Well, I don't see any dangers with such small volumes of hydroxy gas. The only thing you can damage is probably your hearing. :)
And yes i plan on posting damage pics, however there was s little accident with the electrolyser(accidentally plugged the outlet tube and as the pressure build up it ...

I have a design that separates h2/o2, but haven't build it yet. It's basically two plates separated by a porous membrane. I don't know where you could find the membrane though.

Well, i've no idea who larda is, but i guess he's cool.

Not to be a killjoy - it's a lovely cannon... but you should be made aware of hydrogen embrittlement.
Many metals, but most notably steels, are severely weakened by contact with high(er) concentrations of hydrogen, as hydrogen diffuses into the metal, and forms tiny pockets of high pressures ...

Yep, the thing with light projectiles is totally true. A few times i tried shooting a long drill bit(bout 10 grams i guess). It didn't even come out of the barrel. Light projecticles like small nails and ball-bearings work fine though. And yes, stainless steel is expensive. I get it for cheap or ...

how do you know you have enough? is hydrogen safe to use in pvc or is it best to use metal? can you explain the electrolocis machine more.

1.A 40 sec run of the electrolyser is enough to fill the chamber.

2.The power of hydrogen is highly overrated and i think there won't be any problem using it ...

Oook , so here's the electrolyser:
Electrolyser Diagram
Electrolyser1
Electrolyser2
Electrolyser3


The whole thing is less than a foot high.For electrolyte i use baking soda. When i run it at 12v it puts out about 100cc/minute(haven't measured it though, just think so). There are a couple ...

he do not pressurize it. he just takes the air out and put hydrogen and oxygen in.

NICE gun there! expect some steel hybrids from you :)
yep, no pressure. only 1x
the gun is all stainless steel simply because i have easy access to s.s tubes, a welding machine, and i like s.s. It's not because of ...

we obviously misunderstood each other, so no it's not airtight. that's easily fixable though, but i think i'll just make another one (maybe bigger)

none but burst disc is a good idea especially considering the c/b ratio.may add one in the future

it is. completely 8)

Ok, so here's my stainless steel mini combustion. :)

Some specs:
Chamber volume: 40 cc/cm3
Chamber length: 1,5"
Chamber dia.:1,4"
Barrel volume: 3cc/cm3
Barrel length: 9"
Caliber: 0.08"
Ch/Brr ratio : 13
As you see there are 2 s.s tubes going in the chamber. The first is the hydrogen/oxygen mix ...