Fire! Fire!

[Bob Keyes]

Well, after a lot of engraving and cutting over the last 24 months I had my first fire tonight. I was cutting some 1/2" acrylic and was busy with something else at my bench adjacent to the engraver.



I heard a muffled pop and when I turned to look the inside of the engraver was aflame. I just turned off the laser beam and let the machine run. Then I grabbed my trusty, new I might add, First Alert Tundra fire extinguisher, opened the lid and sprayed the fire out. There was a brief secondary flare up which the Tundra took care of easily.


Dirty mirrors, dirty lens, warped top window, but no other damage. The cleanup was easy once everything cooled down. A paper towel or 3 and some Windex and it was over.



Two things here. I was right there with the machine. If I had not been it would have probably burned down my house.


Second, I had a fire extinguisher right there within reach. There is really no excuse for not having one. First Alert has these now for less than $20.00. If I had not had one I'm not sure what would have happened, but I am sure it would have cost me a whole lot more.


Heed the warning. I did and I'm sure glad. Go get the Tundra if you don't have an extinguisher already.


(Standard disclaimer. I don't work for nor have any affiliation with First Alert. They just make an effective, affordable fire extinguisher.)

[Ken Fitzgerald]

Bob...I don't do lasers....but I do wood working. I will be buying a fire extinguisher and it will be mounted on the wall next to the walk thru door!

Thanks for posting!

[Craig Hogarth]

Given a choice between burning down the house or using the tundra, I'd use the tundra. But dry chem extinguishers can destroy electronics beyond repair and a co2 is a much better option.

[Mike Hood]

... and most fire extinguisher stores have used CO2 bottles you can get very inexpensively. I have a 30 pounder sitting next to mine and if that's not enough to stop a fire, it's time for 911.

CO2 won't hurt electronics or foul your optics like an abrasive dry chemical would.

[pete hagan]

Bob, sorry to hear of your fire. I just scolded a 20 something for "goin to lunch" while cutting a sheet of 3/16 acrylic last week. I have printed your post and pasted it to his time card!

I'm buying a CO2 extinguisher first thing Monday. We've got several dry chems on the walls but I definately do not want to be cleaning the laser inerds from it.

Let me know if you need any assistance up here in horse country.

Pete

[Gary Hair]

Forget dry chem and co2, you really want a halon extinguisher. They are about 5x as much as the others but you won't ruin your machine. I have two small ones I bought a few years ago and always have them within reach.

Gary

[Bob Keyes]

Here's what I know about fire extinguishers. Halon would be the best. Very expensive, cannot be made in the US anymore, supply will slowly run out. CO2, fairly expensive. Need training to operate. Has to be refilled if used only once. Clean up is non existent and it won't hurt electronics although the potential is there since the ice it forms is electrically conductive. Dry chemical is bad. Effective fire suppressant but the clean up is really nasty.

The new Tundra is a liquid. Very quick, I found out, at snuffing out the flames. It comes in a can like spray paint and is used until it is gone. Then you throw it away. The clean up was easy as stated before. It is dirt cheap. I went on line and bought 4 of them for under $60.00.

Whatever you decide, GET SOMETHING!! NOW!

[AL Ursich]

I have 2 fifteen pound CO2 bottles plus a few dry chemical and I see this as my first choice. Been around a few fires in my Navy days and have an appreciation for CO2.

A bag inside the can is pressurized and only fluid comes out of the can, not a bad design. No flammable gas...... Couldn't find anything as to weather it can stand freezing in a unheated shop? The Laser Shop is heated but the Wood Shop is not yet.

Thanks for the tip, I had not seen them before. Haylon is good but bad for the earth.....

AL

[Mike Hood]

I don't know where you guys keep getting this "dry ice is conductive" and therefore dangerous around electronics. That's just not true.

CO2 (in gaseous, liquid, or solid form) is non-conductive, non-toxic, chemically inert, and non-abrasive. I wouldn't think twice about using it on my laser. It's inexpensive and can deliver a steady stream of fire extinguishing agent to the laser and the exhaust system.

Get a 20# bottle and keep it handy. If you use it, you only need to get it refilled and it's incredibly inexpensive to top one off.

[AL Ursich]

I believe from my Navy Fire Training days that it is the water vapor in the air that forms the ice on the outside of the horn that is conductive. Water Vapor ice not dry ice.

Carbon Dioxide (CO2) extinguishers are most effective on Class B and C (liquids and electrical) fires. Since the gas disperses quickly, these extinguishers are only effective from 3 to 8 feet. The carbon dioxide is stored as a compressed liquid in the extinguisher; as it expands, it cools the surrounding air. The cooling will often cause ice to form around the “horn” where the gas is expelled from the extinguisher. Since the fire could re-ignite, continue to apply the agent even after the fire appears to be out.

I have also seen guys get a nasty static electricity shocks from holding the bottle while discharging it. They recommend setting it on the ground while discharging it. Only happens under very dry conditions and sometimes standing on a steel deck.

AL

USN Retired

[Craig Hogarth]

I don't know where you guys keep getting this "dry ice is conductive" and therefore dangerous around electronics. That's just not true.

I think everyone is talking about condensation and freezing from the expended CO2.

But with any electrical fire, the first thing that needs to be done is to shut off power, preferably at the source. This will reduce the chances of reflash and no amount of water will damage the equipment.

[AL Ursich]

NORFOLK, Va. - A small fire broke out aboard a Navy guided missile cruiser Saturday, injuring five civilian workers, officials said.
The workers were taken to Sentara Norfolk General Hospital. The extent of their injuries was not immediately known.
The USS Leyte Gulf was undergoing repairs and a renovation when the fire started Saturday morning, Norfolk Fire and Rescue Battalion Chief Bruce Evans said. The blaze was put out by a portable extinguisher about 15 minutes after it began.
The fire was caused by an accidental build up of lacquer thinner fumes, Evans said. The source of the ignition was not determined, he said.


The ship, a Ticonderoga-class cruiser, was docked at BAE Systems Ship Repair Systems. The fire occurred two decks below the main deck, Evans said. No Navy personnel were injured, he said.
A message left by The Associated Press at Naval Station Norfolk was not returned.
The 567-foot warship carries two SH-60 Sea Hawk helicopters and its armaments include Tomahawk missiles, torpedoes and Harpoon missile launchers.
Leyte Gulf is based in Norfolk and carries a crew of more than 380 officers and enlisted personnel.

[Joni Campbell]

Oh No I am glad you got it put out before you had any real damage. I'm off to get a CO2 just to be safe

[Darren Null]

Obvious, I know, but in an emergency you're not always thinking about anything but the fire. Power off first, yes.

Also with CO2 your hand can freeze to the horn, so pull your sleeve down or wrap something round it first...you don't always have time to thaw naturally and you can rip a fair amount of skin off if you're in a hurry.

Also, consider ventilation. CO2 and Halon work by starving the fire of oxygen; and it can have the same effect on you if you're not careful/in a poorly ventilated or enclosed space/are very enthusiastic putting the fire out.

I have a large CO2 extinguisher and a small Halon one (illegal in the UK, but I'd like to see somebody prove that there's an inert gas in all that smoke I'm letting out the window).

EDIT: I'm also glad that you got off with no damage Bob. Good one.

[Mike Hood]

The thing about CO2 is you can dispense a much larger amount of agent at a much lower cost. A used CO2 unit can be picked up very inexpensively and a 20 lb unit will put out a HUGE fire if used properly.

You can always regulate the amount of CO2 you're dispensing and once the cabinet is full of CO2... nothings gonna be burning. Same goes for you exhaust system.