Where can I get a mauler valve?

[JuchTurtles]

@soakernerd: That's more battle-practicle than a normal SC, but still not great. You still have to push back the piston (unless I'm misunderstanding) and pump air into the back of the PC.

@martianshark: It's not that your materials are no good, it's you design. You could still use a fast opening valve, but it is the way your gun is designed. I believe I already explained why it wasn't safe. Btw, 80 psi is not low psi, PVC Sch. 40 only takes about 100 anyway. Were you planning like 150 psi? You will have an explosion on your hands. Low pressure for PVC is like 40 and below. Low pressure for ABS I think is even less (unless I'm mistaken).

So just clean up the design at least. Your materials should be okay otherwise.

[martianshark]

That's low pressure for PVC. The pipe I'm using is sch 40 and it's rated 340 psi.

So what should I do to clean up the design? I want to build this design because I have the right parts and it makes a huge blast.

[soakernerd]

@soakernerd: That's more battle-practicle than a normal SC, but still not great. You still have to push back the piston (unless I'm misunderstanding) and pump air into the back of the PC.

Since water doesn't compress, pumping water in pushes back the piston. If your piston seal is good, moving it back will also re-pressurize the gun.


Martianshark,
If I am understanding you correctly, This is basically a WBL, but you put water inside instead of a water balloon? From what I know of water, this will simply destroy the launcher, and injure you.

[JuchTurtles]

Since water doesn't compress, pumping water in pushes back the piston. If your piston seal is good, moving it back will also re-pressurize the gun.

I understand better now. That makes it way more practical because there is no repumping with air, just water. That makes it like a Seperate PC gun yet it has power like a SC. Cool. This would be a good design for martianshark to change to.

Martianshark,
If I am understanding you correctly, This is basically a WBL, but you put water inside instead of a water balloon? From what I know of water, this will simply destroy the launcher, and injure you.

Exactly what all of us have been saying. martianshark, your design doesn't work. I know you really are intent to use this design, but it just doesn't work.

That's low pressure for PVC. The pipe I'm using is sch 40 and it's rated 340 psi.

Last time I checked, PVC was only rated for 100 psi. I guess I was just mis-informed. But 80 psi is still huge for water guns. The average APH runs at about 40.

So what should I do to clean up the design? I want to build this design because I have the right parts and it makes a huge blast.

You can still make it powerful, just make a Supercannon, either Ben's way or soakernerd's way, which is similar to adronl's way.

You could even make an APH.

[martianshark]

*sigh* I really wanted to make my own air-powered water cannon, especially because I have a lot of 1-1/4" PVC pipe to get rid of. Oh well. What can I use for a piston that fits into 1/4" pipe - or is there a way to fix this design?

[JuchTurtles]

1/4" PVC pipe?!?! That's tiny! You'll need at least 1 1/2" pipe to make a good piston gun because, 3 feet of 1/4" pipe would hardly hold any water. 3 feet of 1" pipe wouldn't even hold that much water. I suggest using 2" or more PVC pipe if you are making a SuperCannon.

If you want to get rid of tiny pipe, just make an APH with smaller pipe and make it go on riot blast. If you make it with several PCs (using the 1"), you should be fine with high output and range.

That's what I think you should do. It's not worth it to use 1/4" pipe on Supercannons, or even most homemade guns. Just make an APH.

[soakernerd]

I believe he means 1 1/4" pipe. I am using that to make the piston for my 2" supercannon, along with the O-rings from a Waterzooka.
Their O-rings are designed to fit perfectly between 1 1/4 and 2" pipe.

[martianshark]

I said 1-1/4" PVC pipe, not 1/4"! I didn't even know pipe that small existed. Where can I buy small pipe like that anyway? Also, I'd rather not build an APH - they're too expensive to make. I like to build guns that are cheap and make my own designs.

@soakernerd: I need a piston that can be bought at a hardware store or something.

edit: About my other idea, why doesn't a WBL cause a pressure spike? And could some sort of fast-acting pressure release valve solve the problem?

[JuchTurtles]

Sorry for my misunderstanding. I thought you were saying 1 to 1/4" pipe to get rid of, but I misread. I think they do make pipe that small, but it's rare and hard to find. I've seen adapters and stuff for it though.

Anyway, I don't know about the pistons but the reason a WBL doesn't cause a pressure spike is because a water balloon is a solid, and it gets fired out straight. Water, or any liquid, get pushed out and goes outward as well as forward.

[martianshark]

Oh. I think I misunderstood what a pressure spike is. I thought it was a sudden change in pressure with something in its way. If I put a check valve or something on the top, would that stop it from possibly exploding? If not, I have a new air powered water cannon idea:



See, the air pushes the water balloon or some other kind of "water shell" until it hits the screen and the water flies out. I don't know if it'll work, but if it doesn't, I can just take the screen off and I'll have a WBL/SBL.

[JuchTurtles]

That would be pretty cool, but it would be just as hard to reload as a WBL. Not very practical but that would do some soaking.

It probably would have like 10 feet of range and it would just be a riot blast. I don't know if it's that worth it.

[soakernerd]

That looks really cool. As a way to speed up reloading, why don't you just not glue the barrel to the valve? That would allow you to take off the barrel and reload.

Also, what is a "SBL"?

[martianshark]

@ soakernerd: That's what I was going to do. I usually don't glue things that I don't have to.

[SSCBen]

martianshark, if you want to save some money, make a small Supercannon type water gun or adapt the APH to be cheaper. You can make a water gun with an angled chamber like the APH so you don't have to use pistons and can save some money. The water gun could be easily filled by opening the valve and pouring water directly in and a schrader valve on top of the pressure chamber could pressurize it.

Also, the pipe might have a rating of 340 psi, but that doesn't mean you can pressurize the system to that as the other components might have lower ratings. Anyhow, that's water pressure, not gas pressure. Water stores nearly no energy as it is essentially incompressible in the liquid state. Pipe manufacturers give no pressure rating for gas because they don't want people using it with pressurized gas.

You might find this page helpful: http://www.spudfiles.com/spud_wiki/inde ... _Rated_PVC

There's nearly no reason to run pressures higher than 120 psi or so with PVC. I don't ever exceed 100 psi with PVC period, and generally operate at about 60 psi when I want a "high" pressure.

I'm not sure why shooting water from a barrel is particularly dangerous. All I know is that it has caused potentially serious problems in the past.

[JuchTurtles]

Really in water guns there is no reason to go over 80 psi, or even 60 psi. Unless you are trying to make a performance blaster/cannon, I wouldn't. If you have to have higher pressures (which means that it can't be used in wars) use Sch. 80 PVC. That can safely operate at about 200 psi I believe. If you make something with high pressures, don't use it in wars, because there are some bad things and injuries that can happen, especially if put in the wrong hands.

Now cannon wise, the WBL cannon that you shoot a WB through a screen would only be good for short range combat like scrmishes. After further thought, I believe that it will only get about 20 feet of range, even though it brings a huge explosion type blast. On a side note, Make sure the screen is set and placed well. You do not want to shoot someone with a 60 psi WB and screen at point blank or even 10 feet. Also, I want to mention that the screen has to have some sharper edges to burst the rubber. Otherwise, it should work, it's just that I don't think it's that worth it to use in hardcore combat. Maybe you don't want it to go into big time wars.