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Posted: Wed Aug 15, 2007 3:16 pm
by paaiyan
Hydrogen peroxide is an indredient in a peroxide bomb. I don't remember the other ingredients, so you'll want to research that to make sure you'r enot making one. Basically, if you use those ingredients, the resulting byproducts are both shock and temperature sensitive. A guy at a campus near me put one in his backpack during a football game and waited on a park bench till it went off. If the stuff hits room temperature, boom. Just make sure you're not making that.
Posted: Wed Aug 15, 2007 3:26 pm
by DYI
Because platinum is very difficult to obtain, and prohibitively expensive.
If you do make this, it should be good. If you go with the oxygen reaction, make sure that you don't have anything in there that could react with the pressurised oxygen you will be creating. As Jimmy said, make sure you don't have anything that could react with the H2O2. Use a pressure gauge that is rated for service with corrosive fluids. As far as the pop-off valve, I don't know whether that will be feasible, or necessary.
You will either be producing steam, or oxygen, two of the most difficult fluids for complex equipment to survive. Steam rated pop-offs exist, but are expensive, and I don't know of any equivalent for oxygen. There are however, such things as premade rupture disks which are made of graphite and fit in flanges. They are expensive, but may be the only safe option here.
I would agree that you should use a burst disk valve for this. Try to make sure that the H2O2 doesn't come into contact with any parts that are not specifically made for corrosive service, and, if you value your life, DO NOT build this out of plastic pipe. I would go for a pressure rating of over 500 psi to be on the safe side. I believe that this cannon could be accomplished, but it will take some careful design work.
Good luck!
Posted: Wed Aug 15, 2007 4:09 pm
by Modderxtrordanare
Everyone in this thread should probably tread lightly, for the thread is on the edge of being against forum rules. I don't want anyone getting in trouble or this thread getting locked either.

Posted: Wed Aug 15, 2007 4:24 pm
by paaiyan
Hey, I was the voice of reason, I'm the one telling him it's a bad idea.
Posted: Wed Aug 15, 2007 4:57 pm
by thespeedycicada
i just found out silver is also an exeptable catalyst you just need to get it red hot to activate it and you dont need alot to get alot of steam.I really wouldnt mess with maganese dioxide or oxygen its not as effective and is more dangerous.At any rate be careful if you do this both reactions are not very safe AT ALL!! be careful.
Posted: Wed Aug 15, 2007 9:23 pm
by beebs111
make the silver in very fine strips. if by peroxide bomb, you mean AP or TATP, then he is far from making that.
Posted: Wed Aug 15, 2007 10:49 pm
by Hubb
Hydrogren peroxide (the real stuff at 30% to 35%) may need you to possess a special license to obtain due to its potential in making explosives. To get this license, you would probably have to go through the ATF, which would probably not be happy with this "experiment."
If you can get this stuff, good for you and I say go for it. Just make sure you take 'flinger's advise and make a metal cannon and burst disc.
One more thing to think about. The only good thing I see about this is the fact that it is pretty original, but would get expensive (more so than a tire valve and compressor) over time.
Anyways, good luck with this weird project and don't blow yourself up.
Posted: Thu Aug 16, 2007 2:26 am
by Killjoy
Hydrogren peroxide (the real stuff at 30% to 35%) may need you to possess a special license to obtain due to its potential in making explosives. To get this license, you would probably have to go through the ATF, which would probably not be happy with this "experiment."
A quick google search brought up multiple sites selling 35% hydrogen peroxide and none of them mentioned that a license was required (one was selling 4 gallons of 35% h2o2 for +100 bucks) . And I know a taxidermist who uses it to clean meat off the skulls of animals and he doesn't need a license to buy it. And I doubt ATF would be watching the sale of 35% Hydrogen Peroxide since it is used in so many things, they have bigger fish to fry.
Sounds like a good idea though, just be careful.
Posted: Thu Aug 16, 2007 1:13 pm
by jimmy101
1. Hydrogen peroxide at high concentations (above 70% or so) is an explosive and will auto detonate at temperatures above 160F, therefore it does burn/explode.
2. High concentration H2O2 spilled on clothing will evaporate the water first. The remaining H2O2, at very high concentration, will spontaneously ignite the clothing.
Hydrogen peroxide is a STRONG OXIDIZER, at <70% or so concentration it will not combust. It does generate oxygen which is half of what you need for combustion. At high enough oxygen concentrations darn near everything (PVC, steel, ...) will burn. So, H2O2 used to generate oxygen has the same safety issues as using straight oxygen. Straight oxygen is generally considered to be unsafe in a plastic gun.
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I wouldn't count on "I doubt ATF would be watching the sale of 35% Hydrogen Peroxide since it is used in so many things, they have bigger fish to fry." The ATF, and Homeland Security, sure as heck watch any unusual sales of nitrate fertilizer. I would certainly expect them to also be tracking H2O2 to the extent they can.
Posted: Thu Aug 16, 2007 7:12 pm
by Intel Xeon
I believe that metals need to be near molten to be "burned away" by oxygen. That is the principle behind cutting torches, yes? Solid u-pvc generally does not burn very easily, as it is a self-extinguishing material if I am not mistaken.
Regardless, don't mess around with chemicals for your first spud cannon. Like people before me have said, just use a tried and true method of filling.
Posted: Thu Aug 16, 2007 7:17 pm
by randompkguy
you gunna figure out how to remotely fire this thing? cause i recommend it

Posted: Thu Aug 16, 2007 11:00 pm
by mike1010
you could use some sort of glass container in the chamber and the crack the glass to make the reaction take place.
Posted: Thu Aug 16, 2007 11:46 pm
by frankrede
Intel Xeon wrote:I believe that metals need to be near molten to be "burned away" by oxygen. That is the principle behind cutting torches, yes? Solid u-pvc generally does not burn very easily, as it is a self-extinguishing material if I am not mistaken.
Regardless, don't mess around with chemicals for your first spud cannon. Like people before me have said, just use a tried and true method of filling.
Cutting torches hea the metal really hot then add oxygen to make it oxidize and then you burn away the oxidized metal.
Posted: Fri Aug 17, 2007 3:01 am
by thespeedycicada
mike1010 wrote:you could use some sort of glass container in the chamber and the crack the glass to make the reaction take place.
Yes but you might end up with hot glass flying out of the barrel if you mean break the glass in the chamber that is.I am not totally sure if this would happen but you would have broken glass in the chamber wich would be a pain to get out.
Posted: Fri Aug 17, 2007 4:03 am
by Redcoat
If you just wanted to make a cannon before they leave build an advanced combustion or a good pneumatic or hybrid.
Happy SPuddin'