Instructables
A few years ago I wanted to buy a bunch of water guns for a summer picknick that was coming up. I looked in the local retail store and there were no Super Soakers to be found. So I became determined that I could build my own water gun. After realizing the complexity of a Super Soaker and the cost to build one out of PVC I simplified my design into what it is now, The Water Hand Cannon.

*I must give credit to some of my inspiration. First was an Instructable on building a Water Mortar.
*My next inspiration was the commercially available Stream Machine that i found at an outdoor sporting store.

The following Instructable will outline the steps to make your very own Water Hand Cannon that will out soak all those Super Soakers.
 
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Step 1: Materials


Materials Needed:
  • 1/2" Schedule 40 PVC
  • 3/4" Schedule 40 PVC
  • 1" Schedule 40 PVC
  • 1/2" PVC End Cap
  • Two 1" PVC End Cap
  • 45o 1/2" PVC Elbow
  • PVC Primer and Cement - Clear
  • Two #15 O-Rings - 1"OD X 3/4" ID -> These can be found in the faucet repair sections of your hardware store


Tools:
  • Engine Lathe and Tooling
  • Hacksaw
  • 1/4" Drill
  • 7/8" Drill or Foster Bit
  • Deburring Tool
  • Petroleum Jelly
  • Small Scrap Piece of 1/2" and 1" PVC pipe for checking fitting -> 3 to 4" is fine

A bit about size:
Each gun I constructed is about 2' long when collapsed. Smaller guns can successfully be made. I have two 1' Water Hand Cannons that work very well for smaller children and still have the same range as a full size gun. Any smaller then a foot would have a limited water reservoir and be hard to thoroughly soak your victims.
On the opposite side I did make a 3' gun with the hope that the extra foot of water would be an advantage. I found instead that the gun was hard to hold when it is so long (6' filled) and was prone to bending due to the soft  PVC. Anything around 1 to 2' is the perfect length.

A lot about tools:
Unfortunately for some I make extensive use of the engine lathe in building the Water Hand Cannon. I imagine the parts could be turned down using other methods that I have seen on Instructables but using an engine lathe greatly reduces time and will make it easier when making multiple Water Hand Cannons. (Yes you will want more then one for a proper water fight.)
For turning down the PVC I used a round nosed HSS bit. The radius on this bit is about an 1/8th of an inch. By using a round nose bit the finished part will have a much smother finish. This radius also closely matches the needed radius to make the o-ring groove. To make this bit i took an 1/4 inch piece of HSS and added the radius on the end. After having the proper radius I then tilted the grinding wheel table to add the front clearance angle. For cutting PVC a back rake angle is not needed but if you are planing of using the tool for rouging out metals you will want to add this angle while you are making it.
Another operation in this Insturctable calls for a boring bar. You will want one that will be able to clear a 1/2" or smaller hole. The style of baring bar is up to you as long as it gets the job done.
Construction of the nozzle and retaining cap call for a tale stock and drill chuck along with the appropriate drill bits.
That looks great, from building spudgun pistons ive learned decent grooves can be made by using a files and elbow grease, or the side of a drill bit while you slowly rotate the pipe.
where do you get the o-rings?
seamster4 years ago
Hey, these look pretty good!

Have you noticed any issues with vaseline eating up the rubber o-rings? I initially used vaseline on my water guns, and it seemed like it was slowly breaking down the rubber washers I used. Since posting my i'ble on water guns, I've made a couple similar to yours with o-rings, and I have to say I like the o-rings better. They take a little more work, but they seem more durable and reliable.

Anyhow, good work!
LeumasYrrep (author)  seamster4 years ago
No I haven't noticed that the Vaseline eats the rubber. It does tend to collect a lot of dirt. When I cleaned the ones I had made two years ago the dirt and grime was packed into them. The O-rings do take a lot of work where your design was much faster looking. To finish all ten of mine it was about a day after collecting all the materials. There was also a good amount of time trying to remember how I had constructed the first set of guns. That was my main reason of posting an Instructable so that the next time I make some more I don't have to waste time remembering how they where constructed. Thanks for looking.