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Posted: Tue Feb 12, 2008 8:04 pm
by bigbob12345
Get a ten foot barrel(otherwise your CB will be huge)and use it as a combustion it is not safe for pneumatic use if you want make a pneumatic make sure every part is nsf-pw otherwise you will be putting your life at risk.
There is no way that you can modify this for pneumatic use unless you want to die. Do you want to die.

Posted: Tue Feb 12, 2008 8:09 pm
by STHORNE
whats the big deal, its not going to blow if i take it to 30psi, i could do that with a foot pump.....


god, its not like i wanna launch cylinder blocks out of it, just golf balls and other sh!t.
There is no way that you can modify this for pneumatic use unless you want to die. Do you want to die.
is that a threat? lol

Posted: Tue Feb 12, 2008 8:11 pm
by thespeedycicada
ok but next time try and listen. You could put a gun made of pressure rated parts and put it inside this but there is no safe way to make it pneumatic.[/u]

Posted: Tue Feb 12, 2008 8:15 pm
by STHORNE
so do i have your permission to engage in this project if i dont go past 30psi sir? lol

but really , is it ok? i really dont wanna start over or make it a combustion :cry:

Posted: Tue Feb 12, 2008 8:16 pm
by bigbob12345
Takeing it to thirty psi is the equivalint in danger as taking nsf-pw to 200psi would you do that.
DWV is meant for no pressure situations it will normaly hold a decent amount of pressure it is just that the manufacterers dont make it with as high standards so the chance of a faulty joint is a lot higher.
I dont ude DWV in any thing not even combustions I just dont want to take the risk.
And a combustion will be more powerful than a pnuematic at 30psi so make it a combustion.
I would recomend to scrap it and use pw for it even if it is for combustion use but i guess it isnt that bad to use it for combustion.

Posted: Tue Feb 12, 2008 8:19 pm
by STHORNE
good point....unfortunately

im sorry for waistin your time guys, ill just throw it away and start over
(hell, mine as well buy a real bazooka and save myself some trouble) :cry:


ill see about making it a combustion, so if i do, what do u guys think about adding a propane direct injection system?





again, thanks for the life-saver guys :wink:

Posted: Tue Feb 12, 2008 8:20 pm
by thespeedycicada
No its not safe really its not.you could i guess but it would be a bad move.I have had dwv hold up to 80 psi but i was very lucky.im more worried about the pipe though i have never used dwv pipe just that one fitting.Fittings blow off but pipe explodes into shrapnel.

EDIT:Gah! you beat me.

Posted: Tue Feb 12, 2008 8:20 pm
by elitesniper
dont forget the fan :wink:

Posted: Tue Feb 12, 2008 8:23 pm
by STHORNE
i wont, i already got an old 5v pc fan from a garage sale lol


EDIT:
EDIT:Gah! you beat me.
ha ha, sure did :wink:

Posted: Tue Feb 12, 2008 8:26 pm
by Ragnarok
A handful of hints for finding good pipe and fittings:

If a Tee's side arm is curved or doesn't come out at a neat 90 degree angle, it's not rated. It also applies if the socket outer diameter is a different value to the rest of the fitting.
Those are the best rules I can give you on the subject, mostly it's just a case of learning it. There are some pictures somewhere comparing them.

Idea: Perhaps we should even create a mini quiz where people are shown pictures of fittings and text on pipes, and they have to guess. That would be helpful.

Sch 40 and pressure ratings are different things.
Now, in cases like this, an analogy to cars tends to help.

Say I'm a used car salesman, and I'm selling you a car. You want to know what it's horsepower is - actual figure, 213.
A rating would be like me saying: "I had it on a dyno last week, and it was measured at 215, give or take a couple."
Sch 40 is like me saying: "A specimen in this age range is expected to have 260."

If you wanted a vehicle with at least 240 horsepower, then you'd be sorely disappointed if you'd based your decision on the second statement.

It's the same here. With a rating, it's been tested and certified at that pressure - the car has been put on a dyno and checked.
With SCH 40, just a defining set of dimensions, it could hold the pressure, but you don't know - I've just gone to the internet and googled the car make - it's a russian roulette.

Posted: Tue Feb 12, 2008 8:30 pm
by STHORNE
kewl, thanks ragnarok

Posted: Wed Feb 13, 2008 11:30 am
by jimmy101
sthorne wrote: whats the safest way to modify this into a pneumatic?

i really dont wanna start over or make it a combustion cannon so plz just help me out
To make the gun safe as a pneumatic follow these steps;
  • 1. Tap a hose barb into the chamber somewhere.

    2. Connect a length of pressure hose to the barb.

    3. Put ammo in barrel

    4. Put the hose in your mouth and blow.
That is about the only way an experienced spudder would consider firing a gun made with Schedule 40 non-pressure rated fittings as a pneumatic.

Like others have said, the schedule has nothing to do with the pressure rating. The schedule mearly defines the diameters of the pipe and fitting. All schedule 40 components will fit each other. That doesn't mean they are pressure rated. Bottom line, a schedule 40 part may or may not be pressure rated.

Posted: Wed Feb 13, 2008 2:10 pm
by MaxuS the 2nd
Even if you were to make it pneumatic.. 30psi isn't exactly going to have a large punch now.

Posted: Wed Feb 13, 2008 4:03 pm
by TurboSuper
Can a sprinkler valve even actuate at 30 PSI?

Posted: Wed Feb 13, 2008 4:14 pm
by MaxuS the 2nd
It sure can, but will give a rather pathetic rush of air. Even if you did have a large chamber.