Thread: Fire Extinguisher Fun

Originally Posted by irony

I've been told I'm full of p!55 and wind so I pee on any fires in my workshop. Not so good for electrical fires though...

yeah..it might tickle your fancy a tad

Ok now I'm confused... I have an ABE dry powder extinguisher, which will put out the fire, but you guys are telling me it will ruin all the machinery.. so what's the best course of action, let it burn?

I have CO2 in the electronics workshop, but, according to what I can find out that's no good for outdoors or general fires..

I can't afford $1200 per extinguisher... So what's the best choice.. I'm back to dry powder being the best all round choice? Or is Simon going to get us all some free Vapourizing Liquid ones..


Ray

Originally Posted by RayG

Ok now I'm confused... I have an ABE dry powder extinguisher, which will put out the fire, but you guys are telling me it will ruin all the machinery.. so what's the best course of action, let it burn?

I have CO2 in the electronics workshop, but, according to what I can find out that's no good for outdoors or general fires..

I can't afford $1200 per extinguisher... So what's the best choice.. I'm back to dry powder being the best all round choice? Or is Simon going to get us all some free Vapourizing Liquid ones..


Ray

the later sounds like a bloomin good idea Ray

I cant afford them either...I have a couple blankets and a couple of powder and a wet extinguisher.... and lots of non imflammable refrigerants which should just about smother any fire if ... even the cat... possibly,... as it lives in there...lol

I'm curious if the ones that went pfffft and little else indicated correctly on the gauge prior to use? Was there any indication that they may have been running out of puff? I have one in the kitchen, and one in the workshop. Touch wood I haven't yet had to use one as yet.

Fire blankets are also a very good idea, and I need to get some more. As far as reusing them, that may be the case for general fires, but I made the mistake of using one as a heat shield when silver soldering one time and it destroys the blanket. Contrary to popular belief they ARE affected by heat, just at much higher temperatures than other fabrics. I'm still finding little pieces of fire blanket around the place from where it disintegrated.

Originally Posted by Pete F

I made the mistake of using one as a heat shield when silver soldering one time and it destroys the blanket. Contrary to popular belief they ARE affected by heat, just at much higher temperatures than other fabrics. I'm still finding little pieces of fire blanket around the place from where it disintegrated.

Yeah, I wouldn't recommend using them as a flame shield as such, by welding blanket I meant that when welding cast iron for example I preheat what ever I'm welding then wrap as much of it as possible in a fire blanket leaving only the bit to be welded exposed. This keeps in the heat a lot longer than having the whole thing exposed. I've used the same blanket for a couple of years now and only scorched through it in a few spots where I got too close with the arc.

Originally Posted by Pete F

I'm curious if the ones that went pfffft and little else indicated correctly on the gauge prior to use?.

The first one, I can't say as I didn't look before I hit the button, but on the other one the pressure gage was well below the correct level, maybe half way towards zero..

Ray

Originally Posted by RayG

Ok now I'm confused... I have an ABE dry powder extinguisher, which will put out the fire, but you guys are telling me it will ruin all the machinery.. so what's the best course of action, let it burn?

I have CO2 in the electronics workshop, but, according to what I can find out that's no good for outdoors or general fires..

I can't afford $1200 per extinguisher... So what's the best choice.. I'm back to dry powder being the best all round choice? Or is Simon going to get us all some free Vapourizing Liquid ones..


Ray

Hi Ray,

Look at the end of the day ANY extinguisher for fire suppression system is going to be better than nothing. What I would do if I were you is look at where your greatest risk is. Ask yourself, what is the most likely cause of a fire and what will most likely be burning. Do you do most of your high risk activities inside the shed or outdoors?

For outdoor use, you cannot go past a water extinguisher or even just a hose on a reel for most fires. If you deal with moderate volumes of flammable liquid outside then either a foam extinguisher or a dry powder. As mentioned earlier, CO2 and vaporising liquid have a limited effect outdoors and have almost no effect if windy as the CO2 or vaporising liquid will be blown away before they can displace the oxygen to smother the fire.

For indoor use, once again a water extinguisher will be good for sawdust, paper, wood, plastics etc. If there is an electrical hazard then you have the option of isolating the power (assuming this does not have catastrophic affect on your business) will render any electrical hazard safe and water can be used. For a flammable liquid or oil fire then you really need to use something other than water. You basically have the option of a CO2, dry powder, foam or a vaporising liquid extinguisher. Lets cross the vaporising liquid off the list since they seem to be ridiculous in price, that leaves CO2, foam or dry powder. If you mostly use your shed fully enclosed with the door closed so there will be little air circulating then you may get away with a CO2 but you need to realise that you have to be pretty close to the action with a CO2 extinguisher, it has a throw of no more than about a metre. A foam extinguisher is similar to a water but it has a 6% mix of AFFF (Aqueous Film Forming Foam) or ATC (Alcohol Type Concentrate) and the nozzle has an aspirator that mixes the foam solution with air to make finished foam. It will form a nice blanket on horizontal surfaces and will also resist shear stress to an extent and hang on vertical surfaces too. It will produce a protective blanket of the the spilt fuel and remain long after the fire is extinguished, preventing any chance of flash back if the fuel is heated to it's flash point from the fire. ATC foam extinguishers are better if you have alcohols in storage. Alcohol tends to break down AFFF foams as the water in the foam is miscible with the alcohol.

If you manage to obtain a water extinguisher pretty cheaply, you can convert them to foam (I do not recommend this for the workplace or in industry) by mixing the foam concentrate when filling with water and changing over the nozzle to a foam nozzle.

The best all round extinguisher is the good old dry powder, that's why they are so popular. They are cheap, easy to use and cater for most fire that are likely to happen in the home or shed, BUT they are messy.

At the end of the day, for cost effectiveness I would have a water (or foam) and a dry powder. Choose the best one at the time of the fire. Use the powder extinguisher as a last resort and use it sparingly!

Hope this helps...

Simon

Originally Posted by simonl

Use the powder extinguisher as a last resort and use it sparingly!

I've just spent 2 minutes unmercifully beating my powder extinguisher with a rubber mallet.

Cant say I've ever seen one discharged. How difficult is that powder to clean up? Does it vacuum up, or need to be washed off?

Going to check the one that hangs in the pantry door tonight when I get home. Put that in when we built the place, its probably 19 years old. Yikes.

Regards Phil.

I'm sorry if my post about the powder extinguishers have raised concern about using them in metal workshops.
My laboratory example where custom made electronics are used to make measurements at the one part in a million range is not a useful reference for the average shed owner and please do not let this stop you using a powder extinguisher in your shed if there is a fire.

The powder ones are messy but based on the amount of mess and level of (un)cleanliness in sheds I have seen in DIY sheds around the place I'd say most folks don't have that much to worry about it.
In terms of grit, if you have ever used abrasive grinders or cut off wheels, oxys, welders in your shed, ox and don't clean up the whole shed and machinery afterwards, the shed and machine surfaces will contain fine abrasive grit, oxidation product, metal dust and swarf anyway. Once cleaned up after a fire, extinguisher powder is not going to add that much more mess or grit into the air and onto surfaces. In fact it might be the cleanest your shed will be for some time.

In terms of electronic/electrical damage any running VFDs and motors with fans may be affected because they will draw the powder dust into themselves. Unless the powder is blasted directly onto them, any non-operational units should be OK. So the fire may cost you a couple of VFDs and motors, but burning the whole shed or neighbourhood down could cost you a lot more.

As Simon says the Vaporising liquid extinguishers are not as effective against solvents/paint/combustible liquids or flammable gasses and although it sounds like Simon knows what he's doing in using Vaporising liquid extinguishers against these sorts of fires, I doubt other people would and I for one do not want to stop and think about what extinguisher to use. I would only be looking at non-powder extinguishers f you run a clean workshop (no abrasives/welders), and/or have a lot of expensive electronics, then another type of fire extinguisher might be worth looking at.

Despite this I think it has been a good thread for raising fire awareness, and haven't we just had fire awareness week?

20 years ago our then 11 year old son set fire to our bathroom by flicking what he thought was a dead match into a wicker style rubbish bin full of cotton balls and tissues. He then tried to smother the fire with a towelling bath mat but that too caught fire. He then got worried about the smoke and turned on the exhaust fan! Then he closed the door and came and told me what had happened.
I rushed inside and just then the house smoke alarm went off. When I opened the bathroom door I was hit in the face by a wall of acidic smoke (by then the melamine cabinet was on fire) so I dropped to the food and was able to crawl into the bathroom and turn on the shower (on the end of a flexible hose) and douse down the fire. It was a good lesson and just after that we bought our first fire extinguisher (now we have 5).

Originally Posted by RayG

The first one, I can't say as I didn't look before I hit the button, but on the other one the pressure gage was well below the correct level, maybe half way towards zero..

Ray

Ok, that's good. Well, bad for you, good for the rest of us I was afraid you were going to say something along the lines that they were indicating just fine. On your suggestion I checked mine and they're indicating just fine.

I recall as a younger lad having a small fire in my backyard (the incinerator caught the back fence rails alight and it spread a little), not a big fire by any stretch of the imagination. I only JUST got it out with a garden hose. A few more minutes and I wouldn't have caught it. You may think a lot of water comes out of a garden hose ... until you try to put out a fire with one! If ever there was a source of the expression "You may as well pi$$ on it" it must surely come from trying to extinguish fires with water, at least the amount that comes out of a regular hose.

Phil, also as a lad I gave a dry powder extinguisher a VERY small squirt inside, "just to see what happened". The white crap goes EVERYWHERE! It was literally a microsecond burst. Needless to say my mother hit the roof when she came home to find the entire inside of the house covered in very fine white powder.

Fire extinguishers are a form of insurance. They provide the means to enable us to control a fire before it reaches a size where it can not be controlled. The fire extinguisher is our first level of suppression in the fire cycle. If we cannot initially control then we need to contact a fire brigade who are better resource to control it. While some extinguishing mediums may be messy, is it better to control the fire and extinguish it, then worry of the mess it may make. If it grows in size and requires a fire truck are we going to be worried of the initial mess. It is better we review our own work area and have the correct fire extinguisher for our situation then to be worried about the mess if an extinguisher is used. If not sure of what fire extinguisher to have, seek assistance from those in the know - be ready to act before the event not after.

Do not despise the Garden Hose, but make sure it is the right one! Not a great expense to get a garden tap installed with a 19mm copper service to it instead of the usual 12mm pipe. Then buy a length of 19mm reinforced garden hose and put a ball cock and nozzle on the end. A short piece of 6mm id tube is OK and will throw a jet 20 metres, so you don't need to get too close. Hang the hose in loose loops over one of those hose hangers, and remember to turn on the tap to pressurise the hose and stop kinks before you throw the whole bunch of hose on the ground and run with the nozzle.
Have been very glad of this setup a few times when welders and grinders have lit up something unexpectedly. Cheap and effective for the home yard or shop where a hose reel is not mandatory.
Made the mistake of enquiring the cost of an installed fire hose reel once. Would need to connect a 25mm water meter, then a 25mm water line to the hose, and the whole lot would need to be surveyed and approved by the local Fire Service. Could have bought a new car for the estimated cost. It was not mandatory for my shop size, so the garden hose solution won, and proved effective when needed.
Combustor.

From Rural Fire Service pocketbook - types of extinguishers, classes of fire:

A Ordinary combustibles (wood, paper, plastics etc)
B Flammable and combustible liquids
C Flammable gases
E Fire involving energized electrical equipment
F Fire involving cooking oils and fats

So for example an ABE extinguisher would be for solids, liquids and electrical fires. But they say it's also OK for gas fires. It's red with a white band.
A carbon dioxide type extinguisher is OK for everything except gas fires, red with a black band.

Jordan

Hi Jordan.

Dont forget electrity is not considered a class of fire as such thats why its represented in parentheses (E). Its a hazard. Once you remove the hazard (ie isolation) then the class of is whatever is burning.

Also you left out a class of fire in your list- class D flammable metals

Cheers

Simon