Hi everyone, new guy with cannon pics

[beergut]

Hi guys!
So, I've been reading the forum and I'm real impressed with some of these cannons! I'm 33 and I've built maybe 3 or 4 cannons in the past 15 years.

I started building my "Patriot" cannon about a week ago. So far I have about $170 into it. It should be finished in about a week with a sweet paint job.

It's a combustible hybrid, propane & compressed air. It's built with #40 PVC. The barrel is about 5' long, 2.5" o.d. The ignition I pulled out of an old gas oven. It's pretty sweet because it gives me 4 huge sparks, which allowed me to build a nice spark rail that will span the entire length of the combustion chamber... no duds here! The only draw back is I need to plug it in, but I can live with that if it means 4 nasty sparks to excite the fuel mixture.
The blower will sit on top with a ball valve keeping it cozy being the fireball. The air tank still needs to be built and attached... I know it's not the nicest cannon on here but when she's all painted up and mounted in her base... My wife will have competition! Colors will be red, white & blue.

I'll post more pics and a clip shortly... if anyone is interested.

Thanks, Mike 8)

[Bluetooth]

WOW !! I wish I could build a cannon that nice . That looks very clean and powerful.

[Pete Zaria]

I know you mean well, man, but DO NOT FIRE THAT GUN AS A HYBRID. Propane alone is OK, but firing a hybrid mixture in that chamber could result in death. Literally.

You have DWV parts (Drain, Waste, Vent) on your chamber. These parts are NOT pressure rated, and ARE NOT SAFE for pressures over 100psi MAX.

EVERY single part on your chamber should say NSF-PW to be pressure rated. Your reducers and that Wye are definitely not NSF-PW and I'm not sure about several other parts.

You should build a hybrid out of SCH80 (or #80 as you put it) PVC, with NSF-PW parts. Some people use SCH40 NSF-PW but I personally think that's dumb for anything over a 2x mixture.

Nice design... You can re-use the ignition system and propane meter system in a properly built gun, but you really should not use that chamber for hybrid mixtures. It's suicide.

Sorry to rain on your parade, but nobody likes dead forum members.

Peace,
Pete Zaria.

[beergut]

Hey, thanks for the input. All of the pipe I used is SCH40 NSF-PW. I have some of the other stuff in the basement, it's real light, and it's easy to tell the difference between the two, the pipe I used is heavy. I'll consider what you said about not making it a hybrid, I don't want to take any chances and it's easy enough the get SCH80 and do it right. This will still be a real fun propane gun though.



EDIT-
I just grabbed a piece of the pipe I used... It's stamped "ASTM D-1785
NSF-pw 280 psi @ 73* F NSF-dwv"

So I think I'm good...right?

[Insomniac]

The pipe is not the only thing we are worried about. Some of your fittings are DWV, and are not designed to hold ANY pressure. Even though they are not pressure rated, they should be fine for a REGULAR combustion. If you fire it as a hybrid, most likely they will shatter. You can tell from the short socket depth that they arn't pressure rated.

The only pressure rated part I can see is the endcap on the propane holder (well I THINK it's pressure rated)

[medievalman]

well, i wouldnt use that gun as a hybrid if i were you. it has been tested to 280 psi, but hybrids often get in the 200-400 psi range or even higher. it would definetly be very dangerous, and keep in mind it is tested at optimum conditions. so as i hybrid, i would say no, but as a propane injection, i would think that would be fine. remember, PVC doesnt show up on x rays

[Torch]

Pipe is fine, some couplings are not, like Pete said. If you use a hybrid fuel mix it WILL EXPLODE as DWV can NOT stand the pressure, I used DWV parts in my air cannon and I have to trash most of it. Better to be safe then sorry


Edit: Haha, got beat to it..

[beergut]

Ohhh.
I've been using this pipe and these fittings for about 15 years on all my previous cannons and never had any problems.

You said "some" of the fittings were not pressure rated. Do you know which ones?
I might just disassemble it and find the pressure fittings and do it right.
Home Depot has all the fittings in one location, why would they sell no pressure fittings to use with pressure pipe?

I'm not looking forward to taking my gun apart... but it sure beats having my cannon rip me apart....

Do you suppose it'll be ok to use it "as is" with propane, and I'll just build another with SCH80 later on.


EDIT-
oh, Questions answered... I type way too slow!

[medievalman]

yes, it should be fine to use "as is" with propane, these pressuses rarely exceed 70-90 psi wich still gives you a good safety margin. i hope you have fun with it!

[experament-u2]

that is a awsome gun the design is trippy good job

[zeigs spud]

very nice work but agreeing with the other guys i'm really scared of u firing that. nice work u show experince but mabey make a new one?

[beergut]

ya, I'll keep this one as a propane only... Then I'll begin building a hybrid soon... I'll call it "Patriot II Sr"

Thanks for the lesson, who knows... maybe thanks for saving my life.....

[skinner]

that looks great, i really like the spark strip, the whole setup is good

[sjog]

Beergut Hey is that your boat! Nice pic. I have a boat too.

[MrCrowley]

Just remember reducers arn't pressure rated, you have to use bushings instead.

but nice gun anyway