View Full Version : Fire extinguisher for the shop
02-06-2008, 03:35 PM
Someone mentioned fire extinguishers in the tumbler thread. Which caused me to remember that a recent visitor to my shop mentioned there's extinguishers available that are intended to deal with chip fires.
So what kind would that be? CO2?
I do keep a couple dry-chemical type extinguishers in my shop, but I'd hate to need one and find I didn't have the right one...
This link http://www.hanford.gov/fire/safety/extingrs.htm#feratings explains fire extinguisher ratings.
A = ordinary combustibles
B = flammable liquids
C = electrical
D = flammable metals, often specific to a particular metal
If you're worried about a Class D fire, then you'll need to get a specific Class D extinguisher. Otherwise, a typical ABC extinguisher ought to suffice. But a CO2 extinguisher would be a lot less mess! I don't think CO2 is best for Class A fires though. Probably somebody else knows a lot more about it than I do and can give more detailed recommendations.
02-06-2008, 04:50 PM
A quick search on Halon and I found out that it was banned in the UK for new production as it is harmful to the environment and all the stocks were shipped to the States.
AFIK Halon is the only all purpose fire extinguisher. (still allowed in fighting vehicles)
I have two, NOS and a dry powder.
02-06-2008, 04:50 PM
Forrest points out rather aptly that in a lot of cases, you want to put out a small fire and not destroy everything. Dry chemical can rust everything in the shop. I too have one...but I also have some jugs of water and I would like to find an old water extinguisher.
Some metal fires are accelerated by water....I recall a big magnesium fire at a recycling firm not far from my parents in Anderson, IN. It made the news a year or so ago. The fire chief was asked about use of sand by the reporter who must have done some homework. He pointed out that there was not enough sand in 30 miles to pile on the giant piles of magnesium that were going by that point.
I have a 5lb CO2 in the garage shop as well as a 2 lb dry chem. At the top of the stairs just inside the door from the shop is a 2 gallon pressurized water. In summer just outside the shop doors is an 60 gallon pressurized water. Also in summer is a 100 gallon tank on a trailer with 100 feet of 1" hose and a pump. Downstairs in the indoor shop is a 2 lb halon. In the kitchen is a small foam extinguisher. In the garage shop there is also a 2 gallon bucket of sand. That is approved for metal fires but I don't machine flammable metals. It's too hazardous, especially when you don't have a fire department to call on.
02-06-2008, 05:13 PM
I have 4 (large home sized) ABC chem extinguishers in my shop (38'x40' trussed building), with plans to add a pair of pressurized water units running AFFF (foaming agents).
Halogenated systems are in very limited use now, mostly in environments that will see massive damage from other extinguishing methods (think water or caustic chemicals in a room full of servers or tel-co equipment).
For my shop use ABC will cover the possible range of fires. If I have a fire around my machine tools I'll happily douse them with chemicals and water then worry about cleaning them up later. That said, if I ever run across a deal on a CO2 extinguisher I'd buy it.
One other thing to keep in mind. Halogenated and CO2 systems displace O2, so using a CO2 extinguisher in a small shop will create a very dangerous place for humans to be.
Magnesium and water fun:
A water extinguisher is usually the best bet on a class A fire. Sand will work on a small class D fire, but it better be DRY sand.
Cleaning up the corrosive mess from a dry chem just once will make the expense of a co2 extinguisher seem like very cheap insurance.
02-06-2008, 10:39 PM
From your responses and a bit of Googling it looks like CO2 would be a good investment.
I found an interesting link here on the subject of chip fires:
Seems like good incentive to clean the chip pan regularly!
Paul, I remember that too. Turned out to be arson if I recall correctly.
02-07-2008, 06:16 AM
House or shop, You should have at least a 10 # extinguisher.
02-07-2008, 06:42 AM
CO2 fire extinguishers are NOT suitable for class A fires. A 10lb ABC dry chemical and a 2 1/2 gallon pressurized water makes a good pair for a shop. Caution with the water, electricity and water will kill you.
Class D fire extinguishers are metal specific. Some use salt, some powdered copper among others. If you can be more specific on the metal, I can provide more info.