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View Full Version : The Great Hydrgen Salute Can Cannon


mark
June 8th, 2001, 12:26 AM
Atlast, I've found something fun to do with hydrogen. Simply flling balloons and lighting them is pretty borring, so I have created this device. In short, its how you an make a tremendous bang with hydrogen.

materials:
2 empty 1 gallon paint cans
1/16" wide nail
Tomatoe sauce jar, bigger the better
1/16" wide electrical wire
Hydrogen gas chemicals

Procedure:
Take one of the paint cans and poke a hole through the bottom and top of the can with the nail. Youve now built the cannon.

Now to build the filling aperatus. Cut a foot of the wire and seperate the sheeth from the wire. Congratulations, you now have a very thin hose. Now, poke a hole through the metal lid of the tomatoe sauce jar. Put a 1/2" of the hose through the lid. Hot glue the hose in place to make an air tight seal. You have now built the filling aperatus.

Filling:
Thread the hose through one of the holes in the paint can. Cover the other hole with electrical tape. Now fill the jar up 1/4 of the way with water. Fill the other paintcan half way with water. Place jar in can. Add a tablespoon of lye to the jar and stir until dissolved. You should be wearing gloves and goggles for this. Rip a foot and a half long piece of alluminum foil in half and make 2 pellets. Drop in the pellets and screw the can onto the jar as quick as possible. Allow five minites to fill.

Firing:
Remove can from filling aperatus. Place can on top of 2 bricks. Make sure there is a space between the bricks and have the hole over this space. Remove tape from other hole. Light touch hole above the can. If all goes well, a lantern flame will be produced and will burn for several minites. As the flame is burning off the hydrogen on top, air will be mixing in through the bottom. When the hydrogen reaces its flash point in the can, the device goes off with a tremendous boom. With this device you can make defening noise for pennies.

Ill post more info later.

c0deblue
June 8th, 2001, 01:31 AM
This isn't intended as a put-down, but this device could be VERY dangerous. The explosive limits of Hydrogen are between 4% and 75% - the broadest range of almost any gas. Unless the paint can is COMPLETELY filled with Hydrogen (with ALL the air displaced), there's a better than even chance the gas mixture in the can will be within the explosive limit when lit, and could blow up immediately.

Exploding cans are unpredictable - in some cases they only rupture or pop their tops, but in other cases they produce razor sharp shrapnel.

"If all goes well" is pretty slim assurance that severe personal injury wouldn't result from lighting the tube on a device like this. Figure out a way to activate it from a safe distance and you might have a fun noisemaker. And use polyethylene milk containers or plastic bags - anything but metal.

Play safe!

[This message has been edited by c0deblue (edited June 08, 2001).]

mrloud
June 8th, 2001, 12:08 PM
This same experiment was demonstrated at a local university during an open day chemistry show. They did not use a paint can. Instead, the device containing the hydrogen was a cylinder made from copper. One end of the cylinder was sealed off with a lid that formed an apex. It looked a bit like some grain silos seen in the country side. At the point of the apex was a small hole. The other end of the cylinder was open.

The device was suspended with wires above the bench top with the cone pointing up. The hole in the top was plugged with Blu Tack. The cylinder was filled with hydrogen from a tank. The main hydrogen tank was removed from the proximity.

All of the above happened before the audience entered. During the show someone removed the Blu Tack and lit the flow of hydrogen escaping from the top of the cone. After a minute or so there was a huge BOOM that caused the 500 people in the auditorium to jump out of their skins. The copper cylinder hardly jumped at all.

They also demonstrated a small balloon containing oxygen and acetylene being ignited. It was much louder.

mark
June 10th, 2001, 05:13 PM
Ive had the can explode as soon as I lit it. It was very loud, but no harm was done. If you are concerned about shrapnell, then use a pringles can. It has a metal bottom,but the rest is cardboard.

Also, instad of using wire as the hose, use the hose inside of an aim n flame. Its much better.

mark
July 15th, 2001, 06:19 PM
Get out of my thread!

-Colza-
July 26th, 2001, 05:07 AM
We did a similar thing in 4th form science.

SafetyLast
August 5th, 2001, 12:48 AM
Mark, would vinyl aquarium tubing work instead of 1/16" wire sheath? the interior diameter is 1/8" is that too wide?
this is an extremely easy and cheap device to construct.
I like c0deblue's idea of activating it from a safe distance (i'll think of something, im determined to complicate this simple device)
I might even aquire some calcium carbide so that the can cannon ignites acetylene
(or would that be too powerfull and destroy it?)

mark
August 6th, 2001, 06:20 PM
Acetlyne works better, but takes longer to go off. As for hosing, it needs to be thin. The plastic hose from the inside of a aim nflame works perfectley.