sean.hwy

Iride01 thanks for sharing


just to be clear you where clean parts outside ( not in the garage ) 22 feet from the water heater and still caught on fire?

Hondo6

I'll let @Iride01 confirm, but that is plausible. (I read it as him being at or just inside the garage door, but I could easily be wrong.)

If there was a slight breeze blowing into the garage, the gasoline vapor would have been largely pushed that way - particularly if there was an open window/vent/some other way other than the door for air to egress the closet, like an opening into the attic. Air being lighter than gasoline vapor, the gasoline vapor would have displaced air near the ground. It would have continued doing that until it reached the closet, then started filling the closet. Add a spark in the closet from, say, a water heater thermostat and things can get . . . interesting.

Many people have no concept of just how much stored chemical energy there is in gasoline, and what can happen when that energy is released. By weight, gasoline has between just under 9x and 10+x the energy content of TNT. Vaporize a chunk of gasoline, mix it with air in the proper ratio, and provide an ignition source and you can indeed get a sudden flare - technically, a deflagration, if I recall correctly (a detonation technically propagates at > the speed of sound, while a deflagration remains subsonic). In practice, there's not that much difference between the two; both can cause a very sudden large rise in both temperature and pressure.

My own bad experience with gasoline was more due to my own carelessness and/or simply not thinking things through. But I can certainly say this: having the world turn bright orange because your head is surrounded by the flames of a gasoline flare gets your freaking attention, even if blind luck (or perhaps Divine Intervention) meant I got nothing more than singed eyebrows and a slightly reddened face.

Iride01 

Yes, both I and the pan of gasoline was just outside the front of the garage with the big garage door open. I moved from that house a long time ago, but I think the 22 foot distance from both me and the pan to the water heater closet is about right. I was using a low sided metal pan much like the round plastic pans DIYer's use today to drain oil into from their motor vehicles.

And note that this was a electric water heater. There was no gas supply for any house in this particular neighborhood. It was entirely electric. So that was another surprise that the relay or whatever in the water heater made enough spark to set off the fumes. The only other thing in that area that might have made a spark was the circuit breaker panel that is also in the same closet. However it was probably about 4 feet of more off the floor level.

I'd heard all my life how gasoline vapors behave in a manner that is totally unexpected. And certainly they did this time. I'd seen gasoline fumes do similar once in my life when very young and my Mom used it to start a pile of brush and limbs on fire. However I was apparently to young to learn from that experience which I remember seeing a ghostly trail of flames going from the brush pile to the gas can that was well away from the fire. It wasn't spilled gasoline; it was just the fumes that had come from the can as it sat there.