SpudFiles

( PNEUMATIC )

For making a water balloon gun, what size barrell would I need, and what is a good PSI to shoot. Also, does it make for good ammo ( it being made of water and such )?

It won't work as ammo. Friction and pressure will tear the balloon apart before it leaves the barrel.

What size barrel? Well that really depends on the size of the balloon/how much water you pump into it...

I really wish someone would come up with a good solution that would allow people to launch water balloons. My idea is to get a foam sabot that is larger than your water balloon, and drill a large circular hole (the same size as your balloon) in the center. This would protect the balloon from friction, and the foam would simply slow down after 10 feet, allowing you to use it again.

May not work though... I have not personally tried it

i reccomend a 3" wide barrell and foam sabots

so something like this would work?



red = stopper (to keep holder inside barrel) | green = water balloon | blue = holder (pringles can, etc.)

The balloon could just pop due to the force of acceleration.

And benstern really likes to mouth off when he knows nothing.
Doesn't even add any disclaimers like "most likely" or "I suspect"...

Has no excuse for it either, considering we have a thread <b>3 pages</b> (IIRC) long on the matter on this forum, and at least one person has built a launcher specificaly for water balloons.

Water balloons can survive launch, but it takes a bit of effort to protect them from the pipe wall; as benstern said, things get ugly when the rubber meets the pipe..
We have a thread about this in the ammo section, why don't you check it out?

As to barrel diameter;
I typicaly launch (roughly) 50ml waterballons from a 2" barrel.
Extrapolating, a 2.5" barrel could shoot roughly 100ml ballons.
A 3" barrel could shoot roughly 160ml balloons, which is getting a tad big.

...and "captive sabot" designs are generaly a bad idea, with your specific idea being the worst of the breed.
Someone over at spudtech built a captive sabot design and used it to launch water balloons. Why don't you head on over there and search for it?

just dont fill the waterbombs up to much and shoot them like that, me and my freind use to shoot paint filled water bombs up and shoot them at his dads shed to paint it worked fine and got $50 to do it aswell. take the water bomb down to your local plumbing store blow it up with air to your desired size ours were about <-------------------> that big, and stick it in the pipe until you find the size needed. why does everyone on this forum get technicle about things? some of the simplest ideas work the best. edit: woo im a specialist now

yer it does work. but dont use it in a waterbaloon fight...i dont have to explain why

have you tried lubing up the barrel to reduce friction.

Don't overcomplicate things with sabots due to people posting incorrect information. I have a 1 inch barrel pneumatic gun from which I often shoot water bombs. It will only work if you pour a fair bit of water down your barrel first and shake it all around with your hand over the end to lubricate the entire barrel. Dump out the water, fill a water bomb up to a little over the thickness of your barrel (I would suggest not much over a 2 inch barrel, since the bomb will be weaker as it gets larger). Run the bomb under the tap to lubricate it, then hold it over the end of your barrel and allow the water to spray out of it until it's a tight fit. Tie the end and load it down with a broom. That's what I do and have only had a couple of failed shots (Bursting within the barrel)

I have never shot one above around 70-80Psi. I think they would probably burst at pressures much higher than that if they were a very tight fit - you would want some clearance between the balloon and the barrel diameter at really high pressures (In my mind, never pumped my gun up super high anyway)

They're quite fun to shoot. I've only ever shot water bombs up into the air because I don't have to worry about what they're going to hit as opposed to say, marbles. They are quite odd though. Shooting straight up, they have a pretty linear trajectory. However when I first built my gun I shot them horizontally. After about 20 metres, they would start to go way off course, darting in a random direction to a really significant extent.

Interesting.

Line the inside of the barrel with paper, fill the balloon with water while its inside the barrel and there we go.

No rubber-pipe contact and the balloon will keep the paper attached to it until its out of the barrel.


Something stronger might be water filled condoms and a lubricated barrel even if that does sound a bit dodgy

And then of course you take a 3' wide barrel and shoot a bowling ball using a 1968 chevy corvette as wadding... Nah dont get to complicated, I agree with Deactivated 1, And hotwired, Get over your PVC fetish, PLEASE!

It definately works. People build launchers with the specific purpose of launching balloons.

Using too much pressure will however shred the balloon. They are quite fragile projectiles.

A correction to Chubsters drawing. You would need a release of some sort for the air and/or exhaust, so that once the captive sabot had reached the end of the barrel it wouldn't have to deal with the pressure. Also, I have never tried shooting balloons, but I would think that adding some air in with the water could help cushion the balloon during launch.