Stephen wrote:

> But have you ever tried to put burning magnesium out?
> 
> I remember from a fire fighting course I was on when I worked offshore that
> there is a technique for doing it. You have to pour copious amounts of water on
> it very slowly. Not use the normal jet from a fire hose or you have a very
> spread out fire. :)

Ummm. Water on a metal fire ... isn't that just going to exacerbate the 
reaction and create hydrogen gas?

Some will even burn in nitrogen.. I think they have foams for helping 
extinguish metal fires.

-- 
~Mike

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> Ummm. Water on a metal fire ... isn't that just going to exacerbate the 
> reaction and create hydrogen gas?

Not magnesium, no. (Not at any appreciable rate, at least.) Try it with, 
say, sodium and you've have a Big Problem. Magnesium is far too 
unreactive for it to be a problem.

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On Mon, 26 Jan 2009 08:53:30 -0600, Mike Raiford <"m[raiford]!at"@gmail.com>
wrote:

>Stephen wrote:
>
>> But have you ever tried to put burning magnesium out?
>> 
>> I remember from a fire fighting course I was on when I worked offshore that
>> there is a technique for doing it. You have to pour copious amounts of water on
>> it very slowly. Not use the normal jet from a fire hose or you have a very
>> spread out fire. :)
>
>Ummm. Water on a metal fire ... isn't that just going to exacerbate the 
>reaction and create hydrogen gas?
>
>Some will even burn in nitrogen.. I think they have foams for helping 
>extinguish metal fires.

Yes, but the obvious circumstances of a magnesium fire offshore is a helicopter
crash. The build up of Hydrogen would not be a problem as it would be outside or
on the helideck. We would have used AFFF (Aqueous film forming foam). The water
being mainly a carrier for the AFFF and for cooling.
-- 

Regards
     Stephen

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Invisible wrote:

> Not magnesium, no. (Not at any appreciable rate, at least.) Try it with, 
> say, sodium and you've have a Big Problem. Magnesium is far too 
> unreactive for it to be a problem.

But when the metal is at the combustion point it would react with the 
water, right?

Yes, right ... http://en.wikipedia.org/wiki/Magnesium#Precautions

The only way to douse the fire is to smother it. Water will simply piss 
it off.

Sodium reacts if you so much as look at it wrong...

-- 
~Mike

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Stephen wrote:

> Yes, but the obvious circumstances of a magnesium fire offshore is a helicopter
> crash. The build up of Hydrogen would not be a problem as it would be outside or
> on the helideck. We would have used AFFF (Aqueous film forming foam). The water
> being mainly a carrier for the AFFF and for cooling.

Just make sure its Class D. :)

-- 
~Mike

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>> Not magnesium, no. (Not at any appreciable rate, at least.) Try it 
>> with, say, sodium and you've have a Big Problem. Magnesium is far too 
>> unreactive for it to be a problem.
> 
> But when the metal is at the combustion point it would react with the 
> water, right?
> 
> Yes, right ... http://en.wikipedia.org/wiki/Magnesium#Precautions

Oh, well, I've only tried mixing it in water at room temperatures.

> Sodium reacts if you so much as look at it wrong...

Yes. ;-)

And calcium bubbles quite a bit.

And magnesium... well after about an hour a few tiny bubbles had formed 
on its surface. So I guess that's a sort-of reaction?

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Invisible wrote:

> And magnesium... well after about an hour a few tiny bubbles had formed 
> on its surface. So I guess that's a sort-of reaction?

Its every bit as much of a reaction as iron rusting ... yes.

-- 
~Mike

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>> And magnesium... well after about an hour a few tiny bubbles had 
>> formed on its surface. So I guess that's a sort-of reaction?
> 
> Its every bit as much of a reaction as iron rusting ... yes.

And about as much fun as watching iron resting... yes. :-)

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Invisible wrote:

> And about as much fun as watching iron resting... yes. :-)

Absolutely :D

-- 
~Mike

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>> And about as much fun as watching iron resting... yes. :-)
> 
> Absolutely :D

Or even "rusting"... :-}

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