Quote:
Originally posted by BoomTruck
You do NOT, repeat NOT want to do that!
PVC or ABS gets brittle when it gets gold. When you turn liquid CO2 (as it is in a bottle) into gas (as it is when it comes out of said bottle), it is extremely cold. That is why regulators will ice up on MIG welders when they are under constant use.
Dumping extremely cold gas into a spudgun and then dumping the pressure again (losing even more temperature) is going to make the entire thing very cold, very fast. Not good.
You want fast air, get a compressor. DO NOT use bottled gases.
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Okay, now that is an interesting point. I had realized it was going to get cold, but didn't realize it was going to get so cold that it would affect PVC/ABS that way. Damnit. When I go out to a field I don't have any way to carry a compressor nor the powersupply to power said compressor. I was hoping bottled compressed gas could offer a nice portable solution. But I see now that that maybe isn't such a good idea afterall. Thanks for the heads up.
But I seem to find quite some people on the 'net that suggest CO2 for their spud guns:
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http://www.valuelinx.net/~dthames/carl.htm
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http://www.totse.com/en/bad_ideas/gu.../spudshot.html
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http://www.xinventions.com/main/spud/home.htm
Are these people's guns accidents waiting to happen? Does it really get cold enough for the PVC/ABS to be affected?
I would be using it first on my water rocket installation anyways. The whole thing uses copper tubing and PET bottles. I don't think it could be such a big problem there? I would take all the regular precautions there at any rate: pressure testing the bottle filled with water beforehand, to see at what pressure it fails, and using a long hose to have enough distance between bottle and myself. I haven't actually built the spud gun yet, for lack of suitable parts.