Safety - Combustable Gasses & Vapours

El Brenty · Post by **El Brenty** » Sun Dec 07, 2003 12:54 pm

When you're using combustable gasses, you have to bear a few things in mind:

- Combustable gasses need oxygen to burn. If there's insufficient oxygen available in the mix, the combustion will be feeble. Oxygen is not combustable, but provides the combustion for combustable gasses (If that makes any sense).

- When burning pressurised gasses (Like inside a balloon), make sure that pressure of the escaping gas won't extinguish the pilot light. Don't forget that they use explosives to put out oil and gas well fires! You'd think that would be the last thing to use with oil!

- Be careful when pressurising combustable gasses. WHen the container (Balloon?) bursts, it won't distribute the gas evenly, and the rupture could be nearer to you.

- ALWAYS HAVE A FIRE EXTINGUISHER HANDY! A CO2 one is probably best for gaseous fires, as water may interfere with electrical detonators and the like.

- Rehearse explosions time and time again, don't just plan a big one as a one-off. This is especially the case if actors are nearby in the scene.

- Use my special detonator system for multiple and timed detonations (That I promise I will post on here shortly).

- If you're planning some reasonably big explosions, like exploding the garden shed, get in touch with your local fire brigade. They will be more than happy to lend assistance, and may even advise on what the best method to do the explosion is. This is probably a good idea if you have neighbours nearby, because chances are when one of them sees smoke, they'll call the fire brigade for you, and then you have to start explaining yourself afterwards!

- Many combustable gasses are available from industrial gas suppliers (Often through hire shops). You can pick them up easily, buf if you're using these, follow safety guidelines with cylinders - The heavy steel ones are often filled to pressures of 3000psi+, and if one of them topples over and snaps the valve, it'll literally launch itself like a rocket and stop at nothing! The helium ones we use weigh about 70kg, and can launch themselves about 75ft into the air! No-one wants to be around if this happens! A car tyre's pressure is about 35psi! BIG difference!

- With cylinders, always use a proper regulator to lower the outlet pressure. If you don't, you can easily lose an eye from the force of the gas coming out.

- Always ensure you have adequate ventillation around you when dealing with combustable gasses. Many of them are toxic, don't have any smell, and can be asphyxiants. The Helium we use for balloons is an asphyxiant, and if you're not careful and breathe too much in, you'll just keel over from oxygen deprivation. Worst case - get brain damage, or die!

- On the subject of Helium, if you're going to breathe in helium from balloons, don't! There's several reasons for this: Latex balloons are filled with a very fine powder to stop them sticking, and this is bad for your lungs if you breathe too much in. Also the Helium is an asphyxiant, as mentioned above. If you really HAVE to breathe in Helium, take a few deep breaths first to get some oxygen circulating around your body. The squeaky voice effect will work exactly the same, but at least you won't have displaced so much oxygen.

- Liquids like Petrol burn badly. However, it's their vapours that burn like crazy, and if you get the air/vapour mix right, you'll get big explosions. Start off small, practice, and work up to the effect you're trying to get.

- Don't smoke near combustable gasses! Sounds obvious, but if you sometimes can't smell the gas, you may not realise it's still present!

Always think safety! You can still achieve good movie effects, but put a bit of thought into them!

Grant · Post by **Grant** » Sun Dec 07, 2003 11:54 pm

yes Sir

El Brenty · Post by **El Brenty** » Mon Dec 08, 2003 12:28 am

Well, you know!

When I started typing that it was only going to be a few lines long, but you know me when I get going!

Ivan Speilberg · Post by **Ivan Speilberg** » Wed Dec 17, 2003 2:33 pm

Pure oxigen is veeeeeeeeeery combustible. The oxigen we normally breathe is mixed with other gases, that's why it doesn't burn w/o a heat source and combustible.

You have been making promises of posting your special detonator for a looooooooooooooooong time now, it better be a good one!!!!!!!!!!!
WHEN THE F**K ARE YOU GONA POST IT???????????????? We need it!! (At least I do!!!)

foxwood · Post by **foxwood** » Wed Dec 17, 2003 6:26 pm

You wouldn't happon to be talking about this one would you? http://www.matthawkins.co.uk/forum/viewtopic.php?t=2215

El Brenty · Post by **El Brenty** » Wed Dec 17, 2003 8:55 pm

Ivan Speilberg wrote:Pure oxigen is veeeeeeeeeery combustible. The oxigen we normally breathe is mixed with other gases, that's why it doesn't burn w/o a heat source and combustible.

You have been making promises of posting your special detonator for a looooooooooooooooong time now, it better be a good one!!!!!!!!!!!
WHEN THE F**K ARE YOU GONA POST IT???????????????? We need it!! (At least I do!!!)

Yep, just follow the link Foxwood posted, The document is in the tutorials section, and there's an accompanying article for turning party-poppers into squibs!

Hope you like!

Raptor · Post by **Raptor** » Wed Dec 17, 2003 9:41 pm

Ivan Speilberg wrote:Pure oxigen is veeeeeeeeeery combustible. The oxigen we normally breathe is mixed with other gases, that's why it doesn't burn w/o a heat source and combustible.

You have been making promises of posting your special detonator for a looooooooooooooooong time now, it better be a good one!!!!!!!!!!!
WHEN THE F**K ARE YOU GONA POST IT???????????????? We need it!! (At least I do!!!)

Actually Oxygen will not ignite at all..... it will however in sufficient concentration cause any other fuel near it burn rapidly and intensely... the oxygen itself however only acts as the oxidizer for the reaction...

Ivan Speilberg · Post by **Ivan Speilberg** » Thu Dec 18, 2003 5:57 pm

Actually Oxygen will not ignite at all..... it will however in sufficient concentration cause any other fuel near it burn rapidly and intensely... the oxygen itself however only acts as the oxidizer for the reaction...

YEP!!!
And tanks for the igniter link Foxwood

I was unable to open it directly, my PC just wouldn't open it(Don't ask me why)

I found it a short time after I posted the reply.
Thanks a lot for the link, it's a gooooooood detonator!!!!!

El Brenty · Post by **El Brenty** » Thu Dec 18, 2003 6:24 pm

You silly so and sos, didn't I say right at the beginning : "- Combustable gasses need oxygen to burn... ...Oxygen is not combustable, but provides the combustion for combustable gasses (If that makes any sense). "

What are you lot like!

I did do A-Level Chemistry you know!