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Posted: Wed Nov 22, 2006 5:53 pm
by jrrdw
I don't know the exact degree of the taper, but i'm under the impression that all fittings are tappered. Thats why they push out when you weld them together. Would sanding out the fitting change the tapper? If so, would it be enough to weaken the fit?

Posted: Wed Nov 22, 2006 6:06 pm
by sgort87
squeaks wrote:I disagree with gort.
That's not gonna be very good for your health. :P

"Certain" is still not good enough. You don't know it, but this really ruins the PVC. It warps, bends, and dmages in ways you haven't thought about and since it has been welded before, the chemical structure is changed and is weaker.

You can do this all you want, but please don't try to tell others it's acceptable.

Posted: Wed Nov 22, 2006 7:38 pm
by nicholai
squeaks wrote:I'm certain. Is that better. If it means anything, I'd stand right next to the pipe fitting when it was pressurised up to 150psi.
Im typically not one to "diss" another forum member for suggesting potentially helpful information but i think this is a stupid idea. The fact that you would disregard safety by standing next to a piece of overpressurized air chamber, made from material not intended for air pressure, does not prove that this is fool proof or that it even works. While it may work for you, what if a novice cannon builder did this and got seriously injured from the instructions you gave? Is your safety worth less than buying a new pvc fitting?

Posted: Wed Nov 22, 2006 8:08 pm
by Bluetooth
Do you have proof you are certain? I highly doubt you do.

Posted: Wed Nov 22, 2006 8:23 pm
by Hayseed_Andrew
As I read from another forum, When this blows out and kills all your future children, don't come running to us..... This is something I'd let the neibourhood idiot try first, then point and laugh when it blows a hole through his garage door.

Posted: Thu Nov 23, 2006 1:06 am
by squeaks
Ok, nobody beleive me, but I'll leave you with this last word. I have a cannon currently that got destroyed a couple times due to outstanding circumstances such as dropping it, etc, and now it has 3 fittings and two small sections of pipe saved this way. If one of these ever blows up on me I'll gladly tell and walk away in shame. Until then I'm telling you this is a cheap way that doesn't damage the pipe and is extremely usefull with expensive fittings and spots where you absolutely have to save the pipe or else scrap the gun. And to think I spent a whole five minutes making this post. LOL.
Thank you and you won't hear from me again on this one. :cry:

Posted: Thu Nov 23, 2006 2:11 am
by SpudStuff
The easiest way to save the fittings and keep them PERFECT is to use a Ram-Bit fitting saver drill bit. Yes, they are expensive but I have a 1.5", 2", and a 3". They work great and you can get free fittings!

Posted: Thu Nov 23, 2006 5:36 am
by rna_duelers
I have been guilty of doing this to many parts for my pneumatic cannons.But then again i have also died officialy before,so why not twice!I dont recomend anyone practicing this method.But over here in Aus the PVC parts are quite a lot more expensive and i cant aford to fork out $7 for a each new fitting everytime i want a new gun etc.And those parts are only in 50mm sizes so its adds up in the end.It's saftey Vs Cash for me.

Posted: Thu Nov 23, 2006 8:24 am
by experament_u2
i have being doing this since iv started building spudguns because like rna_duelers says here in australia the bits cost quite a bit and there is no point in throwing away good bits just with a bit of pipe stuck in them so if i can salvage any bits from my old guns i will 8)

Posted: Thu Nov 23, 2006 8:33 pm
by Infernal2
Well, there is a very good reason why this is an old plumber's trick. Its because it severely damages the pipe. Back before wide acceptance of state code regulations this trick was used to save money on job sites. If you are caught doing this in the US with a pressure or DWV application you might as well forget your license.

So what does that tell us? It tells us that those fittings are no longer usuable for pressure applications and may reach burst pressures at a much lower rating. Take it from someone with a license. This is a bad idea.

Posted: Sun Nov 26, 2006 9:01 pm
by Dom
squeaks wrote:I'm certain. Is that better. If it means anything, I'd stand right next to the pipe fitting when it was pressurised up to 150psi.
"As for the coffin sir, will that be in cherrywood or mahogany?"

Posted: Sun Nov 26, 2006 10:58 pm
by judgment_arms
Hahaha good one, I’ll have to remember that.

Useless post, yes, so sue me (read my disclaimer in “ghetto coke bottle” to find out what happens when you sue me.)