Almost Started a Fire

By billvanderhoof (****)

Date 03-10-2006 07:33

Fine steel wool is often used as fire starting tinder.
Bill

By yorkiepap (***)

Date 03-12-2006 15:57

Hey LM,
I had a similar incident with grinding sparks on my workbench. After several months of grinding in my vise, the grinder stopped and a large flame shot out of the receptacle over the workbench frying the plug and receptacle. Luckily, like you, I sprayed it with a water spray bottle and snuffed it before any damage could occur inside the wall. When removing the receptacle a lot of metal dust and particles were burned like ash inside the receptacle box. Now I keep all the receptacles over the workbench covered with a laminated rubber flap and the plugs go under the flap into the receptacle. Solved my problem......a good point for others to heed......Denny

By texredneck (**)

Date 03-12-2006 17:31

y'all need to remember water fine on combustables like wood and paper...but you need a " C" category fire extinguisher for electrical stuff. Liquid fires water makes a major mess of. Electrical current can travel back up the water stream. A=ash for wood and paper, B=boil for liquids, and C=current for electrical and ABC fire extinguisher is good in the common shop. An ABCD covers combustable metals like mag.
CHRIS

By yorkiepap (***)

Date 03-13-2006 01:13

You're correct Chris. I failed to mention that the shorted connection tripped the circuit breaker and shut down all the receptacles. And I do have an ABC fire extinguisher on the wall.....Denny

By bzzzzzzzzzz (**)

Date 03-13-2006 02:54

When I took a smaw course at our local community college the instructor had one of the welder outlets do this. They are large amp 208 single phase. A guy was welding in a booth and the welder was acting wonky. Takes off his helmet and sees the wall arc welding itself without an operator. The dust had accumulated on the wall near the recep. and finally found its way to the ground. Burning just like a huge fuse.

By whiteyford M1A1 (**)

Date 03-13-2006 12:32

Howdy
We had a safety demonstration from Harris once. They rolled up a little steel wool, placed it in a 1/4 copper tube about a foot long with one end crimped most of the way closed. The other end fitted to an 02 tank then cracked trhe valve for a second, walaa a steel BB.
Thanks Randy

By Dr. D

Date 03-15-2006 13:10

Am I missing something? Did it turn into a BB just because of the 2000 psi of pressure funneling it
or because of the high rate of oxidation of the steel causing a chemical reaction to make the steel hot enough to melt together into a BB
was there a spark or flame involved
???

By whiteyford M1A1 (**)

Date 03-16-2006 11:54

Hi Dr D
I believe the missing ingredient is the fine amount of oil that is on steel wool. Correct me if I'm wrong but I believe Oil + o2 under the right conditions will spontaineously combust.
Thanks Randy

By aevald

Date 03-16-2006 17:25

Hello Dr D, it might go something like this, in a diesel engine combustion occurs when "air" is compressed to approx. 250 to 270psi. and fuel is injected at the correct time under pressure thus causing combustion and ignition. When steel wool, processing oils, spider webs, anything really is subjected to the extreme pressure of a pure oxygen atmosphere, combustion and heat will also occur. There was a representative from Pacific Airgas in our area who used to do a very informative and enlightning presentation regarding oxy-fuel safety and application, one of his stories regarding equipment safety described a heavy equipment field technician who was working on a job in the field and ran out of oxygen on his truck, he proceeded to unhook the gauge from the tank and set the regulator down in the bed of the truck, he then made a trip back into town and got a new oxygen tank, without paying attention to the regulator before reconnecting it, he hooked it back up and turned the tank on. There was an immediate explosion that blew up the gauge and burned his hand and wrist. When this was investigated to determine the cause it was decided that when he put the gauge in the bed there were oils and greases that got onto the inlet fitting of the gauge, he didn't clean these off before reconnecting the gauge so when the high pressure oxygen was applied it caused ignition and explosion. If you were already aware of this type of condition forgive me for bringing it forward, I mainly did so for those who might be reading this thread and who are not aware of this type of thing. Combustion was explained to me in this manner, the triangle of fire requires a fuel, oxygen, and the material to be brought up to the kindling point(this temperature will vary greatly depending on the type of material), any material will burn in the presence of pure oxygen if the kindling point has been reached, in all of the examples in my post the kindling point was reached due to the pressure involved. Regards, aevald

By Dr. D

Date 03-17-2006 10:42

Thanks Randy & Aevald,
I was aware that when something oxidizes, heat is produced, and the amount of energy created by this process will be the same regardless if it takes 20 years or 2 seconds to completely oxidize.
I coudn't see it being the pressure alone, since for one, wouldn't the same kind of thing be happening inside that O2 bottle every time it is filled, chromoly rusts too(that would be scary) and also because I would have thought the steel wool would be blown out long before the compression ever actually reached 2000 PSI.
But I hadn't really thought about some oil or rust-preventative being on the steel wool that could provide a lower kindling point to start the reaction off easier. Good point. Thanks for helping me to get around a mental block.
By the way Aevald, I've seen some of your other posts and like your responses, you strike me as a guy who has years of knowledge and experience behind him.

By aevald

Date 03-17-2006 15:40

Hello DrD, thanks for the words of confidence. I do have a few years, but I like to credit the many people that I have had the pleasure of being associated with over those years and I guess being able to remember a lot of things that were of importance are a help many times too. The forum has been a terrific source of technical information and the attitudes and logic of it's many users are a constant aid, even some of the negative ones can help to give perspective. Regards, aevald One small footnote: how quickly the enclosed space goes from 0 to pressure and to what degree of pressure it reaches is pretty much the determining factor for the amount of heat created, this is one of two reasons why when you open the valve on the oxygen cylinder or any other high-pressure cylinder, they tell you to do it slowly. The pressure hitting the seat,diaphram,spring assembly too quickly will prevent it from doing it's job properly and allow the gas to bypass it and possibly blow the diaphram out or rupture the pressure gauges. In the case of the oxygen being opened too quickly this condition can happen and also be compounded by the heat being generated and the possibility of combustion.