Panel design

I saw the "Mythbusters" segment regarding this. In a small enclosed area they saturated the air with gasoline vapors and set up the cell phone. They called it and had a mechanism so it would place calls. No explosions in any of the tests.

Tom Jenkins said:

Actually the burning temperature of a cigarette is lower than the flash point of gasoline. You cannot start a fire with a burning cigarette - even if you hold it in the fumes. I watched my dad and brother fill our tractors with gas every day for over ten years with a lit cigarette hanging from their lips about 6" over the spout. This anecdotal evidence was later confirmed by a fire marshall.

On the other hand, a lit match or a lighter can certainly create some exciting moments - hence the prohibition on smoking. You just can't expect people to obey a "no lighting" rule!

Click to expand...

You can actually throw lit matches into a pail of gasoline as long as you wait for the fumes to fade first. So the first one will be extinguished but if you throw the second one too quickly after the first, it will ignite because it will have stirred up the gas creating more fumes. Freaked me out the first time I saw someone do it.

Tom Jenkins said:

I can't prove it, but I would be amazed if a cell phone had enough energy to ignite gasoline. Now, a loose electrical connection, particularly if the rascal is using the "cigarette lighter" charging plug in, could well have enough energy in a spark to set off fumes. I think this is another of those "we aren't sure so why take a chance" deals.

Click to expand...

That is what the cellphone rep was saying to the reporter in the report I saw.

Tom,

I'll take your word for that, but I'll reserve testing it again.

There's also an "Urban Legend" in town that Garfield Wood (aka GarWood), (old famous powerboat racer), once welded a cap on a full gas tank during a Gold Cup race. Theroy goes that the fumes burn, so the tank was filled to the brim and the cap was tacked down.

You can actually throw lit matches into a pail of gasoline as long as you wait for the fumes to fade first. So the first one will be extinguished but if you throw the second one too quickly after the first, it will ignite because it will have stirred up the gas creating more fumes. Freaked me out the first time I saw someone do it.

Click to expand...

I remember reading this when I was young - 12 - 14 or so - so I had to try it out - it's true (I'm glad to say!).

Well, I have to admit that I'm not interested in testing it unless I was at a pretty safe distance! There is obviously a huge difference of opinioin on these matters. Here are some related discussions:


http://www.snopes.com/autos/hazards/gasvapor.asp

http://www.physlink.com/Education/AskExperts/ae1.cfm

I'm not going to get into a huge discusssion, and of course there are circumstances and circumstances. I'm inclined to agree with the "full tanks don't explode" theory, too. My brother had a '36 "A" John Deere tractor, which had a leak at the fill neck he neglected to tell me about. I topped off the tank, and it leaked down the side of the tank. While making a turn a drop of gas fell on the magneto, and that John Deere was a rolling ball of flame instantly. I watched it run across the field (I do not remember jumping off, but obviously I must have!). When the plug wires burned through it stopped, and by the time the fire department got there the flames were out, having burned anything combustible. The full gas tank never blew.

Again this is an expirement I'm not anxious to repeat! Better safe than sorry!

Tom,

That is a great story! I have to agree with you that it is probably something you do not want to repeat again.

Bob

Damn it Tom!

Now you have given me another website to spend gobs of time on. Physlink is cool!

Just Finished the Texas A&M Fire School.......

I have not seen any discussion of LEL or UEL in any of these experiments.

The reason there is such confusion about ignition of gas by a cigarette probably has to do with Lower Explosive Limit and Upper Explosive Limit. Lower Explosive Limit (or LEL) is the minimal amount of gas fumes required to ignite at a given temperature. If you have below the LEL you'll get no ignition. Upper Explosive Limit works the same way, when the Upper Explosive Limit is reached, there is actually too much gas vapor (not enough air) to ignite the gas. In other words the mixture is too rich.

Just so everybody knows, It's the gas fumes that burn, not the liquid. A lit cigarette will in fact ignite gas, as long as the gas to oxygen ratio has not reached the UEL and gas is above the LEL. If this balance is not reached, the liquid gas the cigarette lands in will snuff the tip.

Does anybody have any links to that particular "Mythbusters" video?

I uploaded the interview with Jamie and Adam from last month on the Opie & Anthony XM satellite radio show. They talked about the cell phone episode. Some good 'behind the scenes' info for Mythbusters fans. About 40 minutes long...

http://www.patchn.com/files/ericn/videos/Mythbusters-O&A.mp3

Contrary to what you'd expect from O&A, this interview is actually (amazingly!) safe for all audiences... :nodi:



-Eric