I began by looking at a few places online, and right here on instructables for some ideas. I found the water mortar (part one and part two), and the waterzooka instructables very helpful.
With the basic idea of a piston/barrel-type water gun in mind, I wandered around the hardware store for a while until I came up with the following design.
I made a lot of these, and individually the guns ended up costing around $5. It'll cost you more or less depending on a number of things, of course.
They are tons of fun, and we get them out on a regular basis for family water fights. Thanks for looking. I hope you find this useful!
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Signing UpStep 1: Supplies
From one 10-foot length of PVC of each of the above mentioned sizes, you can make four 30-inch water guns or six 20-inch guns. The 30-inch guns are best for older kids and adults, whereas the 20-inch guns are easier for little kids to handle. Either way, the design is exactly the same.
This design is pretty simple and easy to mass produce. However, certain parts may be tricky to find. I had to check a couple of hardware stores before I found all the pieces to make this work.
In addition to the pipe, for each gun you will need the following:
- One 1 1/4" PVC end cap
- One 3/4" PVC plug
- One 1 1/2" rubber washer, with inside diameter near 1/4" (and it must be real rubber, not neoprene)
- One 1 1/4" fender washer, with inside diameter near 1/4"
- One 1" by 1/2" 90-degree elbow, or similar (see below)
- One 3/4" #12 pan head screw (or something similar that works)
There are a couple of options for the 90-degree elbow, which will become the handle. I had plenty of 1/2" PVC scrap, so I got some 1" by 1/2" 90-degree elbows, and attached a small piece of 1/2" PVC to make the handle. You could use a regular elbow, or a cap instead, but I like the look and feel of the 1/2" handle.












































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so then (still in instructables mode) grabbed the pump from the end of my broken premade watergun and found a small length of pvc in a neighbors recycling bin
(shh! don't tell anybody!!) but with the pipe and the pump handle i just needed an endcap... fortunately for me I constantly carry a credit card with duct tape rapped around it, using a pen ink cartridge as a mold I put about a half inch of duct tape around it with a piece of paper in the center (to make the duct tape not stick to the pen cartridge) i took the small duct tape roll with a hole in the center and put in the front of my pvc pipe with the help of some more duct tape and there you have it. an extremely ghetto water gun...
btw i only said duct tape 4 times and sorry for any grammatical errors
You don't really need the right angled handle; you're likely to brace the butt on your hip anyways (more range!), and if you push too hard on the right angle handle, it'll break. Saves a buck or two on the fitting, too.
Seals run the gamut, from rubber (as shown) to old-fashioned "leathers"--made of real greased leather (take apart a bike pump to see what I mean) to o-rings. O-rings are best, but require machining. You *can* do this by hand, with a small file. Chucking it in a drill and using a hand-held file works, too. We generally use 2" outer tubes, which, at 30" will hold about a quart of water. These are best used in pools or from boats, since the refills are nearer. ;-)
Capture The Flag is pretty fun, too. The "flags" are 5 gallon buckets--with trickling hose end inserted to keep 'em full--for filling the guns, of course!
If you get seriously fun, safety glasses are a nice thing, though if you hit them juuussst right, you can flip them off your opponent's face with the water stream. Harder to attack face/eyes if you wear a brimmed hat.
What I'm looking for now is a cheap and simple "laminar flow device" to increase range. In the meantime, chamfer, smooth and polish the "muzzle" hole to try to keep the water stream intact. If you make a bunch of guns, mark the ones with the best range, and make sure your "guests" get unmarked ones! ;-)