriver
Wire strippers
Soldering iron
Remove Screws From Gun

Open up the squirt gun. If you can't get the squirt gun we used, make sure the squirt gun you get is put together with screws so you can open it without breaking it.
Prepare the Switch Jack



You need a 1/8 inch mono female switch jack with two wires. The easiest thing to do is to get a female-female cable, cut it in two, and then strip the wires.
Create a Hole in the Squirt Gun for the Switch Jack Cable





You need to create a hole in the body of the squirt gun to feed the switch cable into. I used a soldering iron to enlarge one of the screw holes. You will also need to cut down the part on the other half of the squirt gun that lines up with the screw hole to leave room for the cable.
Disconnect the Button That Activates the Squirt Gun


Disconnect the button from the cables that connect it to the gun.
A more ambitious modification would be to keep the connections to the button and add the switch-jack connection.
Solder the Female Jack to the Squirt Gun Wires





Connect the female jack to the cables that used to be connected to the trigger button. Insulate the connection with either electrical tape or heat shrink.
Use a cable tie to provide strain relief for the cable inside the squirt gun.
Re-assemble

Put it all back together!