Fire extinguishers

[PyroMan LTU]

Hello,

 

I am getting a fire extinguisher soon I wanted to discuss wich are the best? There are few types (Co2, powder, water), so If chems catch fire what is the best choice, obviously having a bucket of water will always be helpful, but as far as I know mg fire is fairly impossible to extingwish becouse it reacts with everything so for chems like pvc, kcl3, sr(no3)2, red gum or stars etc... of courese if few baches of stars catches fire it will be nearly impossible to stop it, due to the flame and smoke... but anyhow qestion is - wich is the best? Thanks

 

PyroMan LTU

[Puriss]

All fires with metalfuels are hard to extinguish. If you put water on a fire like that, burning hot slag will scatter

and the fire will become worse. I use a metalbucket with a little dampen sand in case of something catching fire, it´s my first choise, trying to get the fire out of my workingplace. The fire extinguishers have different function trying to kill the fire.

 

Water:cooling, suffocating.

C02:little cooling, suffocating.

Powder:suffocating

 

It´s almost impossible to take out a red-ox fire trying to suffocate it, because it produce its own oxygen.

The firefighter normaly use foam when they take out chemical fires. The foam cools the fire and form a film over the burning area which normaly is very effective in the most chemical fires. Fires containing metalfuels are almost impossible to take out, the best way is to move the burning slag to a safe place where it can burn out and try to move all unburned material far away from the fire.

[mike_au]

CO2 and dry powder both work by excluding oxygen and smothering the fire. Obviously that won't work for anything that has its own oxidizer. Water will absorb energy and extinguish comps, but it may also react and cause more problems than it solves (e.g. Mg fire).

 

I have a couple of water extinguishers near my work bench, you just have to make sure you think before you use it.

 

If I was about to make up a batch of magnalium or anything I would go grab the dry powder one out of my car.

 

 

EDIT:

 

 

Puriss: If working with molten metal, the sand should not be wet.

Edited April 4, 2009 by mike_au

[PyroMan LTU]

well, sand probably might be the best application, only exeption that sand as it is metal oxide SiO2 it can burn combination with aluminium as a thermite...

[al93535]

Well I always carry an ABC fire extinguisher with me while I test or do small shoots. For larger ones I carry several and we have water available. This is however ONLY for fires started by pyrotechnics.

 

In commercial practice there are NO extinguishers allowed in any production buildings at all!! Why? Because it is absolutely fruitless and stupid to try to attack a pyro fueled fire. There are none present to prevent the initial response of grabbing the thing and trying, if its not there you wont try. Just get out of the building, if you can. These fires are so vicious and unimaginable, you can't ever be really prepared for an accident indoors. We do burns of our fireworks trash every now and then, and man, it makes you respect what you are handling.

 

In home use, well, there is a split decision. In all reality for your safety you should just run, dont event try. However, its probably your home or shop, and you are working with small amounts of comp less then 10 lbs at a time. The comp would flash off pretty fast leaving remaining fires that you actually could put out easily with an ABC extinguisher.

 

Small batches of just chemicals can be extinguished with an ABC type. Most hobbyists will have minimal amounts under 3 lbs of each so... However, I would let any magnesium or aluminum fires burn out and put out the resulting fires.

 

So I would have to say, two extinguishers... both the largest ABC ones you can get. One right by the exit, so you can reach back inside after you exited the building, then start using it. And another inside NOT right next to where you work. (you cant grab a hot metal can)

[Swede]

Halogen-based extiguishers I think are the best, but you can no longer buy them at "Bill's Hardware Store" down the road. Apparently they deplete the ozone layer, and they are used now on commercial aircraft to put out fires in engines and such. In cases like that, you often have Ti and Al burning or melting.

 

But here is a little known tidbit... civilian-types can still buy halogen extinguishers. They are sold to equip the cabins of general aviation aircraft. If you go to a sight that sells pilot supplies, you'll often find them. Not cheap, but I think they are the best all-around extinguishers out there.

[Ventsi]

A friend of mine was talking to me about his friend being a firefighter.

 

 

They had special fire extinguishers called Metal X which were a bright yellow.

 

Supposedly these could put out any metal fire Mg/Al/Ti.

 

 

I’m not sure if they are what Swede is talking about , they might very well be.

 

His friend was called to put out a Porsche [Mg engine} that had caught fire.

 

They didn’t have one of these on them at the time and all they could do is watch it burn through the car, through the asphalt and in the ground.

Edited April 4, 2009 by Ventsi

[Mumbles]

They're also called class D fire extinguishers. They contain NaCl. The magnesium/aluminum/titanium/whatever can't displace the sodium. I'd assume they simply smother the fire, so I don't know how it'd work with metal fires containing it's own oxygen source. Then again, outside of MgAl production, the chances of us starting metal fires that burnt long enough to allow us to get said extinguisher are minimal.

[FrankRizzo]

Halogen-based extiguishers I think are the best, but you can no longer buy them at "Bill's Hardware Store" down the road. Apparently they deplete the ozone layer, and they are used now on commercial aircraft to put out fires in engines and such. In cases like that, you often have Ti and Al burning or melting.

 

But here is a little known tidbit... civilian-types can still buy halogen extinguishers. They are sold to equip the cabins of general aviation aircraft. If you go to a sight that sells pilot supplies, you'll often find them. Not cheap, but I think they are the best all-around extinguishers out there.

 

The best course of action is, of course, prevention. Limiting the amount of live material and finished items in your workspace at any given time will significantly reduce the risk of major catastrophe. If you do have an accident, having a simple pressurized water extinguisher to put out spot fires is probably the best idea. I like to keep a charged garden hose handy if the location permits.

 

I supervise the operation of a medium-sized server room, and we have Halon 1211 extinguishers all over the place. Last time the fire dept came through for the inspection, the guy told me that Halon (1211 and 1301) were not being produced anymore. There is some new alternative called Halotron that are supposed to be non ozone depleting, but it doesn't work near as well as the old stuff.

Edited April 4, 2009 by FrankRizzo

[Swede]

You may be right, Frank, but this may be a case where stockpiles are still being sold. Here's a Halon 1211, purportedly for a racing car:

 

http://www.pegasusautoracing.com/productde...s.asp?RecId=439

 

$120!! Wow. Not sure if it's worth it. I still have my small halon bottle from years ago in my shop. The pressure's still up, but it wouldn't pass any sort of inspection.

 

Interesting page on Halon vs. some other agents:

http://www.halonmarketing.com/mall/prod01.php

 

I tend to agree with the concensus... RUUUUNNNNN!

Edited April 5, 2009 by Swede

[Arthur]

Yes Class D (metal) fires are hard (to impossible) to extinguish. Simple metals May extinguish with a dry powder of Mg halide or Na halide. This forms a cooling, smothering blanket over the fire site excluding atmospheric oxygen. If the mix contains oxidisers, it's going to burn regardless but smothering it may limit the spread of damage.

[TheSidewinder]

Another drawback of using Halon is that for it to be effective, it has to reach a certain percentage of the ambient air before it will start working.

 

Inside a server room? Easily accomplished.

 

In a garage, or other location, with an open door? Not so easy (or flat-out impossible).

 

Outdoors in an open work area? Forget it. Far better to simply RUN.

[cojonesm]

It might be an idea to hang down some bags of water above your desk. They use this in China.

 

edit: You can also put sand in the bags, when the fire reaches the bags they'll melt down and the sand/water will extinguish your fire hopefully.

Edited July 29, 2009 by cojonesm

[Arthur]

Halons are being withdrawn from most uses inc aircraft and switch/server rooms as the halon itself is one of the major ozone depleting halocarbons.

 

Fire is going to happen sooner or later so minimise the flamable content of your work area. Put lids on store jars cut the fuse you need then put the rest back into a fire retardant container.

[inonickname]

I'd choose a Halon one, but that's rarely an option due to ozone being weak as.

 

Of course metal fires containing their own oxidizers are nigh on impossible to put out, hell; you can tip liquid nitrogen on thermite and all you will get is horrible burns. (Any fire with it's own oxidizer is hard to put out)

 

Some metal fires can splice things like water and carbon dioxide to get the oxygen needed for combustion, so they are out. (by the way, most thermites will split water straight to hydrogen and oxygen, not oxygen and a hydroxide (bad).)

 

Dry powder is the way to go. It smothers the fire, which is really the best option.

 

Though given the kind of things dealt with in average pyro I'd just have a dry powder extinguisher, and instead of reaching for it when something appears to be lighting remove as much flammable material as you can, and get out. Then use it to put out any small fires that could have started on benches et cetera.

 

For example, while testing a (small) amount of BP in the shed it flashed to the packet (which I had not realized had tipped over-zippy ftl), creating lots of small fires (fast) everywhere. Reaching for the extinguisher (which I don't think was dry powder) would have only caused the fires to spread around. I just let it burn, making sure nothing else could catch fire. I just vented the shed out and put out a fire on a container of sawdust that had begun to smoulder.

 

Edit: I don't think it was BP, it may have been a slow star mix

Edited July 30, 2009 by inonickname