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Re: pyrotech experts

Posted: Tue Oct 28, 2008 9:54 pm
by CapnTom
Hey Paddledog,
Have you ever used powdered carbide and water to form acetylene gas?
Not a sugestion to experiment with around children. But just curious. My father built a cannon
from the pages of Popular Mechanics out of PVC that used that as a charge. BIG BOOM!!!
He even scaled everything down to half-sized. Had a water chamber that you dropped
powder in through a small hole that also served as an ignition point. A lean mixture
would result in a really big bang; a rich mixture would give way to major flameage out
the muzzle.

Just curious.

Re: pyrotech experts

Posted: Wed Oct 29, 2008 5:11 am
by paddledog
Yup, Called a Carbide Cannon.
This is the one we grew up with:


[attachment=1]carbide cannon.gif[/attachment]
They can also be made from PVC,
[attachment=0]cannon1.jpg[/attachment]
There just isn't enough time before Halloween.
But when your ready, this is the guide to getting started:
http://www.amazon.com/Backyard-Ballisti ... 812&sr=1-1" onclick="window.open(this.href);return false;

Re: pyrotech experts

Posted: Wed Oct 29, 2008 5:32 am
by paddledog
Pam,
Sorry, conflicting social engagement, not gonna make it again this year.
I will PM you detailed instructions if you want.
Super simple

Re: pyrotech experts

Posted: Wed Oct 29, 2008 6:58 am
by canoe
Please do.

Re: pyrotech experts

Posted: Wed Oct 29, 2008 8:06 am
by DMG
You can break strips off of MRE heaters and drop them in 2-liter soda bottles with a few inches of water in them. Screw the cap on and you'll have a fairly loud pop in about ten seconds. Not sure where to get the MRE heaters. Maybe a military surplus shop or somewhere.

Re: pyrotech experts

Posted: Wed Oct 29, 2008 8:21 am
by DMG
Oh, and if a balloon filled with acetylene thrown into a campfire is heavenly, a balloon filled with a neutral mixture of acetylene and oxygen thrown into a campfire is devine. The one we set off in my high school shop class flattened my cloths against my body from ten feet away. Don't know if I'd recommend that for the kids.

Re: pyrotech experts

Posted: Wed Oct 29, 2008 1:23 pm
by paddledog
Actually the acetylene baggie is the easiest to regulate.
It's done by volume.
A balloon full is a lot of gas.