A small fire (protective screens?)

--My small fire was a few months back *after* I'd done some small part cleaning using solvent (I think it was paint thinner) in a Cool Whip container. Put the lid back on, but left it on one end of the workbench, then proceeded to do some plasma cutting at the other end. Sure enough a spark shot across the bench, burned *through* the container, causing it to spill across the bench, on fire, etc. Grabbe a fire extinguisher not 2ft from me and it was EMPTY!!. Knew the location of another one, ran to get it, put out the fire. Very scary finding that empty fire extinguisher. I've now tested every one in my house/shop and have *doubled* the number of them. Finally got busy and mounted the little plastic hangers that nobody ever uses, so the fire extinguishers don't get shoved in a closet, too.

"Andrew H. Wakefield" wrote: (clip) Thoughts? Improvements? Suggestions (clip) ^^^^^^^^^^^^^^^^^ When you finish any work which could potentially result in a fire (welding, cutting, grinding, etc) stay in your shop for a while--don't just turn off the lights and go to bed.

First thought is to be aware of what you are doing. O/A cutting is really nasty. MIG welding has some sparks, stick welding has more. Grinding aims a long trail of sparks, cutoff wheel has a sharply defined trail of sparks. Think before using any of these, aim the debrie trail in a safe direction. My race car crew get really stupid sometimes, someone will aim a steam of grinding crud at someone else who is setting up to weld. A lot of LOUD yelling usually ensues. But at least someone notices.

Setting up some 4'x8' protctive screens is centainly better than nothing. But they do get quite cumbersome. Suggestion: stretch some 1/8" steel cables (garage door supplies) about 7' off the floor across the area you want to block off. Get some of the cheap blue tarps, add some extra gromets, and hang them from the cables(shower curtain style). Important thing is to get the tarps about 2" off the floor. To keep the sparks from rolling around, you need to have a board OUTSIDE the tarp area. A 2"x4" should do the job nicely.

As someone else noted: several fire extinguishers are a GOOD thing. I have 2 10-BC rated and one 20-BC rated extinguishers in my garage where I do the welding. Basement shop with the wood tools (and sawdust!) has another 20-BC plus a 5 gallon water plus a garden hose with nozzle. I've never had to use any of them.

Try not to work al> Very small. Hardly a fire at all. Just a crumpled up paper towel smoldering

My small fire: I was grinding with a cotton duck apron (my daughter made it as a birthday present). Noticed a little smoke coming from my midsection. Oops, I burnt a 1cm hole in it. Took it off and put it on the workbench--I'll take it over to my daughter's place and she'll patch it. About 30 min later, I glanced over at the bench and saw a ton (metric) of smoke coming from the piled up apron. On picking it up, I saw the hole was now large enough for a circus lion to jump through. There were no flames, it just smouldered up to that size. I got my understanding daughter to make another. I found a leather apron in a yard sale and now use that when I do a lot of grinding.

I do shudder to think what might have occured had I just pitched the apron onto the work bench and then closed up my shop for the day. Yikes. For that reason, I often just quit the shop and go back 30 or 45 minutes or so later to lock it up after a check-up for smoke.

Best, David Todtman

I segregate the workshops. Woodwork happens at my place, metalwork happens at a friend's - we've re-arranged much of the tooling between the sheds. I don't use fire, his damp underground shed doesn't have anything in it that will burn.

Given the inch layer of sawdust everywhere in my place, there's no way I'd weld or grind metal in it.

I did have a small fire a while ago, but it was only a _little_ titanium fire. I was oxy-cutting some fresh scrap (jet engine parts) and I found that the stainless steel also had some Ti bits in it.

Thanks to many of you for sharing your own "small fire" stories -- I'm not sure whether I feel relieved that I'm not the only one, or even more anxious about the potential dangers! -- and for some good suggestions as well.

I fully concur with the several persons who urge not simply closing up shop after welding/grinding, but giving time to discover if anything is amiss. Even before the fire, I have been somewhat paranoid along these lines, going back multiple times over several hours to check to be sure I can't smell anything burning, etc.

I also concur with the advice to keep woodworking and metalworking segregated. Unfortunately I don't have two different buildings to work with, but I do keep the spaces somewhat segregated, and I am very careful to keep all sawdust swept up in general, and especially before doing any metal work. One of these days I would like to build a shop building out back, with the metalworking part constructed of concrete block ... one of these days.

Obviously I didn't follow the advice about thinking about where the sparks would be going, this particular time. In general I do try to do that -- really, I do! -- but sometimes one gets caught up in the moment of rounding over that corner and not bothering to change the position of the piece in the vice ...

Roy, I wanted to inquire further about the idea that you suggested below:

I had thought about using tarps; certainly this would be a quicker and easier solution, and as you say less cumbersome. But I thought a tarp (especially the cheap blue ones) might be too easily melted or ignited by the sparks. Yes? No?

I had thought about needing to leave a little space at the bottom so that sparks can't rest up against the bottom of the screen, whether wood or tarp. Your idea about the 2x4 outside the screen is helpful.

Again, thanks to all, and I look forward to any further suggestions!

Andy

This has been discussed before, but it bears repeating: Do not wear any clothing with frayed edges. A hot dingle-berry can start a smoulder that soon turns into a flame.

Using the blue tarps is expedient but perhaps not the best approach. They will melt if you drop hot slag or hot torch on them. they will also burn through if you aim a concentrated blast of sparks at them ie don't set up your abrasive cutter and aim the sparks at the plastic! But they do stop the occasional sparks and grinder spray. Better is to go to a canvas and awning place and get a fire resistant treated canvas tarp. But much more money than the plastic.

For home use, I'd set things up with the blue tarps and get your procedures and distances correct, then replace them with the canvas.

If you are working in a garage, your only real choice is to make the the door end your metalworking end. This is the only way to get the welding fumes and abrasive cutoff saw near the outside. Set up a curtain to go completely across, set a bead stopper board up, and allow NOTHING on the floor and nothing combustable in that area of the garage. You can run a support cable across under the garage door, pull the curtain into place as required. You might need only about 7' or 8' from the door for the weld area. Leave the door open or open it after welding to let the fumes out.

I typically do my weld> Thanks to many of you for sharing your own "small fire" stories -- I'm not

I'm not too bothered about my clothing smouldering. I never wear synthetics, so a bit of charring cotton or linen is no big deal. I expect to set fire to myself on a regular basis, so I just don't wear something that I can't put out by slapping it with a bare hand. The easy lightability of frays is a good point though.

There's a similar point with woodwork (I also do timber framing). Sharp edges should be chamfered, to make them harder to light. There are legal requirements in odd places like The Factories Act specifying this as a fireproofing measure for warehouses.

One of the weirder fire hazards I worry about is linseed oil on rags (either wood or metal finishing). This is a "drying" oil, meaning it has a drier added to make it cure into a polymerised surface. This polymerisation is exothermic and although it won't set fire to an oiled surface, a finish rag is entirely capable of spontaneously combusting if you just wad it up and throw it down. Mine go in a steel bucket with water in it.

And one you will take note of once you have set yourself on fire a couple of times. It is amazing how quickly they get going, and how hot they get. Tell your story again once you've done it.

It goes something like this:

You're under a hood welding.

Sniff?

What's burning?

OH, SHIT, IT'S ME!

SLAP! SLAP! SLAP! SLAP! SLAP! SLAP!

"Andy Dingley" wrote This

When working with ammonium perchlorate, it will combust if just thrown down.

Steve

I think it is an oxidizer in solid form that needs external ignition. It was the stuff that blew up a rocket fuel plant in NM. a while ago. I saw something on Discovery or some other show if memory serves me correct. (?) I could look it up but I'm too busy watching TV.

My friend summed it up best- as we get older we don't lose our memory, our "forgetters" just get better.

Rob

Fraser Competition Engines Chicago, IL.

The rocket fuel plant was in Henderson, Nevada, named Pepcon. It was about five miles from my house.

I did work at Kerr-McGee in Henderson, another manufacturer and supplier of ammonium perchlorate to the space industry. Before being allowed on their property, you must have a one day safety training course.

Ammonium perchlorate does not need an outside ignition source. If you have some on your pants, and slide over a seat cover, it combusts like a kitchen match. Any friction or concussion can set it off. In one of the films, they toss a pair of boots on the floor that have dried percholorate on them and they burst into flames. Once ignited, it has to burn itself out, as it is almost impossible to extinguish.

The Pepcon explosion killed one man, injured hundreds, did millions in property damage. The thing hardly anyone knows is that at the time, ten times the quantity of perchlorate was sitting on the ground at the Kerr-McGee facility, and that is just across the street from the older section of Henderson, and very near the downtown section.

Since this, Kerr-McGee still manufacturers there, but transports it immediately to their facility at Apex, outside the Las Vegas valley. Pepcon has relocated to Cedar City, Utah.

Steve

And don't weld or cut while sitting in a chair without an apron..... If you have to use a chair, sit on the edge. I think we can all figure how I relearned that the hard way. Healing sucked as bad as that rapidly heating sensation in places highly prized! Smacking at it doesn't feel good either.

Yeah, synthetics or blends are definitely a no no. I found out one of my t shirts was a blend after I took it out of the wash and I could see lots of daylight through it. I got lucky that the shirt stopped everything.... Many years ago I was welding on a short piece of pipe with a torch and noticed a warm sensation on my arm. My cotton shirt sleeve had burned away and the hair on my arm was going next. If it were a blend I'd still have bits in my skin. There was an unburned mix that went out the hole in the tube and relit.

My garage is so crowded that I do my welding outside, which the idiot I was that I didn't make the replacement power cord on my welder long enough! My vise got moved away from the parts washer, too.

Yes, but you'd _expect_ that sort of malarkey from a perchlorate !

More like "Oh dear, here we go _again_"

If I'm really going to set fire to myself at an annoying rate (usually when cutting), I wear the leather jacket - sometimes even the leather nun's wimple, or the posh Formula 1 one if it's hot weather. In winter my usual overalls are an aircraft flightsuit, which is ignition proof too. I'm not a grease monkey, so my kit just isn't all that flammable. I keep my hair cut fairly short too.

I did once have an eyebrow fire. As my eyebrows can attract the Evil Eye and curses of "werewolf", that's a bit serious.

I don't know that I've had a true "eyebrow fire", but I've burned them (and my eyelashes) off. I've had my hair on fire- it's amazing how much heat is released by hair burning..

You're right about the synthetic stuff- it's evil. I don't let the kids wear it, it's just evil.

There was a little girl in the town near my house, had a nylon nighty on and leaned over a lit candle. The family had a lot of trouble catching her, finally got her in the snow outside.. last I heard the doctors weren't sure if she was going to live or not, I never looked into it further, didn't really want to hear the end.. Bad stuff, I hate it.

John