This is a Water Gun made of PVC pipes and some brass fittings.
I made it such that it can be disassembled for storage and assembled again when required.
The 4 parts its made up of are
- Air tank (i made it detachable such that i can be used for another similar project)
- Water Tank (we can use any size regular cold drink bottle, but based on my test during development, i realized it can empty a 2.25L bottle completely just with the stock air tank)
- Gun T Section (this parts joins Air tank, Water tank and nozzle together)
- Nozzle (i over did this part, you may just use small brass nozzle or car wash hose nozzle instead)
How to operate
These are the steps below
- Make sure the air tank valve is closed.
- Fill air in the air tank through air inlet valve. For this pupose i went up till 100 psi (6.89 bar)
- If not done yet, then attach the air tank, T section and nozzle togetherAttached water filled bottle to the gun
- Aim and fire (open the air tank valve)
How it works
As shown in 'Fluid flow diagram', when valve is opened, air goes in to the bottle through a thin pipe. As air is introduced in the air tight bottle, pressure builds up and water raises though the tube and bursts out through nozzle
Step 1: The Air Tank
- Choose a correct tank
- Make sure its a steel can, so that we can comfortably solder it
- Bigger the can, the better. (i chose an air freshner can)
- Make Holes for Connections
- Can's top end i used as an air tank extension, and attached the end cap. (used a rubber washer to air tighten it)
- Can's Rear end is used to attach the brass valve. (at both the ends of the brass valve, i inserted silicon washers to make the attachment air tight)
- Added one hole for the Pressure gauge (used a silicon washer here as well)
- Last one hole for the tyre valve to fill the air
- See the pictures for a reference
- I used a female connector to solder the air tank to, and used male to male brass coupler to attach it to valve
- please please please be extreamely carefull while doing this
- Start testing for low pressure first (i started with 25 psi)
- gradually keep increasing the pressure
- These tests will not only confirm solder leaks but joint leaks as well, since major parts are connected and air tightened using silcon/rubber washers.
- I went up till 100 psi
Make sure you solder work is as clean as possible. I recommend using a blow torch to make sure the solder is evenly spread. My initial attempts using very basic 25 watt soldering iron resulted in air leaks.
Step 2: The T Section
- Make an air tight seal around air tube, that will carry air to the bottle
- Insert a vynil tube along with conical washer (add additional disc washers to have more space to tighten). I additionally used a brass tube to tighten it properly in the pvc connector
- Let it pass though PVC T connector.
- Use a PVC pipe connector to attach a small 6 inch pvc pipe segment to the T section which we will attach water bottle to.
- Get a cold drink bottle cap and make a hole though it wide enough to slide the pvc pipe through it.
- Slide the cap to the way up till it sticks to the PVC connector at the top
- Glue it firmly with the best glue you may get :P, since it should carry 2.5 L bottle filled with water
- insert a small washer in the cap to make sure when we attach a water bottle, it forms a water tight seal
- Take out the other end of the air tube from a hole on the PVC pipe segment
- make a small hole just enough to fit the vynil tube
- Peek out the tube from that hole, glue it firmly right there
- slice off the excess tube, file it to make the surface even as rest of the pipe so that water bottle can slide over it
- Attach flexible rubber tube to the other end of the PVC pipe segment
- make sure the diameter of the rubber tube is no more that the PVC pipe and its thinner enough to bend according the height of the bottle
- file 3/4 inch of that segment to fit the ruber tube nicely still not being bigger the the PVC pipe diameter
- Glue the rubber tube to the PVC pipe firmly
- Repeat the pressure testing performed in first step, this time with a bottle attached
- attach a spare PVC end cap to the nozzle part of the T section, so that leakage in the assembly can be monitored
- you may use a smaller bottle for this purpose
- you also might want to keep the bottle filled with water to inspect the bubbles, additinally it will also reduce the air volume that is compress, so its safer.
Step 3: The Nozzle (the Over Done)
Let me accept the fact that i got carried away with this. I wanted to make a laminar flow to increase the range of the water gun.
The quickest and easiest way to make a faily well nozzle is to attach simple PVC pipe end cap with a hole in it
Another better way would be just attach a brass nozzle used for gardening.
I am still putting the steps just to know your views on this.
- Started with a PVC female connector so that it can be attached to the T section
- Added intermediate PVC pipe segment to extend a little bit
- Added 0.5 in to 0.75 inch expander connector
- Inserted 0.75 inc PVC pipe segment with a length 2 inches
- this is the section i am indicating with my hand in the picture bove
- this is the section we stuff all our scoobie strings
- attached another 0.75 inch to 0.5 inch reducer to the other end
- attach conical ruber gasket to reduce the water flow area
- attach a ballpoint pen body make water flow more pointy
- Glue this whole assembly with epoxy or similar good quality water proof glue
Additionally we may (should) attach yet another pvc ball valve to have a finer control over the water flow.
(sorry guys for not uploading a video of this gun in action, please follow this project as i am planning to do it ASAP)