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 Post Posted: Wed Jul 09, 2003 10:00 pm 
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Originaly posted by Harly,
I've put together ten or twelve pneumatics in the last five years mostly because combustion guns are loud as hell.

My last one had a six foot barell and six foot chamber with a single sprinkler valve. It put out some very good distance and was very quiet. The twelve guage blast going off next to your ear with combustion guns is just no fun for old guys like me. When I built that six foot gun I used threaded adapters on the connection from the sprinkler valve to the barell so I could simply unscrew the inch and a half barrel and replace it with a two or three or one inch for that matter. I didn't use tape on the threads so I could get it off easier. I never had a problem with pressure leaks. But when I first built it I decided to pressure test the gun with a full barell of water because water doesn't compress. I didn't have any leaks and managed to irrigate the whole yard when I pulled the trigger.

After I used a barell full of water to quiet down a noisy party going on next door a friend and I thought about how to improve it. In other words an UBERSOAKER no piddly little plastic kids toy but somehthing capable of dumping gallons on a target a hundred feet away in half a second. I just figured out how to build it but don't have the time because I re-enlisted in the marine corps and I'm shipping out at the end of the summer. I was initially thinking about experimenting with brass fittings and nozzels but the first few just didn't work. A few minutes ago I figured it out tho, the large irragation sprinklers they use to water football fields or in california the crops. They are fairly cheap and once you remove the rotation mechanism are designed to throw water a few hundred yards. And because they work on the same fittings as brass you can size it with a few pieces of brass to a threaded pvc adapter and mount it on the end of a barrel. You would have to unscrew the sprinkler head to fill the barell so each shot would take a while or you could add a seperate water valve to the barell for quicker refills.

Anyways I havn't seen any other ideas for this so I thought I would share it. A word of caution however. A barell full of water is probably the heaviest projectile your ever likely to fire and kicks like a mule. Now with dry projectiles the heavier they are they farther they go because that 100psi in your chamber has a chance to build up behind it. Inch and a half wide plastic bottles filled with pennies kick back hard and fly forever and water is even heavier because the whole barell is full. The thing here is that if there is a single weak spot in your design or build that spot is likely to fail. It probably won't be the chamber or barell more likely a coupling or bend. But when it does fail the whole air charge is going to expload out of there because water doesn't compress and you are basically firing a six foot long slug of water. In other words don't blame me if you lose a finger.

Harly


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 Post subject: Addendum
 Post Posted: Wed Jul 09, 2003 10:00 pm 
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Originaly posted by Harly,
The problem with most garden hose sprayers or brass nozzels is that most of them are designed to spray within ten or fifteen feet. So at the pressure a spud gun uses you will just create a fogbank right in front of your barell. Trust me I've tried it. You would really need an irrigation sprinkler head to get any range with such a large volume of water at high pressure.


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 Post subject: Good idea
 Post Posted: Thu Jul 10, 2003 9:00 pm 
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Originaly posted by Rocketbiker,
I've thought about this whole ubersoaker idea myself. I've got one issue with your design though. I don't think the barrel would be the ideal place for the water chamber. I think this scenario will end with the air pushing through the water and getting out before half of the water does. All of the water makes it out without the nozzel because the tip of the gun offers no restriction. If you use a 1.5" barrel and a nozzle that's less than an inch, once the water level drops some the air's just going to go around the water.
You need to have the water in a container with a siphon hose running in it to the bottom. This siphon hose should be able to be as big as you want. I wouldn't bother making it a lot bigger than the nozzle though.
PS I've tried the full barrel of water in a 1" barrel. I shot it from the hip straight up and the gun ended up on the ground. I can't imagine a 1.5" or 2" full of water.


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 Post subject: Addendum...easier way
 Post Posted: Thu Jul 10, 2003 9:00 pm 
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Originaly posted by Rocketbiker,
Had an idea as soon as I posted that one. Simple solution to your design. Just put a piston or fairly air tight slug in you barrel first to push the water.
This will prevent the air from getting past the water.
Just make sure your nozzle is on securely and that the slug won't damage anything on the back of you nozzle.


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 Post subject: Actaully
 Post Posted: Fri Jul 11, 2003 7:00 am 
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Originaly posted by Harly,
My last gun was a six foot chamber of 3 inch pipe and a six foot 1-1/2 barell. The problem I had with that gun was the chamber was too big you could fire the electric valve three or four times after you launched a charge and a get a strange tuba elephant call noise from extra air. And believe it or not the ten or twelve times I launched a full six foot barell of water with 100psi all the water left the barell. Of course I never fired it without the butt end on the ground but I dont see why you would need a siphon. The thing is whith a high enough psi the air wouldn't have a chance to get past the water and escape. Because the water is actually acting as a piston. Water is going to seek the path of least resistance a sprinkler head or the 100psi 3inch slug of air behind it. And Idealy you would be able to dial the air pressure to the point you could shoot bursts. A siphon tank just makes it heavier and more expensive to make.


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