Oxy-Acetylene.

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Postby blackspire » Wed Oct 18, 2006 8:04 pm

So I am building a new, metal potato gun. It has a 4 inch, by 2 foot long chamber, with a 2 inch by 4 foot long barrel. The chamber wall thickness is 1/4 inch, while the barrel wall thickness is 1/8 inch. It is all going to be welded together solidly. I have an endcap similar to what you would use on an ABS gun, just a little bit different. And, as the title sugests I am going to be using oxy-acetylene. My only real worry, is that on here I saw a thread where a guy had made a metal potato gun, and when he put the oxy-acetylene into the gun, he screwed the endcap on and someone pointed out that may be a bad idea due to any static electricity that may be created. If anyone can point out a major design flaw, let me know. I already have all the metal, so I can't just "not make it". I would like to be as safe as reasonably possible with this gun, as I know that oxy-acetylene can be dangerous. Any input is greatly appreciated.

-Matt
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Postby Drew Rowland » Wed Oct 18, 2006 8:17 pm

The major design flaw is that your using oxy-acetylene.
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Postby SpudStuff » Wed Oct 18, 2006 8:18 pm

Use teflon tape to secure the end cap. The oxy-Actylene should be okay but only with good welds.
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Postby Freefall » Wed Oct 18, 2006 9:06 pm

Unless your welding is pressure-vessel certified, I wouldn't recommend using oxy-acetylene.

If you're concerned about sparks, use a bonding strap between the chamber and cap.
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Postby SpudStuff » Wed Oct 18, 2006 9:44 pm

Test the chamber with water or oil to high pressure first.
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Postby Navigator7 » Wed Oct 18, 2006 10:56 pm

How are you going to add the two gases?

Also make sure the acetylene tank is vertical for at least 24 hours and never lay it down while in use.
Otherwise you might enjoy an Oxy/acet/acetone cannon which "if" ignited could send a tremendous sloppy flame out the barrel.
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Postby blackspire » Thu Oct 19, 2006 9:43 am

I'm going to add the gasses probably through a normal torch you would use for welding.
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Postby pbmann123 » Thu Oct 19, 2006 7:10 pm

Not if you value your fingers.


Edit: Shift key malfunction
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Postby Navigator7 » Thu Oct 19, 2006 11:57 pm

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by blackspire
[br]I'm going to add the gasses probably through a normal torch you would use for welding.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I'm not a combustion cannon fan for a few reasons...and don't have a lot of combustion experience...but I do have a lot of shipyard experience with oxy/acetylene.

There is no doubt you will get a bang out of this.
The use of an oxidizer in a steel pipe is the problem in my mind.
It's human nature to push the envelope.
If you use more and more propane in a spud gun, it won't work.
Not true when O2 is present.
You might consider the consequences if, at some point in time, the cannon is not used as originally intended?
You might start out launching potatoes...but what happens if you shift to steel slugs?
Or load the barrel with crushed gravel?

A blend of gas and O2 set to cut metal makes a very potent explosion....I'm not sure but may border on detonation.......???

IMHO.....you are on the edge of safety and entering the realm of diminishing returns for you .....and onlookers..
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Postby blackspire » Sat Oct 21, 2006 2:52 pm

What about a propane and oxygen mixture? Has anyone tried this before?
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