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Posted: Sat Dec 13, 2008 7:23 pm
by Moonbogg
Hotwired wrote:PVC isn't tempered glass... Last half a dozen pvc failures I've seen posted here consisted of fairly sizeable bits.

I wouldn't run out a generalisation on hearing of one incident. But it would be nice to see a deliberate cellular core ABS failure. Might require a hybrid mix or perhaps a pneumatic option.

Pneumatic would probably be easiest, cap a pipe off at both ends and pump til it blows.
Exactly, make a pneumatic pipe bomb. Thats an easy way. If I were to do it though, i'd make a closed off chamber and use propane to simulate a cannon with a clogged barrel or something.
I went to Home Depot today to get stuff for a new barrel, and there was a smashed piece of ABS pipe on the rack, totally smashed and had a nice crack down it. Stuff seems pretty gummy and tough.

Posted: Sun Dec 14, 2008 7:26 am
by psycix
Hotwired wrote: Pneumatic would probably be easiest, cap a pipe off at both ends and pump til it blows.
Downside:
The pressure is increased slowly and the pipe fails at its minimal maximum pressure. (minimal maximum?! oh well)
For example:
With a combustion or hybrid mix, the pressure goes up so fast, that by the time the pipe gets the chance to fail, the pressure may be WAY over its fail pressure, giving more "spectacular" results.

Another option is to charge a metal chamer to 300 - 500 psi and use a QEV to dump that into the ABS or PVC chamber. Blam! :D

This "creating of pressure spikes" is not just creating extra powerful explosions "for fun": realize that a barrel may experience the same shock loads of pressure.

Posted: Sun Dec 14, 2008 10:48 am
by Hotwired
Spectacular isn't required.

Besides. In a combustion the force doesn't last very long but if the chamber is pumped full of air at lets say 200psi and it then develops a crack I'd be surprised if you didn't get your catastrophic failure.

Shock loading it might give a different result.