I know that gas is flammable in the correct mixture with air. So if I were to dump a cup of gasoline on a flame from a short distance, I would wind up with a big flash, no arm hair, and possibly an ambulance ride.
But if there were a way to deliver the gasoline to the flame without creating vapor or an air/fuel mix, (say, like… a water balloon filled with gasoline) would the liquid mass of the liquid gasoline extinguish the flame and not ignite?
Sounds reasonable. You can probably extinquish a match by dumping a cup of gasoline on it. Besides smothering the flame, the gasoline will absorb heat, another component necessary for a fire. But if a little bit of flame sneaks around the outside of the mass of gasoline you dump…
I’ve done it (when I was too young to know how risky such an experiment was). I extinquished a small ashtray sized fire (within a campfire pit) with about 12 oz of gasoline. Extinguishing cigarettes in a cup of gasoline is another juvenile trick we performed.
Couldn’t find a cite for this, but there was a publicized incident some years back where the NYC firefighters exam gave partial credit for a question about how to put out a fire. One of the choices was throw a bucket of gasoline on the fire. The logic behind giving credit was supposed to be that you demonstrated the knowledge that you throw things on fires to put them out:dubious:
Putting out a cigarette with gasoline works pretty well because the glowing end of the cigarette is barely hot enough to ignite gasoline vapor in the proper mixture of air. An actual flame though is a gaseous plasma that is hotter and more fluid and could ignite gasoline easily. Just a small pocket where the fuel and air mix in the proper amounts could cause it all to go up in a flash. And if a hot coal were knocked out of the fire as a result of dumping gasoline on it, it could easily ignite the gasoline that splashes, spills, and vaporizes in the area. If you try this, please get someone to videotape it 
Maybe in a small enclosed container, where the gasoline will displace all the air?
So, a five-gallon can with a small opening,and something heavy in the bottom of the can burning not too fiercely. If you can quickly pump the can full of gasoline, you might be able to fill it full of cool gasoline quickly enough to smother/cool the original fire, while any vapors that ignite are quickly pushed up out of the can by the rising level of liquid gasoline. Fill it up to the very small opening at the top, and you could quite possibly have a whole can of gasoline cool enough to stay unoxidized.
I’m not saying I’m confident enough to test this except from a distance, but it’s at least possible. It would be kind of fun to test, though… anyone have Adam or Jamie’s phone number?
I posted this because I assumed someone else would try it and put it on video, saving me the embarrassment of screaming at my husband: “put me out! I’m on fire!!”
David Bowie says he’s done it - “Cat People”.
With the reply video “Where are my eyebrows?”
I too have seen cigarettes snuffed in a cup of gasoline. I do not recommend trying it but it can be done.
Fire needs three things to burn:
Break any one of those three legs and the fire goes out.
Gasoline will not burn by itself. It needs to be mixed with air. There is a stoichiometric ratio for any fuel which defines its ideal air/fuel mixture to burn the best. You can go outside that ratio to some extent but get too far out and no fire.
The problem with snuffing a match with gasoline is there is probably some gasoline vapor that has evaporated sitting on the surface of the gasoline. That may be enough to catch fire making the practice risky. Still, can be done.
Is anything added to gas to make it less combustible outside of an engine? I’ve seen people fill their tanks while smoking and/or talking on a cell and never have been caught in a fireball. Which was nice as I was sitting in the car being filled, during those times.
You can find videos of gasoline being ignited accidently by people filling their cars.
Kari Byron: On tonight’s Mythbusters, we’re going to set Grant on fire and see if we can’t put him out with some gasoline. Please don’t try this at home, we’re what you call experts.
You might be able to use the oil rig fire technique by vaporizing or aerosoling a lot of gasoline near the fire and triggering a rapid deflagration that consumes all the available oxygen in the area starving the fire, or blows out the fire from the pressure wave. Please, please, make a videotape if you try this one.
Not really.
As mentioned stoichiometrics is the study of what an ideal fuel/air mixture is. That ideal is different for different fuels (e.g. gasoline or natural gas, etc.). For gasoline you may have heard people mention an engine is running too lean or too rich. That is when the ideal gas/air mixture is off one way or the other. Eventually though, if you get too far out of the ideal, the mixture will not combust.
In the case of a gas station, while you can smell the gas, it is far too dilute to explode so it is possible to smoke while filling your car. However, if things conspired just right the potential for a catastrophic explosion exists. While very unlikely at a gas station a fuel/air explosion can be particularly devastating. The largest non-nuclear weapon in the world (the FOAB…Father Of All Bombs) is a thermobaric (fuel/air) bomb. It is said to have a yield around that of a small tactical nuclear weapon. A gas station wouldn’t be that powerful but the damage can potentially be considerable.
As such it is best to avoid smoking in the vicinity of gasoline. You could do a lot worse than singe your eyebrows.
Don’t need to. Gasoline isn’t particularly easy to ignite. Part of why it became the vehicle fuel of choice. Good energy density and relatively safe in an accident. With that said, fueling is one of the most dangerous times as the the potential for a combustible concentration of vapors goes way up.
Gasoline vapors have a very narrow combustible mixture range in air, which means you can have a fuel pump in a closed container like an automotive gas tank and not have much concern about fire. The vapor density is much much too high to be combustible. On the other hand hydrogen is combustible in almost any mixture density.
Lower and Upper Explosive limits by % in air
Gasoline 1.4 - 7.6
Hydrogen 4 - 75
DTTAH but if you take half a soup can of cold gasoline and don’t like it sit for long before lighting it, you get a very mild flame across the surface. The liquid can’t burn and there isn’t much surface area to allow the liquid to evaporate.
I recall an old Ripley’s Believe it or Not cartoon that claimed that they used to use gasoline to put out fires (smoldering ones, presumably) in the center of compressed bales of cotton. The idea is that there’s not much air in the tightly=packed fiber, and the gasoline apparently penetrates more rapidly than water and cuts off air from the smoldereing material, quenching the flame.
So if your fire is a slow smoulder in an air-starved situation and gasoline can easily penetrate, that would be a circumstance where you could use gasoline to put out the fire.
This is too similar to the thread title – is this was sugested the question?
And if it doesn’t work, they’ll just blow him up at the end.
It is a new golden age for television.
And it’s been reported here on the SDMBtoo! That’s a pretty cool (and potentially viral video inducing) factoid.
Well, you know what they say. If you can’t confirm the myth, then replicate the results.