Old Carbide Cannon Project - Still Making Noise!

I get to blow off the cannon at several events during the year; especially around the 4th of July.  One of my favorites events is the Annual East Syracuse, NY Concert & Fireworks.  I set up near where they stage the emergency services vehicles and fire off around 40 blasts all afternoon and evening directly towards the concert goers before the big fireworks show.

My big old Carbide Cannon is a project I conceived of back in the 80's to answer the nagging question; "If you scale up a toy carbide cannon, will it produce a bigger boom?" I can demonstrate that the answer is a resounding yes!

Side view; the cone on the end of the barrel helps direct the sound and flames down range; it was salvaged from an old stadium speaker found in a junk yard.

• The Carbide dispenser is on top; each firing takes about a tablespoon of CaC2.
• The spark igniter is at the back; it's a simple spring loaded flint which gets scraped with an abrasive plunger which instantaneously detonates the acetylene gas.
• The cord with the "Monkey Fist" knot is decorative.
• I wear the sound attenuating headset (hanging over the barrel) every time; or I would be deaf...
• The pipe sticking down from the "T" is the 1 liter water reservoir, which breaks down the CaC2 (Carbide) into acetylene gas. The smaller red pipe sticking out the back provides leverage so it can be periodically unscrewed to change the water.

Tubes of pricey Bangsite, from the Canestoga Company (manufactured in China); and a cheaper Carbide made in the USA (works just as well, but a slightly coarser material)  

Stop watch and combination whistle/flashlight.  To get the loudest blast, very carefull timing is essential; the entire charging to firing cycle takes 50-55 seconds. The East Syracuse police require that I blow a loud whistle and shout; "Fire in the Hole" several seconds before every detonation - to give fair warning to passers-by.