What is the best type of Fire Extinguisher?

[Shoepop]

Would never leave home without it. 67s with Halguard 2.5# Halotron1.

[group911@aol.co]

After doing it for 30 some years, AFFF is the best. Prior post said something about corrosion but I've never seen it. We fill them by hand and get it all over including our hands with no ill effects - so far. It will also put out rubber fires including tires. I've used it on a pickup full of tires fully involved and put them out with one 2.5 gallon extinguisher - something that we would normally dump all 500 gallons in our tank and probably not get out.
Dry chem is corrosive and does as much damage as the fire - unless you have nothing else.
In a contained area, halon or CO2 work by depriving the fire of oxygen so the closed hood method would make it more effective.
I keep AFFF, CO2 and dry chem in my shop and would grab the cry chem last.

[9er]

I dont think a foam extinguisher is practical to mount inside a car, they are 94% water and are great in certain situations, certainly NOT where electricity is involved. Dry powder in most instances is just sodium bicarb and shouldn't present any problem with clean up or damage. But since you guys are still allowed CFCs (halons) they provide the best all round car solution, but are the enemy of the ozone layer.

[lucittm]

OK, something I know a little bit about.
First, no fire extinguisher does everything well, you have to figure out what the goal is.
Hint: electrical conduction fires "C" are usually not serious if you can remove the power. The exception is if the electrical fire causes another type of fire. Fires that leave an ash "A" are pretty easy to put out and if you are working on a car fire type "A" materials are carpets, seats, and human beings (we used to call them screaming alfa's). The biggies are flammable liquids "B" and flammable metals "D". The liquids are oil and gas, of course. The metal is magnesium. We have engine parts made of magnesium and there is no way to put out a metal fire because they make their own oxygen and they are very hot.

Second, let's concentrate on liquid fires, the ones that destroy our cars. Aqueous Film Forming Foam (AFFF) is the best but very hard to carry around in the car (that was mentioned before). Also, it has a shelf life and you need enough to prevent a re-flash. I have seen a guy step in a puddle of it and the fire erupted when he lifted his boot. Finally, it has no use on electrical fires and almost useless on type "A" fires. The gases: CO2, Halon, and water fog spray work pretty well but you have to get the fire completely out at close range and hope the surfaces are cool otherwise Poof, a re-flash.

Third, what to use? Powder, but not just any powder. Baking soda works in the kitchen but sodium bicarbonate is not very good at removing the oxygen (smothering) it is slightly better than salt. So we want something that smothers the fire, does not conduct electricity, and not as corrosive as some other agents. General purpose dry chemical extinguishers use monoammonium phosphate, nasty stuff. So, use what the Navy uses on their ships, Purple K Powder (PKP) or potassium bicarbonate.

From Wikipedia:
"Purple-K is a dry chemical fire suppression agent used in some dry powder fire extinguishers. It is the most effective dry chemical in fighting class B (flammable liquid) fires, and can be used against some energized electrical equipment fires (USA class C fires). It has about 4–5 times more effective against class B fires than carbon dioxide, and more than twice that of sodium bicarbonate. Some fire extinguishers are capable of operation in temperatures down to −54 °C or up to +49 °C. Dry Chemical Powder works by directly inhibiting the chemical chain reaction which forms one of the four sides of the fire tetrahedron (Heat + Oxygen + Fuel + Chemical Chain Reaction = Fire). To a much smaller degree it also has a smothering effect—excluding oxygen from the fire."

I have a 10lb bottle of PKP in my car (it fits on a Brey-Krause mount). If you ever have an engine fire, you will be glad if I pull up behind you because I have a 20 foot range and 24 seconds of discharge time. You can get PKP extinguishers at places like this:
http://www.safetysupercenter.com/Amerex-10-lb-Purple-K-Fire-Extinguisher-p/b460.htm
and
Ansul Sentry 10lb. Purple K Fire Extinguisher - Monroe Extinguisher

More expensive that a 2.5 lb can of baking soda, but inexpensive insurance to me.

Mark

[James Brown]

Nice write up Mark. get the fire early and overpower it.

[turbo3six]

[QUOTE=group911@aol.co;5716524]"Dry chem is corrosive and does as much damage as the fire - unless you have nothing else." QUOTE]

I'm not a fire expert and fortunately have never had a car catch fire...but I suspect it is not all that uncommon. There is some great info shared here from some very knowledgeable Pelicans.
I suspect many 911 owners carry a dry chem extinguisher. To suffer or actually cause additional damage from the dry chem would be a shame. It would seem that the most probable type of fire we would experience in our cars would be result of a fuel leak causing fire in the engine bay area. If this type of fire is noticed and fought with the right extinguisher it is more likely than not that the fire would be successfully and permanently suppressed.

It also seems that to have the best chance of successfully and permanently extinguishing a fire where the primary ignition or origin is electrical, a battery quick disconnect should be installed. Many of us already have some type of battery disconnect in order to preserve battery life when not in use.

[cashflyer]

One thing that many people forget is that the agent in dry powder extinguishers will "settle" and pack. This is especially true in vibration prone installations.

You need to take the extinguisher out and shake it up occasionally.
Otherwise when you need it, it could be useless.

This was what the fire inspectors told me about the dry chem extinguishers we have mounted in our shop.



Have any of you thought about an on-board system?
Seems like that would be the quickest and most effective response to a fire.

[JHanson]

Mark, thanks for a very informative post. I did a search and ordered a five-pound purple-K extinguisher from this company:

Smokesign

They offer free hazmat shipping.

The five-pound unit seemed like a good compromise between a huge ten-pound unit and a marginal 2.5-pound model.

[Winter]

Originally Posted by lucittm

OK, something I know a little bit about.
First, no fire extinguisher does everything well, you have to figure out what the goal is.
Hint: electrical conduction fires "C" are usually not serious if you can remove the power. The exception is if the electrical fire causes another type of fire. Fires that leave an ash "A" are pretty easy to put out and if you are working on a car fire type "A" materials are carpets, seats, and human beings (we used to call them screaming alfa's). The biggies are flammable liquids "B" and flammable metals "D". The liquids are oil and gas, of course. The metal is magnesium. We have engine parts made of magnesium and there is no way to put out a metal fire because they make their own oxygen and they are very hot.

Second, let's concentrate on liquid fires, the ones that destroy our cars. Aqueous Film Forming Foam (AFFF) is the best but very hard to carry around in the car (that was mentioned before). Also, it has a shelf life and you need enough to prevent a re-flash. I have seen a guy step in a puddle of it and the fire erupted when he lifted his boot. Finally, it has no use on electrical fires and almost useless on type "A" fires. The gases: CO2, Halon, and water fog spray work pretty well but you have to get the fire completely out at close range and hope the surfaces are cool otherwise Poof, a re-flash.

Third, what to use? Powder, but not just any powder. Baking soda works in the kitchen but sodium bicarbonate is not very good at removing the oxygen (smothering) it is slightly better than salt. So we want something that smothers the fire, does not conduct electricity, and not as corrosive as some other agents. General purpose dry chemical extinguishers use monoammonium phosphate, nasty stuff. So, use what the Navy uses on their ships, Purple K Powder (PKP) or potassium bicarbonate.

From Wikipedia:
"Purple-K is a dry chemical fire suppression agent used in some dry powder fire extinguishers. It is the most effective dry chemical in fighting class B (flammable liquid) fires, and can be used against some energized electrical equipment fires (USA class C fires). It has about 4–5 times more effective against class B fires than carbon dioxide, and more than twice that of sodium bicarbonate. Some fire extinguishers are capable of operation in temperatures down to −54 °C or up to +49 °C. Dry Chemical Powder works by directly inhibiting the chemical chain reaction which forms one of the four sides of the fire tetrahedron (Heat + Oxygen + Fuel + Chemical Chain Reaction = Fire). To a much smaller degree it also has a smothering effect—excluding oxygen from the fire."

I have a 10lb bottle of PKP in my car (it fits on a Brey-Krause mount). If you ever have an engine fire, you will be glad if I pull up behind you because I have a 20 foot range and 24 seconds of discharge time. You can get PKP extinguishers at places like this:
Amerex 10 lb Purple K Fire Extinguisher
and
Ansul Sentry 10lb. Purple K Fire Extinguisher - Monroe Extinguisher

More expensive that a 2.5 lb can of baking soda, but inexpensive insurance to me.

Mark

I think you've sold me, Mark. Thanks for an excellent post.

[Vincent Hill]

My Bottom Line is it is ALWAYS Better to have any one of these than to have Nothing! Our plan is always turn everything off and spray just enough to put out the fire so if it returns you have something left to put it out again. I have had to fight 2 fires with one being my Motorcycle and had nothing so I used Dirt and a car up the street that I used a little one and put out the fire and then it restarted because the Dummy still had the Ignition on! I was able to put it out again only to see an electrical fire start under his dash and then It was too late.

I did not know that Halon was no longer available!

[glewis80SC]

I have a 2.5 lbs dry chemical in my SC and hope I never have to use it, at work most vehicle fires start out electrical then get into the combustible materials of the car, i have only had a few where fuel was the ignition source, we use water or foam on 95% of the vehicle fires but we always have a dry chemical ext out just in case the fuel does flash etc. I like the idea of the Purple K and will look into those, but like others have said get out of the car asap with the extinguisher, hit the seat of the fire hard if the extinguisher runs out the back away, even if it was electrical once it gets to the flammable materials disconnecting the battery will not put it out.

[kach22i]

Originally Posted by OJEditor

Mark, thanks for a very informative post. I did a search and ordered a five-pound purple-K extinguisher from this company:

Smokesign

They offer free hazmat shipping.

The five-pound unit seemed like a good compromise between a huge ten-pound unit and a marginal 2.5-pound model.

Where and how do you plan to mount it?

Will the unit you describe fit where others show theirs (between the seats)?