ABC Fire extinguisher "corrosive problem" with aluminum

[Vovchandr]

Element got back to me

 

"Thank you for taking the time to contact us. The extinguishing agent your friend is referring to is Halon/Halotron which is considered to be a 100% clean extinguishing agent. In an aviation setting, an ABC extinguisher should indeed be avoided since it produces a highly corrosive powder that is almost impossible to remove entirely, is very damaging to metal alloys and electronics, and which can cause terminal damage if it gets into an engine.

 

 

 

We are European vintage car guys here and one of the main reasons we got involved with this product is because we wanted an alternative to the ABC extinguishers that are commonly in use in the classic car world. The majority of fires that can be tackled by a car owner are small and an ABC extinguisher, most of the time, ends up doing much more damage than the fire itself. Our extinguisher utilizes a ‘clean’ extinguishing chemistry that leaves virtually no secondary residue. A light blast with compressed air is normally sufficient to remove anything that remains after a fire is out. Hope this addresses your concerns."

 

Good info 

[Timothy Keith-Lucas]

Former University Fire Marshal and fire extinguisher tech here.  Let's look at it from a practical side.

 

First, what's the fire likely to be? The scary possibility is that it's Class B, meaning gasoline, since a gasoline fire in a car can kill the occupant(s) very quickly. The second possibility is that it's Class A (Polyester resin and tires, in this case) because we are talking about Sevens. The resin burns very quickly, the smoke is very toxic, and the car is destroyed very quickly.  We don't want that to happen. Class C is only a concern in the fire originating in the electrical system, at 12V DC, so using water is OK.

 

Dry chemical is cheap and the extinguisher not very heavy. It does a good job on Class B (oil and gasoline) fires, and a fair but not very good job on A. It makes a horrid mess and destroys anything electronic it touches, due to its corrosive properties. It makes a crust between the fuel and the flames, and does little to remove heat.

 

Halon derivatives are very expensive and act by displacement of oxygen. It does little to remove heat from a Class A fire, and in an outdoor environment (race day) can blow away. It is very clean, destroying nothing.

 

CO2 is cheap, displaces like Halon, does not remove heat, is clean, and blows away.  Its containers are very heavy.

 

Water (Yes, they make water extinguishers) is cheap, heavy, does a great job cooling a Class A fire, but is useless in a Class B fire.

 

So, what's the practical solution for a Seven on fire with fuel and fiberglass likely involved? At that moment, dry chemical is the best compromise. IT makes a whopping cloud of powder, It will stop both Class A and B, and if we have water (or foam) coming soon the water can cool everything down below flash point. Then we have one hell of a mess, and the electronics (on a Seven?) are shot, but we got the most possible property protected and the best opportunity for getting the occupants out. Particularly on a windy day, we could not have done as well with Halon, CO2, or water.

 

The next day, you go at it with lots of soapy water. It's corrosive, and even mild corrosion bothers the airlines, but it's not THAT corrosive.

[Vovchandr]

1 hour ago, Timothy Keith-Lucas said:

Former University Fire Marshal and fire extinguisher tech here.  Let's look at it from a practical side.

 

First, what's the fire likely to be? The scary possibility is that it's Class B, meaning gasoline, since a gasoline fire in a car can kill the occupant(s) very quickly. The second possibility is that it's Class A (Polyester resin and tires, in this case) because we are talking about Sevens. The resin burns very quickly, the smoke is very toxic, and the car is destroyed very quickly.  We don't want that to happen. Class C is only a concern in the fire originating in the electrical system, at 12V DC, so using water is OK.

 

Dry chemical is cheap and the extinguisher not very heavy. It does a good job on Class B (oil and gasoline) fires, and a fair but not very good job on A. It makes a horrid mess and destroys anything electronic it touches, due to its corrosive properties. It makes a crust between the fuel and the flames, and does little to remove heat.

 

Halon derivatives are very expensive and act by displacement of oxygen. It does little to remove heat from a Class A fire, and in an outdoor environment (race day) can blow away. It is very clean, destroying nothing.

 

CO2 is cheap, displaces like Halon, does not remove heat, is clean, and blows away.  Its containers are very heavy.

 

Water (Yes, they make water extinguishers) is cheap, heavy, does a great job cooling a Class A fire, but is useless in a Class B fire.

 

So, what's the practical solution for a Seven on fire with fuel and fiberglass likely involved? At that moment, dry chemical is the best compromise. IT makes a whopping cloud of powder, It will stop both Class A and B, and if we have water (or foam) coming soon the water can cool everything down below flash point. Then we have one hell of a mess, and the electronics (on a Seven?) are shot, but we got the most possible property protected and the best opportunity for getting the occupants out. Particularly on a windy day, we could not have done as well with Halon, CO2, or water.

 

The next day, you go at it with lots of soapy water. It's corrosive, and even mild corrosion bothers the airlines, but it's not THAT corrosive.

 

Very good breakdown and useful info. 

 

What's your opinion on Element extinguishers?

 

First Alert Fesa5 isn't "A" rated I assume?

[jbcollier]

Halon (and derivatives) does not work by simply displacing oxygen.  It interferes with the combustion process itself.  It's very effective.

 

With any gas based system, you need to stop first before firing the system.

[panamericano]

8 hours ago, Timothy Keith-Lucas said:

Former University Fire Marshal and fire extinguisher tech here.  Let's look at it from a practical side.

 

First, what's the fire likely to be? The scary possibility is that it's Class B, meaning gasoline, since a gasoline fire in a car can kill the occupant(s) very quickly. The second possibility is that it's Class A (Polyester resin and tires, in this case) because we are talking about Sevens. The resin burns very quickly, the smoke is very toxic, and the car is destroyed very quickly.  We don't want that to happen. Class C is only a concern in the fire originating in the electrical system, at 12V DC, so using water is OK...

Agree.  Our most likely fire is B (gasoline, etc) or C (electric) as stated.  "A" would be small to start with, we are not an 18 wheeler with a tire fire.  Anyway, water is the best thing for A, even if it's a ditch of water.  C is usually going to be preceded by the smell or something not working, or smoke getting out of the wires.  That's what the ignition switch or master battery disconnect are for, and the dry chemical BC if needed.  B is the only one that really scares me and the BC is fine for that.  If the one on the car is not enough, hopefully help arrives with another.  Been on both ends of that.  (IMHO, US DOT & WSO Safety & Security Director, ret.)

 

[MV8]

This all assumes we are capable of reaching and operating an on-board extinguisher after something bad happens. Engineering and condition are more important. Steel fuel and brake lines, minimal rubber hose of the right type in good condition, routing hoses away from exhaust, tank venting with a check valve away from a potential vapor collection point under the car, and electric pump auto shutoff from inertia, minimum oil pressure, or minimum engine air flow should be part of the plan. None of these things cost very much to do yourself in upgrading an early cat and most are essentially invisible. I'd feel safer on a track with people paying attention. I wouldn't assume anybody is coming to help on the road.