SpudFiles

*Pulls out gaseq*

O2-H2 = 9.5 atm max pressure
air-H2 = 7.9 atm
O2-propane = 18.2 atm
air-propane = 9.1 atm

...so I don't see much motivation at all to use H2-O2.
(other than the increased burn rate and thus increased efficiency... but we could do that with a good spark strip, no?)

The thing is propane burns but Hydrogen + Oxygen detonates thus creating higher pressure spike and sends projectiles flying faster. I have a mini combustion cannon that shoots bbs and I use Hydrogen in it. I can shoot through 5 cans in a row with plastic bb. The chamber is only 1" by 1". If you ever decide on using Hydrogen use small chambers.

how do you get the hydrogen for that? electrolosys?

im thinking the chamber is going to be made out of some 2" black iron (or is it steel) pipe, i would make it larger but i doubt i can get anything with a larger diameter at home depot or lowes (if i order some massive pipe online my parents will be suspicious and it will cost a crap load to ship). and i had no idea an airsoft could even have enough power to go through 5 cans, thats insane, any idea on the bb's velocity? and how did you get the right mix on such a small chamber?

DON'T USE STEEL!!!
The hydrogen reacts with the carbon and makes it brittle.

DON'T USE STEEL!!!
The hydrogen reacts with the carbon and makes it brittle.

God damn it you double posted, oh well who cares.
Yeah ive heard the same thing about hydrogen's affects on steel. What about galvinized steel though, as far as i know Hydrogen doesn't have any affect on zinc, and if thats true then he could use galvinzed steel pipe from lowes or home depot.

ARRRGH! I hate it when that happens! When I hit submit it said 'this page cannot be displayed' so I clicked back then hit submit again. It must have gone through both times.

Yeah I think galvinized steel would work. What about copper?

I was thinking about this in class to day, I may sound like an idiot saying this, but hydrogen is lighter than oxygen, so would they separate and have hydrogen on the upper part on the chamber and oxygen on the lower part? Or would they mix up?

Shock waves apply force for only a minute amount of time - and so have a really hard time transferring meaningful energy.
Not saying they don't contribute, but I have a hard time believing that it's a significant effect... perhaps you would like to try the same penetration tests without the barrel?

Besides, like all energetic substances/mixtures, it takes time to transition from normal combustion to detonation... by memory, significantly more than the size of you chamber.

I know this thread's kinda old but i think it's important for y'all to know about mixing pure hydrogen with pure oxygen. It can be dangerous. Check out this site.

http://www.stevespanglerscience.com/experiment/00000102

If you do the electrolysis dirrectly in the chamber then you will already have a perfect (forgot the word... stechiomatic?? haha i tried) mix... 2 parts H and 1 part oxygen... Aka water

I tried it to night in one of my minis by turning my spark gap into electrodes for the electrolysis stage... but it needs separate, spark gap and electrodes because the electrolysis just corodes and craps up the metals... i'm experimenting with building a complete collection rig... i have seen some great ideas...

heres the rig im planning on building
it will contain a sealed electrolysis chamber with only a hose going out of the top.. it will be water tight... it will have a multi plate electrode set up run off of a power supply at 12 v... there will be a tube that goes straight up out of the top of the bottle that leads to a collection bowl... this will have and upside down bottle in it to catch the bubble that bubble into the chamber... the whole system will be flooded... this way the water will but turned to O2, H, NA, and Cl2 (the products of electrolysis with distilled water and table salt) i know cl2 isnt good for you... but its not large scale... then all the gasses will go up the tube into the water filled `chamber and into the collection bottle... this way it will force out the water and replace it with just what i need.

Look up Joe Cell and see how that is built. It is the best way to collect hydrogen + oxygen. Yes after the electrolisys it is in stochiometric stage.

Yea looks a bit more complicated then im looking for.... i saw this set up on you tube... it looks pretty good

what do you recommend for voltages... im thinking using a car battery charger because i don't have a medium voltage PSU

ah, reminding me of my favorite unit in chemistry.....stoichiometry!