WaterWar.net

I'm very new to this, but decided I wanted to build a river canon that could be used to launch water (non balloon) distances without using gas or electricity, think human power. I purchased a plastic firehose nozzle from McMaster-Carr ( 6424T62 - 1-1/2" Size, Npsh Thread, 71 Gpm @ 100 Psi Plastic Quick-flow Stream Nozzle ) since this was clearly a necessity to keep the stream from breaking up. I envision a tube dragging behind the raft to draw in water as needed, but I am not sure of the best way to presurize the entire system. I looked at modding a sprinkler valve ( http://www.spudfiles.com/forums/viewtopic.php?t=305 ), thought about peddle power or arm power, but figured I would throw this one out to the experts since the rafting trip is only weeks away.

Searching the internet and this site did not get me what I wanted, only pieces with no real answer regarding power. So .... has this been done before and if so, would you mind sharing?

Thanks

Welcome to the site!

There are many different options for building your own homemade water gun, almost all of which are human power. However, the fact that you are on a river means that the best option would probably be a simple piston cannon (imo). Companies like Stream Machine already make reasonably sized tube-in-tube piston cannons. These require you to dip the barrel into a water source while refilling, but allow you much greater range in a shorter period of time than a similarly sized air pressure or constant pressure design. The only drawback is the need to lower the barrel while refiling. However, you can definitely modify the front of a piston cannon with a one-way check valve and a length of tubing that can drag into the water much as you described. This would allow you to maintain a constant elevation while refilling and firing.

Let us know how your project goes, and post pics of the completed design!

Soak On!

Thanks for the quick response ....

Interesting comment that might solve the problem. For maximum speed, would it matter where I place the check valve? Also, is this valve something easily purchased at Home Depot or is it more specialized?

Jeff,

I haven't found them at my local Home Depot, but they are readily available at Lowes if you have them in your area. Otherwise, you can purchase them online (they are fairly inexpensive for sizes under 2").

Here's a quick sketch of what I mean:



The direction of the check valves will be dictated by the flow of the water.

That's a great idea for a river cannon. Maybe a Stream Machine could be modified like this.

I've talked about this all the time but never actually scribbled together an image for it until now.



Would probably work better than a piston blaster but takes more work to do. Also, for the piston pumper, you'll want to use a low-diameter pump or you'll end up with pretty much useless results. Higher diameter pumps require a lot more force to operate, and consequentially, you don't create as much pressure on the water. The end result is useful for filling Super Chargers and water balloons but can't shoot worth crap. Higher diameter pumps however, are okay for foot pumps because they can pump in more volume at a time. However, you can also choose to sacrifice pumping volume for sheer power, and end up creating a pumpable blaster that's considerably more powerful than any standard water gun. It'll take a long time to pump, but it'll shoot a bit farther.

Stream Machine sells an adapter for this. It is called a Boat Buddy. It cost about $11 plus shipping. Check it out.

Wow, I had no idea that something like that existed. Thanks for the tip, Bopper!