It all started innocently enough. I was in a production of a Midsummer Night's Dream, and it was decided that for this production the cast party would be a water fight. Mind you, the only other thing I had that counted as a water gun was a small spray bottle that leaked a lot and had a range of about 7'. So my words on the occasion were, "If I bring a water gun, I will build if myself."
And wouldn't you know it, I did.
This is a powerful water gun, make that cannon, capable of delivering over a quart of water 25' or more, and due to its dangling hose design your reservoir can be as large as you want (I use a 5-gallon bucket). However, that same feature makes it cumbersome to carry around while in use; I just intended it for it to be stationary. All the parts are available for about $60 from Home Depot, and probably from Lowe's, although some parts were only available through the Home Depot website.
Step 1: Acquire Parts
2' of 2" PVC pipe
I believe this size is available precut in 2' lengths. But get 10' , this is mighty handy stuff.
2" of 1-1/4" PVC pipe
This is the first time I've ever had to use this size, so I got 2'.
2' of 3/4" PVC pipe
Alright, get the 2' lengths if you have to. But get 2 of them, as you'll need more for the connector tubes.
~1-1/2" of 3/4" PVC pipe (4)
For use as connector tubes. Length isn't critical.
3/4" PVC slip tee fitting
3/4" to 1-1/4" PVC reducing bushing
1-1/4" PVC coupler
1-1/4" PVC end cap
FRONT END PARTS:
2" PVC slip tee fitting
2" to 3/4" reducing bushings (2)
This part does not actually exist, so use whatever combination of fittings you have handy. I was going to use 2" to 1" and 1" to 3/4", but I ended up using 2" to 1-1/2", 1-1/2" to 1", and 1" to 3/4".
3/4" PVC end cap
3/4" PVC threaded adapter
A small (1" wide) hoseclamp
REAR END PARTS:
2" PVC threaded adapter
2" PVC cleanout plug
3/4" PVC in-line check valves (2)
More about O-ring sizing later.
5/8" to 3/4" FPThose barb fitting
5/8" ID tubing
I used 5/8" ID by 7/8" OD clear vinyl tubing. It comes in 10' lengths; I used the whole thing.
(Note: never fear, these parts will be shown later on.)
TOOLS AND SUCH:
Extra coarse, medium, and fine
Coarse round file
Or rotary tool
Drill, bits, and Unibit
Vise (or clamps)
PVC primer and cement
If you don't already have these, get the clear kind of both if available.
Thread sealing tape (Teflon Tape)
Electrical tape (if necessary)
Grease (Vaseline works)
Spray paint (or acetone)
Step 2: Dry Fit
Step 3: Modify the Cleanout Plug
Step 4: Modify the End Cap
Step 5: Start Solvent Welding Stuff
Cement the 2" tee onto one end of the cylinder and the 2" threaded adapter onto the other, then the 2" to 3/4" bushings in the tee, then a 3/4" connector tube in the bushings. Now cement the check valves in place, and no, I will not forgive you if you cement them in backwards. There's an arrow on each valve to make it easier. Next is another connector tube in each check valve, followed by the end cap/nozzle on one and the 3/4" threaded adapter on the other.
Now onto the piston: cement the 3/4" tee onto the piston rod, then (and this is the important part) slide the modified 2" cleanout plug over the piston rod before cementing anything else on the end. Now cement the 3/4" to 1-1/4" bushing onto the piston rod, then the coupler, then the 2" of 1-1/4" pipe, and then the end cap, leaving a 3/16" gap between the coupler and end cap. A 3/16" metal rod can help with this. Set everything to cure overnight.
Step 6: Finishing
Step 7: O-Ring Installation
Step 8: Tubing Installation
Step 9: Add a Filter
Step 10: Use It
Usage is quite simple: pull to load, push to fire. Remember, kids, safety first: don't shoot people who don't want to be shot, and don't shoot people at close range. Other than that, have fun!
P.S. It turns out everyone else at the cast party had squirt bottles similar to mine. Go figure.