He was still holding an acetylene torch. A co-worker was standing beside him, speaking. The caption read, “You don’t miss much when you strike up, do you?”
Time for a pop quiz: Which of the following causes the most fires?
1. gas cutting torches (either acetylene or propane)
2. electric arc welders (either stick welders or wire feed)
3. hand-held grinders
The answer is No. 3 – hand-held grinders, probably because the operator does not think that the sparks thrown off by a grinder could cause a fire. The welders and torches, on the other hand, produce big, hot flames and molten metal and slag that obviously will set fire to anything it contacts that will burn.
Another cause of fires that no one expected to be a problem are lawn mowers, both the push type, riding type and the overgrown ones called “bush hogs.”
When it starts to get dark before you get done mowing the tall weeds on the perimeter of your estate, notice that when the mower picks up sand and gravel and throws it out at high speed, there are often sparks. If the grass/brush/weeds being mowed down is tinder dry, it does not take much of a spark to start combustion.
The usual scene is for no one to think that what they are doing could be a fire hazard, and after they finish what they are doing, they leave.
Then the tiny spark that settled in a depression full of tinder dry grass or leaves or hay dust smolders until a little puff of a breeze happens along and fans the smolder into a live flame.
The forest service had a rude awakening years back when catalytic converters became required equipment on cars and pickups. Their own vehicles were starting grass fires – sometimes just by driving over dry grass and sometimes when parked in tall, dry grass.
The latter set a few vehicles on fire from the burning grass beneath it. The current new models of diesel trucks have a “re-gen” mode to clean the particulate filter by burning the carbon it had captured. This results in a tailpipe temperature well above combustion temperature for tinder dry grass.
The best procedure for making a cutting, grinding and welding repair is to remove the broken part or machine from the work area into a repair area where the sparks and flames and molten metal cannot reach things that burn.
If that is not possible then the work area should be cleaned of everything that will burn. Depending on the situation and the location, it may be a good idea to water down the area surrounding the repair site for good measure.
At the scene of an automobile accident you will notice that the rescue personnel cutting open a car to remove the occupant will generally have a charged fire hose ready and held by a fireman.
May I entertain the idea that the more tender parts of the body of someone welding a broken machine surrounded by things that burn, deserves just as much protection as does the above-mentioned rescue person? It takes much less time to get someone with a water hose or fire extinguisher to stand by than it does to get the fire department on the scene.
Years back I was welding up a leak in an oil line. I had the new guy on the crew standing fire watch with a live hose as I welded. A gob of molten steel and slag rolled off of the pipe I was welding on and lit beside my foot.
We had watered down the area but there was enough oil in the area that in a few seconds it ignited, and started my pant leg on fire.
I heard the new guy start stuttering, but I had just managed to get a bead of weld going that had stopped the leak and I wanted to keep welding before I stopped.
The stuttering and stammering got louder in the five or six seconds I continued to weld. When I stopped and raise my welding hood I noticed about six inches of flames starting up my pant leg. I told the new guy to squirt water on it. He did. He had been afraid to squirt water on the boss’ foot. I told him that I would rather have a wet foot than a fried leg any day.
One of the standard procedures we maintain is that when any welding or grinding has been done just at quitting time, that someone comes back at least once and makes sure that there are no smolder fires going.
If you cannot move it out to fix it, then clean around the repair area and wet it down really good before welding, cutting or grinding. Have one or two or a dozen people standing fire watch so there is someone to notice where that red hot little ball of steel rolled to, and can put water on it before it starts the place on fire.
At the repair shop portion of a hay processing plant, I observed everyone looking for the source of the smell of burning hay for three days. When finally discovered, it was a smolder fire moving along a steel beam.
The hay dust was about 1/8-inch thick and the beam was about 4 inches wide. The smolder fire was moving about one foot a day. About three days before the source of the smoky smell was found one of the fellows using the shop was remembered as “having been really wild with a hand-held grinder, throwing sparks all over the place.”
Just as a note of interest, the Moses Lake, Washington, newspaper had on its front page on August 31 a bright orange picture and the headline, “MOSES LAKE HAY BUSINESS BURNS.”
A number of hay compressing and packaging machines along with an unknown quantity of hay inside a four-story-high concrete building burned. And will probably take several days to burn itself out. The cause of the fire is unknown.
Just a few weeks ago our neighboring community of Mattawa, Washington, had a house fire that took the lives of a young mother and two of her children. The cause seemed to be a faulty extension cord.
A true incident from years ago was related to me. “I dozed off while cooking, my nap interrupted by a cat I hated standing on top of me yowling. The pan on the stove had boiled dry and had filled the house with smoke. I appreciated the cat’s warning, but I still don’t like it.”
Last winter a house in a neighboring community burned down two days after a propane torch was used to thaw frozen water pipes.
A crew went to lunch and returned to find the baler they had been welding on in flames. Had they taken a leisurely lunch the shop would also have been on fire.
A young teenager removed the spark plug from a lawn mower to see if it was sparking. With the plug grounded to the body of the mower, the starter cord was pulled.
The reason the mower would not start was that it was badly flooded. When the motor turned over, raw gasoline gushed out of the spark plug hole in the engine head and covered the spark plug lying on the deck of the machine. The spark plug had good spark. It was a hectic few moments to get the garden hose turned on to put out the fire.
Exhaust stacks on hay trucks will set hay on fire. Ask me how I know. Cigarette butts thrown out the window will do the same. Years back we stopped to help deal with a truckload of hay on fire.
It started half-way down the load, level with the driver’s window. After we helped get the half of the load that was burning moved from the truck onto the side of the road, we advised the driver to get rid of anything in the truck cab to indicate that he had been smoking.
It is so simple. Any time you drop something that is burning on something that will burn, you are going to have a fire. Electric wires that are shorted out constitute something that is burning.
An electrical spark will ignite liquid fuel, propane, dust and fuel vapors. A continued electrical spark will ignite whatever it is sparking upon.
It takes less time and trouble to fix it or take it out of service, wet it down or move it, and at least come back in a little while and check on it, than it does to explain why it burned and deal with the mess.
On the topic of fire safety, a little paranoia is a good thing. FG
Brad Nelson
bnelson@smwireless.net
