PDA

View Full Version : ABC fire extinguishers.



Joe Hillmann
02-23-2012, 1:52 PM
It was that time of year again for me to have my fire extinguishers recertified. When the guy was here checking on them I told him about the fire that I had in the lasers recently and how I reached for the extinguisher but didn't use it. He told me that the chemicals in the ABC extinguisher are very very corrosive to aluminum and could cause more damage to the lasers than the fire would. He told me that CO2 would be the way to go.

I just figured I would post this so everyone here would know the risk of using a ABC extinguisher in there lasers (ABC extinguishers are the most common because they are cheap and work on electrical fires, grease fires and wood fires)

Bill Gailey
02-23-2012, 2:09 PM
How did you put the fire out? A few years ago I had a fire in mine from the creosote build up in the exhaust. I grabbed my ABC and used it when there were flames inside the cabinet of my 24x36 machine. It put the fire out quickly. After making sure the fire was out I used my shop vac and then my air compressor to clean everything out of the laser. Pulled off the covers and blew the whole thing out. Had about $1500 worth of damage that was caused by the fire but none from the corrosion. I think if I had left it there waiting for the insurance company adjustor I probably would not have had the same results. I just don't know how you could have put the fire extinguisher down unless you had a CO2 as a backup.

Joe Hillmann
02-23-2012, 2:24 PM
I grabbed the head of the laser and pulled it out of the way (well still running, not a good idea I know) then grabbed a towel and beat the fire out. The reason I didn't use the fire extinguisher is because the fire wasn't out of control at that point and I didn't want to deal with cleaning up whatever came out of the extinguisher. At that point I knew nothing about the corrosiveness of the powder in it. Although even knowing it will cause damage I would still use one if I had an out of control fire. I just put this up here so people who decide to can get prepared in advance of having a fire by getting an extinguisher that will do less damage.

Kim Vellore
02-23-2012, 2:54 PM
A small Halon extinguisher will be most effective with least damage to the lasers from using it.

Kim

Rich Harman
02-23-2012, 3:04 PM
I have a NitroStrike mini foamer (AFFF) extinguisher to use as a first response to fire. It is a water based foam. If that doesn't work then I'll use the dry-chem.

Joe Hillmann
02-23-2012, 3:20 PM
Halon, that was the other one he suggested, I couldn't remember the name of it until you posted it, Kim.

Chuck Stone
02-23-2012, 4:22 PM
they've replaced Halon with something else now .. doesn't work as
good, but Halon is a CFC. CO2 can 'cold shock' electronics, which Halon
won't do. And while it isn't as good as water on common combustibles,
it will still work on class A fires. It is as good as CO2 on class B.

If you can still get a Halon extinguisher, and know where to get it refilled,
then by all means.. get one. It is better than CO2. They stopped making
Halon almost 20 years ago, but there's still over 20 years left in stockpiles
and it can be recycled.

John Noell
02-23-2012, 5:24 PM
Halon is a banned substance and only 'grandfathered' installations are permitted in the USA (don;t know about elsewhere). CO2 is what Epilog recommends.

Neil Pabia
02-23-2012, 5:45 PM
Halon has been replaced by Halonite I believe. Either one was great for putting down a fire quick but Halon would kill you in the process I was told. I do remember that it worked great for cooling down warm beers at the end of a rough day. The CO2 extinguisher will do the job and save you money over the Halonite (and will also cool off the beers).

Duncan Crawford
02-23-2012, 6:08 PM
It was that time of year again for me to have my fire extinguishers recertified. When the guy was here checking on them I told him about the fire that I had in the lasers recently and how I reached for the extinguisher but didn't use it. He told me that the chemicals in the ABC extinguisher are very very corrosive to aluminum and could cause more damage to the lasers than the fire would. He told me that CO2 would be the way to go.

I just figured I would post this so everyone here would know the risk of using a ABC extinguisher in there lasers (ABC extinguishers are the most common because they are cheap and work on electrical fires, grease fires and wood fires)


Joe,

Do a Google search for Halotron extinguishers. That's the replacement for halon-- clean, no cold shock potential like CO2, no Purple-K or other potentially corrosive dry powder to clean out of the optics or exhaust or anywhere else. Not cheap, but a lot less than a new machine.

duncan

Chuck Stone
02-23-2012, 8:07 PM
Halon has been replaced by Halonite I believe. Either one was great for putting down a fire quick but Halon would kill you in the process I was told.

Actually, no .. that was one of the features of Halon.. it WON'T kill you. CO2 can, as it
displaces the available oxygen. In a gas flooded room, CO2 can cause suffocation. Halon
might make you light headed. In very high concentrations it could cause arrhythmia, but
it isn't likely that anyone would have access to that much Halon.. certainly not from
a fire extinguisher (or 10) The most common health risk from Halon is frostbite.

John .. the manufacture of Halon was banned in 1994, but the existing supply can still
be sold and recycled. Extinguishers can be emptied, recycled and refilled. High pressure
tanks can last for decades and kept in service. (but parts are getting harder to find)
Airlines and military still use them because it is one of the most effective fire suppressants
in a closed environment with minimal health risks. So while they can't be manufactured
anymore, you can still buy, sell and use them.

Randy Digby
02-23-2012, 11:04 PM
As I was retiring from the plastics industry in 2007, we were replacing our Halon Bombs with an FM200 agent. Don't remember who makes it but I'm sure Google does. I had maintenance and fire protection responsibility for the largest thermoforming plant in the states under one roof and we used a variety of extinguishing agents, depending on the hazard. Our computer rooms were protected by halon systems backed up by delayed action water sprinkler system. For our major electrical, we would place a CO2 extinguisher (or several) close to large electrical panels and drive systems and then have dry chemical not far away. The CO2 cause less damage but are not rated as effective as dry chemical. First attack was with CO2 to save the equipment, second level was dry chem and 1-1/2" hose lines to save the plant. You would be hard pressed to dump enough CO2 in an office area to inhibit breathing unless you had several 20 lb. bottles. Dry chemical will make you find a door quickly. I've been rendered unconscious from taking a direct shot from a dry chem in the face - not fun. We put close to 2,000 pounds of dry chem on that little fire.

As you decide what to use, be sure to educate yourself with the fire extinguisher rating system. It is a relative system devised to let one compare the effectiveness of one type or size of extinguisher to another based on fire class.

I operate out of our residence and my first defense is a spray bottle of water. Next line is a dry chem.

Dee Gallo
02-23-2012, 11:56 PM
Thanks, Randy. That was a clear and handy overview outlining the best options for me. I'm sure others will find it instructional as well.

cheers, dee

Neil Pabia
02-24-2012, 1:24 PM
Actually, no .. that was one of the features of Halon.. it WON'T kill you. CO2 can, as it
displaces the available oxygen. In a gas flooded room, CO2 can cause suffocation. Halon
might make you light headed. In very high concentrations it could cause arrhythmia, but
it isn't likely that anyone would have access to that much Halon.. certainly not from
a fire extinguisher (or 10) The most common health risk from Halon is frostbite.


Guess I was misinformed, I was told that it sucked all the oxygen out of the room and put down the fire. I really only used it for cooling beers.

AL Ursich
02-24-2012, 1:30 PM
No mention today of the little kitchen fire extinguisher in a spray can..... The kind they are selling for a grease fire. Fluid without the air blast... http://firstalert.com/videos/tundra Saw it for the first time on a Thread here 2 years ago...

AL

Chuck Stone
02-24-2012, 3:34 PM
Guess I was misinformed, I was told that it sucked all the oxygen out of the room and put down the fire.

No, but CO2 does that.



I really only used it for cooling beers.

Well, that is the proper use according to the manual.

Martin Reynolds
02-25-2012, 2:28 AM
We had a laser fire, and I used a dry powder extinguisher. It was the right thing to do, as the thing was flaming.

But the residual powder is a disaster. It is extremely fine, and got all through the laser and the room. It is VERY corrosive. In the laser, it ate slide bearings and exposed electronics. Elsewhere, I got light oxidation of metal surfaces.

So we bought a $100 halon-type extinguisher. One of those things that I wish I had known beforehand!

We still have dry powder - it is wicked quick at stopping a fire. But it is only there for after the halon-style extinguisher is empty.

Chuck Stone
02-26-2012, 10:41 AM
We still have dry powder - it is wicked quick at stopping a fire. But it is only there for after the halon-style extinguisher is empty.

Just an FYI..if there's still fire after discharging the Halon, the extinguisher
is too small. The best use of Halon is a total flooding, meaning the tank is
the size needed to reach the right Halon/air ratio in the room when the tank
is discharged and doors/windows are closed. It isn't really meant for a 'spot
shot' like CO2 or powder. It'll work, but it sounds like you want a bigger tank.

Neil Pabia
02-26-2012, 2:47 PM
No, but CO2 does that.



Well, that is the proper use according to the manual.
I never read the beer manual.

Jerry Bruette
02-26-2012, 3:44 PM
I don't usually hang around the engraving forum but "ABC fire extinguishers" caught my eye.

First thing I'd like to add is that a fire is nothing to take lightly. They can get out of hand very fast wether you have a extinguisher or not.

I work for a company that makes every type of extinguishing agent available. We're not into the "home" market but provide protection for commercial and industrial applications. That said here's a run down of agents and my opinion of what I'd use.

Fire extinguishing agents don't suck the oxygen out of the air, they displace it or prevent it from reaching the fire, which is how the foam agents work. Foam agents can reak havoc with electrical components. They're used mainly on class B fires.

ABC chemical, also known as Foray, is made from MAP which is corrosive and also a good fertilizer.
PKP or purple k is also corrosive.
Halon would be so hard to obtain that it's not practicle to use.
CO2 will work.

For your lasers I would use FE-36, FM-200, or a product called Sapphire. They are all what's known as "clean agents". They won't harm electronics. I've seen a demonstration of Sapphire where a cell phone was submerged and used to make a call when it was pulled out.

Just remember a 911 call before you start to fight a fire may save your shop or home. And you should kill all electrical power to the equipment or the fire may restart when you think it's safe and your extinguisher is empty.

Jerry

Glen Monaghan
02-26-2012, 6:35 PM
I've recently seen something called Halotron extinguishers for sale, is that different than Halon? Is there any legitimate comparison between, for example, a 15# CO2 unit and a 15# Halotron unit?

-Glen

Randy Digby
02-26-2012, 8:08 PM
Look for a rating number on the extinguisher or in the sales literature. The Halotron and CO2 extinguishers are typically rated for class B & C fires. B being liquid fuel fire and C being electrical. There will be a number before the B, and the larger the number, the more fire the extinguisher can handle when used by a person properly trained in using the extinguisher. There will not be a number in front of the C. A C designation merely means that the extinguisher can be safely used and is effective on electrical fires. If you are comparing ABC extinguishers, there will also be a rating number before the A for the extinguishers effectiveness on solid fuel fires. I once had the testing/rating criteria committed to memory, but as the need to know retired - so did the specific fire test sizes. Bottom line - bigger number will put out bigger fire.

Dan Hintz
02-27-2012, 8:21 AM
For your lasers I would use FE-36, FM-200, or a product called Sapphire. They are all what's known as "clean agents". They won't harm electronics. I've seen a demonstration of Sapphire where a cell phone was submerged and used to make a call when it was pulled out.
Not that I disagree with what you've written, Jerry, but your example doesn't sound like a very scientific test. Most electronics would work just fine after being doused in a standard dry chemical agent, too. It's extended exposure that destroys the electronics through corrosion, not instant exposure. It's likely this Sapphire does not corrode with extended exposure, which is good, but I just wanted to point out that spray-and-call doesn't prove that.

Randy Digby
02-27-2012, 10:08 AM
I agree with Dan that quick clean-up after dry chemical use is key. I've seen large DC drive panels (400 HP) where we dumped 10 to 15 pounds of dry chem in them to extinguish a fire start back up within hours after a good clean out with compressed air and vac and then replace the components that had let their smoke escape.