My P.R.H.

[adronl]

Let us know when it the bottle breaks which is pretty much inevitable. What pressure are you running? I think those bottles explode just over 90psi give or take if it is a 2liter. 3 liter's can hold more it makes me remember an episode of Mythbusters. Good luck and I hope you don't get hurt. Also you can pre-pressurize with just a water hose if that is a 3/4" threaded ball valve you should get 60-80psi which is pretty safe for a coke bottle. Last supposedly Pepsi bottles hold more pressure but that may be some BS. The last link is the best actual scientific testing and results from real scientists

http://wiki.answers.com/Q/How_much_psi_ ... ottle_hold

http://www.instructables.com/answers/ho ... le2l_hold/

http://kwc.org/mythbusters/2005/11/epis ... tatio.html

[cantab]

In my experience pop bottle thicknesses do vary. Supermarket own brands tend to come in thinner bottles than coca-cola and pepsi.

[C-A_99]

http://www.sscentral.org/homemade/air_canisters.html

In this test, a 2L stands over 140 PSI. At typical homemade operations, you shouldn't and probably will never get more than 80 PSI in there. Of course, PVC would be pretty much guaranteed safe, given everything is pressure rated. Most human operated pumps (particuarly bike pumps and water pumps made for water guns) probably can't put more than 80-100 PSI, depending on the situation.

[cantab]

I think the main risk is failure if the gun is dropped or hit. Some years ago I made a crude vinegar and bicarb bomb. Set it off by chucking it at the ground hard, made quite a loud bang.

[Silence]

cantab, I used to be worried about impact even with PVC. Ben linked to some nice videos of impact tests at high pressure, though, and the PVC canister never shattered until it was chilled. I'd still be worried about PVC degrading under UV light from the sun, though.

[martianshark]

I have some shot pics of it now:





Also, it hasn't broken yet.

[Silence]

Nice. What are you using for the nozzle?

[martianshark]

I already explained that to you. I used a male hose adapter to connect it to a sweep nozzle that was meant for a garden hose.

[JuchTurtles]

What's the range, it looks like a powerful shot. It's nice it hasn't broken yet. Cool!

[martianshark]

It's about 50 ft. By the way, I went to the store yesterday and got a pulsating sprinkler. I used it for my water gun:





The shot is really cool now, and it has really good range, but as you can see, the metal spike is dangerous. Is there something I can do to make it safer?

[cantab]

That sprinkler is unusual. What does it actually shoot like?

As for the spike - saw it off and cover the cut end with duct tape. Alternatively, if you would like a forward handle, drill a hole in the spike near the top, and a matching hole in a length of pipe. Slip the pipe over the spike, and use a bolt through the holes to hold it.

[Drenchenator]

I've never seen a sprinkler being used like this. Is it accurate? Can you it a target from a distance. Also, is it heavy on that side. I think a pulsing shoot is useful, but I never would've thought of using a sprinkler.

[JuchTurtles]

This is interesting. I would do one of two things for the spike.
1. Partially saw it off and use as a handle.
2. Try to make it longer and use it to your advantage (use it as a steadier or bipod).

Doesn't the head turn? Does it fire funny? I don't understand how it would work that well. At some point (possibly when the bottle breaks), you might want to replace reservoir with a pipe of some sort. Btw, good job!

[martianshark]

I've never seen a sprinkler being used like this. Is it accurate? Can you it a target from a distance. Also, is it heavy on that side. I think a pulsing shoot is useful, but I never would've thought of using a sprinkler.

I could probably hit a target from a distance. It shoots really far, and it isn't entirely accurate, but it still shoots really well. And it's not heavy. It's a light sprinkler.

[martianshark]

This is interesting. I would do one of two things for the spike.
1. Partially saw it off and use as a handle.
2. Try to make it longer and use it to your advantage (use it as a steadier or bipod).

Doesn't the head turn? Does it fire funny? I don't understand how it would work that well. At some point (possibly when the bottle breaks), you might want to replace reservoir with a pipe of some sort. Btw, good job!

That's a pretty good idea. Yes, the head turns, but you can control it's pattern to a minimum of 20 degrees, which isn't very badly inaccurate. And I used a bottle for 2 reasons:
1. It's way cheaper, and they don't sell large pipe in small sizes.
2. It's clear, so I can see how much I've filled it.

Edit: Oops, I double posted!

Edit: I tested my water gun's range with the pulsating sprinkler. It's 41 ft. It's not as far as it was with the sweep nozzle, but it's stream is more thick and it looks like it has more shot time.