What Kind of Fire Extingisher do you have in your Shop

[randyjaco]

Who has Dry Chemical fire extinguishers in their shop?

I learned the hard way that they do not belong in the shop. I am restoring an old 20" Powermatic band saw that must have been used mainly for cutting sheet plastic. I blew out all the saw/plastic dust I saw. There were a couple of drilled holes that needed filling up, so I got out the MIG and started filling holes. All of a sudden I noticed I had a small fire. I wasn't too concerned because I had removed the dust-Right and the saw is is all metal and I had already stripped all the innards out. All of a sudden the shop started filling up with heavy black smoke. I grabbed one of my trusty dry chemical extinguishers and then another. They worked fine but they weren't putting out the fire. I just dumped 15 pounds of dry chemical into the interior of the saw and it is still blazing. So, I grabbed the hose and the water put it out. The fire is out and I am relieved. Now the clean up. I started to sweep up the powder. It is hydrophobic and doesn't dissolve in water. The powder is like the finest talc I have ever encountered. As I start sweeping and the powder starts filling the air. I turned on the exhaust fan and that helped to clear the air. I had to put on a respirator so I could breath. I started to look at the shop. There was powder on every surface of the shop. I sweaped all the powder off the floor. Next I started cleaning my machines. I cleaned the lathe, then the mill. I looked at the lathe and it had a new layer of dust. I am going to be cleaning machines and tables for weeks. The stuff just moves from surface to surface. It is still everywhere even though 14 pounds are sitting in the trash can.

I will never use a dry extinguisher in my shop again. First thing is that it didn't put out the fire, I felt safe because I had several strategically placed through out the shop, and third it left a miserable mess. For now on it is Carbon Dioxide extinguishers for me.

On a side note I did a final inspection of the saw. Plastic does not turn into dust like wood. It forms fibers of various sizes. Those fibers migrated into the column and other not particularly accessible portions of the saw. Needless to say they burn very well. Since the fire I have probably pulled out a bushel basket full of plastic fiber. None of this fiber was noticeable in the logical places. If you cut much plastic with a wood saw, you might want to inspect your saw from time to time and pull all the clinging fibers out of your saw. They won't just blow out with an air hose. They are quire tenacious.

 

[4GSR]

Water hose.

Have a older 5lb ABC extinguisher. Still holding pressure from last repair 13 years ago. Maybe time to get another one.

Get you one of those 5gal wet/dry vacs from Lowes that fit on a bucket. Use the brush attachment. In no time, you'll have all of that dust vaccumed up.

Sorry to hear about your fire, you never know!

 

[burnrider]

A viable option is the coiled garden hose for use under the sink. You would need to install a 'T' for both cold water tap and ball cock outlet to the coiled hose. Water still has limits for use on electrical, or computer drive equipment. CO2 is more spendy as a first line of defense, but worth it.

Currently have the dry chemical, but I plan to replace it with the beer quick freeze extinguisher.

 

[7HC]

Aqueous foam for me. Good for Class A & B .
It's not corrosive like dry powder and doesn't make much mess.

I do keep a dry powder one available in case of an electrical fire in something that I can't cut the power to, but it's very much a weapon of last resort.


M

 

[burnrider]

Fire prevention means good electrical connectors & equipment, a clean shop, flammables in a metal locker etc. The fire extinguisher a last resort. If we have to use one, the prevention program failed

 

[Bill Gruby]

CO2 -- Have one in each corner.

"Billy G"

 

[cg 2005]

I have four 5 pounders, one by each machine and 25lb outside by the foundry. All dry chemical.

 

[burnrider]

CO2 -- Have one in each corner.

"Billy G"

The best option if the shop is sheetrocked with a concrete floor and low Class A combustibles. Only hazard on older extinguishers was some static shock and as always- oxygen displacement.

 

[bmw rider]

The problem you had extinguishing the fire was that for a dry chem to work it needs to be directed into the flame interface - the space between the fuel and the visible flame. That's why the directions call for a sweeping motion at the base of the fire. Dry chem extinguishes not by cooling or smothering the fire, it inhibits the chemical reaction in the flame itself. If you can't get the powder directed into a hidden space, it won't work, if there is enough heat, fuel and O2 available, it can reignite. And yes, its horrible stuff to clean up. The good part is they are usually versatile in being rated for ABC type fires, though some are BC only.

A good plan is to have a couple of extinguishers of different types on hand, a CO2 extinguisher is a good option as its suitable for class BC fires and will not leave nasty messes to clean up. Water is OK for Class A fires only. Figure out what sort of fire is likely to occur in a given location and what sort of hazards there are in dealing with that fire, then choose an extinguisher that suits that need. Sometimes the drychem is still the best choice.

When you chose a spot for the extinguisher, put it near an exit or at least where you will find yourself heading towards the exit. That way you can continue on out if the fire should grow beyond manageable proportions before you get the extinguisher. And of course, practice fire safety first and foremost.

P.S.: I'm a career fire Captain with 23 years full time and 7 years partime experience.

 

[8ntsane]

Lots of great infro here. Good thing you where able to get it put out, with having the whole shop go up in flames. I guess the clean up will take some time, but Im sure Randy will be ready if it ever happens again. Randy, Im glad to hear you didn't get hurt, and only a massive clean up of your shop is in order.