SpudFiles

All that is needed is pretty much what you sated earlier. For performance purposes, you could (if your cannon allows the room) tap the blowgun directly into the top of the valve with just a close nipple. This will eliminate the hose, decreasing pilot volume, and increasing performance.

As far as costs, modding does cost more to start with but will save money in the long run (not needing to buy batteries and such).

spudy buddy wrote:elitesniper: i thought moding it pneumaticaly cost more then electric Gues i was wrong.

No, that's quite right. Modded: Blowgun, couple of hose nipples, bit of hose and some epoxy - a few bucks. One off cost.
Electric: Three 9V batteries, three battery clips, a switch, and a box to put it all in - quite a bit to start, and you have to replace those batteries regularly.

you know it took me a while to build up the courage to mod a sprinkler valve but honestly once i did it the first time it is so easy

THX guys. I have anouther Is puting some sort of blast cover/sheld around the chamber a good idea incase the pipe fails? Probably something like one of the legs from an old pair of jeans. I also hear to keep PVC away from light and this would help since it's very sunny here in Idaho during summer.

Does anyone know what diameter blowguns are?

BTW is there any way to mod a valve in a way that doesn't require drilling holes?( not that I can't, I would just prefer not to)

Well as long as you use all pressure rated parts for the gun, you won't need cover/sheild around the chamber unless you wanted to because you can never be too safe i guess.
Also safe working pressures would typically be around 100-120 psi.

spudy buddy wrote:Is puting some sort of blast cover/sheld around the chamber a good idea incase the pipe fails? Probably something like one of the legs from an old pair of jeans.

Shields around the chamber is generally considered useless by most experienced spudders. Jeans fabric especially will do nothing to stop sharp PVC shards. If it could, then we'd all be wearing (fashionable) denim stab vests.

Ok THX. I wasn't planing on putting one on unless the more experienced people thought it nesisary anyway. I read somewhere else about the denim but I too thought it would do nothing against PVC.

Plus i don't have a compresos so I would probably only get like 20 psi or watever is posible with a bike pump. Anybody know

Also I would like my gun to be a sniper with 1/2 inch pipe because I have a lot and some fittings from when i made a blowgen with a soda bottle taped to one end. That thing was powerful( for me not for you guys) but I want something more. How big of a chamber do you guys think I need made from 2 inch pipe, and are there 1/2 solenoid valves because I haven't found any?

Try to shoot for a 1:1 ratio (see chamber to barrel ratio in search / wiki). This seems to be a good start for a pneumatic.

As far as 1/2" solenoids, I've never seen them that small, but a 3/4" can be reduced.

THX once again. A 1:1 was what I was thinking to do. one more question. Is a modded solenoid valve the best valve for me or would something elc work/ be easier to make/cheper for me like a piston valve?

Well, that would depend. Assuming this is your first, I would suggest the modded sprinkler. It will be easier to use.

Now a piston valve does give better performance, but if you've never seen a modded sprinkler valve in action, I'm pretty sure you're going to be impressed with it.

Thank you. It is my first.

Question about cementing: In real welding if the welded parts fail it is almost never on the actual weld. The weld is almost always stronger then the base metal unless it is a defective weld. Technically when gluing PVC it welds the two parts togther into one. So my question is this: Is the cannon more likely to fail at the pipe or at the weld?

If it is properly welded, and the right amount of pressure is used, it is not likely to fail at either.

In my experience however (with controlled failings) it seems to favor the pipe more than at the fitting. This may be due to the double-thickness created by the fitting and the pipe.

Ok I thought so.

Would i need a ball valve and a schrader valve like some people have or what? Is that to stop the schrader valve from leaking at high pressures how high do you think i can get with a foot pump?

If you're talking about a ball valve before the sprinkler valve, again, that depends. The reason for this valve is because some hand pumps will not allow the sprinkler valve to seat while pressurizing the chamber. One will generally close the ball valve, pressurize the chamber, then open the valve. This will allow the chamber air to seat the sprinkler valve. It may or may not be necessary for you.

As far as the schrader goes, that depends on your pump. Assuming that "oot pump" is a typo, and you meant foot pump, then you probably will need the schrader. I recommend the screw in type schraders, and they can generally be found in a hardware store near the compressors. They cost a little more than the pop in type but are worth it in my opinion. One can also be purchase online at BC Arms.

Ya sry "oot pump" is a typo but i fixed it now. But what i ment was having a schrader screwed into a ball valve and the ball valve hooked up to the chamber. they keep the ball valve open wile pressurising and closed it before firing.