Hybrid Question

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
potatoboy00
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Wed May 23, 2007 7:42 pm

ok im making my first hybrid i know all of the ratio's and everything i just want to know can sch 40 hold a 2x mix because i live out in the boon docks and nowhere around me sell sch 80 is there any way i can strengthen the sch 40 if it will not hold a 2x mix let me know guys -Z
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Velocity
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Wed May 23, 2007 7:48 pm

I'm no hybrid master, but I think that SCH 40 would probably be able to handle a 2x mix. It certainly isn't ideal, and it certainly isn't the safest thing, but it probably would not exploded immediately. If you were to do this, make sure all of the fittings were NSF-pw or NSF-61 and insure that the pipe had an actual pressure rating. If your supplier does not provide PVC parts that meet the above requirements, you should not build a hybrid. Also, keep the hybrid small (2" and under), because those parts have a higher pressure rating than the bigger ones. Finally, I would set up some type of remote ignition system, in case it does blow.
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mark.f
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Wed May 23, 2007 8:49 pm

You cannot order a 5' length of 2" SCH-80 from somewhere for chamber and barrel sleeve? That would definitely be THE BEST thing to do.

But, if you can't avoid it, 2" chamber of SCH-40 pressure rated pipe and fittings would probably hold. I'd definitely work on a remote ignition. Simply a string pulling on a BBQ igniter will work if you're far enough away.
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Pete Zaria
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Wed May 23, 2007 8:55 pm

Assuming every part on the chamber is NSF-PW (not just sch40) it will be fine as far as I know. I've seen guys take sch40 nsf-pw to 3x, but thats probably a bad idea. It should be fine for 2x though.

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hi
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Wed May 23, 2007 9:24 pm

it will hold it, but it isnt safe and it not recomended. i think that DR used sch40 on his first hybrid, but it still isnt smart.
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Thu May 24, 2007 10:02 am

GasEq says 2x Propane/air will give 260 PSIG. Of course, in a real gun the spud moves (or the burst disk breaks) well before max pressure is reached. But, there is always the possibility that the round jams or you used to thick of a burst disk.

So, a 2x hybrid in sch40 pipe is probably not a good idea. Just to close to the pressure rating of the pipe. It might work OK 100 times then fail on the 101st.
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Thu May 24, 2007 10:07 am

But at the same token, PVC is in no way intended for use in construction of cannons, of any sort. So I think we all take that risk that on the 101st charge it will fail and shower us with hot, sharp plastic shards.
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Thu May 24, 2007 12:13 pm

There is a big difference between running a 260 PSIG rated piece of pipe at 60 PSIG peaks (generic combustion gun peak pressure) and running the same piece of pipe routinely at 100~200 PSIG with an occasional excursion to 260 PSIG.

So no, not "at the same token", big ass difference!
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Thu May 24, 2007 1:52 pm

Nah not really.
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jimmy101
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Fri May 25, 2007 11:06 am

ShowNoMercy: I can't tell if you are an idiot or just being an asshole.

Currently, I leaning towards and "idiot asshole".
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mark.f
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Fri May 25, 2007 11:23 am

Gaaaagh! Let's not get into an argument. Potatoboy00 has heard enough to make his own decision. Let's just hope he uses his head and doesn't do anything unwarranted.

ShowNoMercy, your "Nah not really." response was kind of pointless, though. If you're going to argue with somebody else, at least use more than three words. :P But, really, argue over PM, not in this thread.
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