SpudFiles

Would it be safe for use in a metered propane combustion or would it be better to just get the ABS cell core? I'm asking because getting a Pressure rated 4" is a pain the ass right now.

I'd say get solid-core anything. After you've got solid core, it really doesn't matter if it's ABS or PVC, (well, to me at least). Just don't use that cellular core. Use solid core ABS or PVC.

BTW, you can't get pressure rated 4" PVC? Nearly all the home depots I see nowadays have a little rack on the pipe aisle with 1' lengths of 4", 3", and 2" SCH-40, for "scrap". The 4" length would make a good chamber. If you needed longer than 12", just use a coupling.

My lowes only goes up to 2" in solid wall:(

Now you've done it . . . . you started the solid core / cell core debate. Solid core PVC is significantly more expensive but pressure rated. NECESSARY for pneumatics. I have personally ONLY used cell core PVC chambers in my guns and have never had a chamber failure, I had one of my solid core barrels blow up on a friend of mine though. Combustion guns using conventional fuels loaded with a potato will only generate about 40psi max on detonation. The spud is coming loose WAY before that chamber will explode. Propane has a pretty high pressure spike so I would keep the pipe lenght short, like 12" with a coupler on the cleanout end. Also, don't put the big tapped hole for the propane meter through the middle of the chamber, this will be the weakest place, put it through the coupler where t's double thick. I think you'll be ok but I would start with some low power shots till you're sure. Even Easy-E wore saftey glasses!

Haha, nice post, but I know all of that.
I'm 1337 in potato guns, but I have no experience with cell core PVC and lots of experience with Cell core ABS.

Haha, Easy-E, safety glasses, I dont think so since he never use any other kind of protection;)

Do you have a Home Depot? Is all you checked at Lowes? Like I said, Home Depot has the pretty little rack with 1' lengths of 4" pressure rated SCH-40 on it.

You've obviously been in this for a bit, so I'll be uncharacteristically short. Yeah, I think cell core pvc ,for pretty much any conventional cobustion gun would be ok.

ya until some crazy phenomena happens and you are pelted with thousands of razor sharp plastic shards lol.

Actually TaTer, I've had a solid core barrel blow up . . . it didn't blow up into thousands of tiny shards it blew up into 9 or 10 3 to 6 inch shards and albeit relatively sharp barely going fast enough to do any damage. It was my gun but my buddy was using it and all he got a a small cut on his forearm . . . no big deal. (he still thought it was cool) The thing to remember is that combustion guns are low pressure, 30 to 40 pounds max. 15-18 guns and 5 years and I've only used cell-core PVC for my combustion chambers . . . It's FINE.

my bad i got confused... for some reason i thought you were talking about abs lol. abs will blow up in to thousands of shards pvc wont... i just realized i stupid i was to post that . i must not have been thinking straight at the time. oh well. oh and i like you photoshopped avatar its........................interesting

Actually King_TaTer you had it right the first time, PVC turn into shards and ABS kind of splits down the side.



Cannon Freak.

No, Tater, you were right, PVC shatters into tiny shards, but there has to be extreme pressure behind it. I saw a vid a couple years ago where this guy buils a PVC pressure vessle just for the sake of demonstrating exploding PVC. If memory serves he had over 200lbs of pressure in it and he had to shoot it with a .22 after damaging it with an axe. When he shot it, it exploded into lots of sharp shrapnel, but it was mainly the doing of the pressure. I have a buddy of mine who is a plumber and he will only build ABS guns. He says that when ABS fails it doesn't shatter like PVC but it stretches and and blows out like a plastig baggie. (do a ziplock baggie and squeeze it slowly so a side blows out) ABS also has chemical resistance that PVC doesn't. He's an ABS guy and I'm a PVC guy. Bottom line is that we both build basic combustion guns, neither build enough pressure to break cell core PVC or ABS. And that's not a photoshopped avatar dude, thats really me. Ain't I a handsome devil?