Thread: Preventing and dealing with fires in the workshop

Been pondering the best way forward since I had to put out a fire in the workshop yesterday - caused by welding spatter on an old bedsheet that I had covering a machine.

I know that ideally one should remove all flammable material within X metres of where you are welding - but that's not always possible or practical.
I also know that there's standard "what to do in case of fire" procedures that we all get pounded into our heads at work etc.
In my opinion they are primarily about staff safety and the "raise the alarm, attempt to extinguish the fire if safe to do so, then take steps (BIG ones) to get yourself and everyone else to a good vantage point so you can video the action and put it on YouTube" isn't quite how its going to go down by yourself in a home workshop.
Obviously personal safety is still the biggest concern, but you'll be wanting to have a much more decent crack at the "attempt to extinguish" part.

So other than removal of combustibles - what about things like welding blankets (either fibreglass or leather) to cover them up?
Is there some other material that can be used as a dust cover that won't actually flame if it does happen to cop a few sparks?
Perhaps with the addition of some rigid non-combustible material that can be used as a shield around the welding area?

I was actually quite surprised that the bed sheet went up the way it did.
I'd always thought cotton tended to just smolder rather than flame, but this definitely had flames - about 0.3-0.5m high ones that were enough to warm the back of my neck from a couple of metres away!!
I'm pretty sure it was cotton, but perhaps being very old/thin contributed to it burning quickly.
My welding jacket has a cotton body and leather arms - but the cotton is treated with something to stop it burning. Maybe its possible to get that sort of pre-treated material to use as covers, or treat your own material?

With that all sorted - despite your best efforts towards prevention - you've somehow ended up with a fire.
What is the best way to deal with it and A) put the fire out and B) cause as little secondary damage as possible?
To define the scope a bit more I'm specifically asking about inside the workshop (not outside in the open air), and combustible solids/liquids (ie not electrical or metal fires).

Steve

I have a fire extinguisher in the shed - it's a dinky little thing, but it is there.

How about some of those translucent welding screens and hanging them up between you and the bedsheets? They are made to take welding and while probably will burn, at least it is hanging in mid air and you will see it.
For my machine covers I favour heavier material (canvas etc) as they take a bit more energy to get going.

Michael

I've set myself on fire in my shed several times with an angle grinder and a multi tool linisher. The funniest was when using an angle grinder I set my my flannel shirt armpit on fire and I was wondering why it was so hot. Another time was when sparks from an angle grinder set a waxed buffing wheel alight - actually this has happened several times. One time many moons ago a power point in my shed caught fire because ants set up house inside a double power point (that was in line with the ejecta off my table saw and became covered in sawdust so nice and warm). That power point was under a window and one day it squalled/rained so hard it came in under the window into the power point and started to smoulder the sawdust. This eventually dropped the breaker up in the house but by the time I found the problem the power point and surrounding sawdust had caught fire.

What have I done about it?
I have 3 fires extinguishers, 2 powder, one by each door, plus 1 CO2 foam, plus a fire blanket.
I have a fire alarm that gos off too often for a variety of non-fire related issues.

I keep a full bucket of water in the shed sink whenever I'm welding. More because in case I get scalded.

Most workshop related fires are going to be Class A & B. To put these out you are best to use CO2 (class A) or CO2/Dry Powder/Foam (class B). Unless you want to have multiple types of extinguisher around (that you then may or may not use on the wrong fire type) you are probably best to keep 1 or 2 CO2 extinguishers in the workshop. Just remember that the CO2 fill remain in the workshop at ground level until you ventilate - CO2 is an asphyxiant.

Dry powder and foam are messy. Fire blankets can quickly become too small.

I personally have several powder extinguishers but only because I used to do car rallying and they are the out of date ones that had to come out of the car.

If you use dry powder just make sure that they are shaken or rotated every now and then as the powder can settle and pack in the bottom of the extinguisher making them less effective when needed.

For screens and covers that don't need to be translucent, consider welding blankets. Either good old fashioned cow hide, or the woven fibreglass type. They can be easily secured to a 20x20 SHS frame with tek screws between a bit of flat bar. Guys or gals welding on cars / equipment / plant / etc will have a heap of these around them for a reason- they cannot ignite- even with a good glob of molten steel on it from torch cutting etc.

Cotton can burn. It burns easier when it has been sitting in a workshop collecting particulate swarf, oils and aerosols etc. All adding to the flammability.

For fire extinguishers, suss out your local 'indepenent' fire and safety store. I know a company that sells their old (but fully operational) out of test fire extinguishers for $5 a piece. Any kind you want. Workplaces have a mandatory timeframe to swap them out, and the testing procedure and replacement includes disposal of them. The place I've shopped at just makes sure you won't be using them as part of a business, ie 'private use only', and you pay cash.

Thanks guys - some good info and ideas there.

I've got a couple of old hardly-used canvas caravan annexes sitting in my storage container, so probably one of the most practical things would be to replace the thin cotton covers with canvas ones.

Good idea about the extinguishers Commander Keen. I'll have a chat to the facilities maintenance bloke at work as I know the extinguisher guys come through regularly doing our ones.

After yesterday I can vouch for dry powder being very messy. Reminds me of an incident at high school where we were messing around in the class room and someone knocked one off the wall. It was the old style "hit end on ground to activate" one, and of course it hit the ground on its end when it was knocked off. Pretty much filled the classroom so there was no hiding what had happened.

Given that the smallest single "space" in my workshop is approx 6m x 6m, there are decent gaps under the large sliding doors and I'm over 6' tall I'm pretty comfortable I'm not going to asphyxiate myself by using a CO2 extinguisher. I'd certainly prefer discharging one in preference to a dry powder type in the future. Hopefully I can get hold of a few well priced cast-offs of both types since my workshop isn't just one big space and its nice to know there's always one nearby.

Some welding blankets are definitely on the list. I see there are 3x3 fibreglass ones on ebay for around $50 each. A couple of those would make good curtains around my normal welding area, and with some thought as to how they were hung - could easily be removed for temporary use in other areas as required.

Edit: Any suggestions on removing dry powder residue from electronics? I'm thinking a bit of a spray down with contact cleaner is probably the best I can do.
No saying the boards aren't already damaged from the fire, but I know they aren't going to like having the dry powder on them long term.

Steve

From my understanding, whilst the dry powder makes a terrible mess, it is the most versatile extinguisher to have.

https://www.fireextinguisheronline.c...u-need-to-know

Originally Posted by OxxAndBert

Edit: Any suggestions on removing dry powder residue from electronics? I'm thinking a bit of a spray down with contact cleaner is probably the best I can do.
No saying the boards aren't already damaged from the fire, but I know they aren't going to like having the dry powder on them long term.

You can try contact cleaner but the powder stuff gets everywhere and I'm sorry to say there's no getting rid of it.
Any residual powder will over time absorb moisture from the air and turn into phosphoric acid.
If a dry powder fire extinguisher is used on a plane that plane is never allowed to fly again.

We had a small (bar fridge size) water chiller catch fire in a dust free clean lab at work that could have been put out with a fire blanket or the misting extinguishers that were inside the lab. Instead the security guard who saw the fire through corridor window grabbed a powder extinguisher from outside the lab and put out the fire. Unfortunately in the same lab there was a bunch of very sensitive electronic research equipment (about the size of 6 large fridges) that also got coated in the powder - made worse because the electronics boxes had cooling fans that sucked the powder deep into the guts of this gear.

The insurance company tried spending $50k on a team of 4 specialist who came in and spent a week cleaning up and set up a large dust free tent inside the lab and took the electronics components apart down to the board level, washed all the parts and dried and reassembled them. The 14, $1200 each 99.997% efficient at 0.3µm HEPA filters that normally scrubbed the air inside the lab were also declared smoke damaged and replaced.

After repeated testing showed continuing problems we covered the gear with cling wrap and waited until the Uni lawyers, the insurance company, and the supplier and installer of the chiller (unbeknownst to us there was a know problem with that model of chiller) that took over two years to resolve. Meanwhile a very fine faint yellow powder could be seen appearing slowly inside the cling wrapped electronics. Eventually the most critical gear was replaced with new gear. When we took the old gear away we had to clean up a shadow of fine yellow dust on the floor where the research gear had stood. The final cost of that exercise including lost research time was about $2 million.

One useful thing to come out of that for me was the 14 smoke damaged HEPA filters were all set to be thrown into the skip. The smoke damage on the filters ranged from sticky soot black goo to a loose pale grey powder. I salvaged four of the least damaged filters and have one in my shed and 3 in my attic. When first turned on they do slowly release a small amount of that smoke but it's nothing compared to what is usually seen in a shed. The smoke cannot be seen but it can be detected with my dust particle counters but over a few hours of continuous running for about 10 hours - no more detectable smoke.

I use a couple of old 0.6 Gal sheets to lay up against anything that might get damaged by welding , grinding , cutting ect,

I've got two dry powder extinguishers in the shop. One in the far corner and one at the door.
They're as cheap as chips at Bunnings: https://www.bunnings.com.au/fire-pro...isher_p0170689
I might look at a CO2 as well.

Apparently you can make cotton less flammable by treating it with Borax.

Borax is what the old cotton racing suits were treated with.
Re electrical stuff like Bobs double pp I have a main switch which shuts off all power next to the door and is turned off whenever I walk out the door.
Except for 3 red pp for the clock, phone and battery recharging.
Also a light switch that can be reached from outside.
Any fire extinguishers should be next to doors out so you can make a decision whether to scarper or have a go at putting it out without getting trapped.
H.

Originally Posted by clear out

Re electrical stuff like Bobs double pp I have a main switch which shuts off all power next to the door and is turned off whenever I walk out the door.
Except for 3 red pp for the clock, phone and battery recharging.

This what I should do because I often have electrical stuff on the go. Apart from battery charging I often have stuff like electrolysis, fume bluing, ultrasonic cleaning and other experiments on the go.

I also need to do something about chemical storage. I do have fuels, lubricants nd some powders separated from each other and the the rest. But I still have a cupboard with assorted solvent, acids and other chemicals that needs sorting.

Back in 2014 I ran poll on the woodie forum.
59 members participated and here are the results

Screen Shot 2022-02-14 at 5.54.19 am.png

The problem with polls like this is it tends to be answered by members that are engaged in this sort of thing. What it doesn't really capture is the number of people that just don't care.

It would be interesting to run the poll again give what has happened since with the increase in size and severity of bushfires being more prominent in the media.

I have repeated the 2014 poll in the woodies forum to see what has happened since.
https://www.woodworkforums.com/f54/f...60#post2271618

With regard to cotton and fires, cotton is one of the surest ways to get a flame for a fire in the bush.

As a youngster we carried a flint from my uncles oxy kit and used small pieces of cotton to spark start some flame under dried wood, always worked.

Fast forward around 20 years and I carried a couple of sealed tampons on my motorcycle travels, turn up, pull out a few very small pieces of dry timber, pull part of a tampon apart and use the flint to spark start a cotton flame.

Mick.

As an aside, I was walking through Aldi today and noted they had 1kg fire extinguishers for around $14.00 or so.

Mick.

Originally Posted by pippin88

From my understanding, whilst the dry powder makes a terrible mess, it is the most versatile extinguisher to have.

https://www.fireextinguisheronline.c...u-need-to-know

Definitely, and just to be clear I wasn't saying that I won't have or use dry powder - I was meaning that if I had a CO2 extinguisher I'd have a crack with that first before deciding to unleash a dry powder and cop the cleanup damage.

As a side note, I was thinking last night that a simple garden sprayer filled with water and readily at hand would probably have sorted the fire I had, and a couple of other smouldering types I've had in the past.
The powered off electronics still wouldn't have liked it, but likely less damaging than the dry powder.

Steve