Fire In The Hole !!!!!!!!!!

[TTIT]

Bit of a shocker in the shed last night! Spent a bit of time replacing a couple of damaged guide bearings on the bandsaw and tuned everything up as sweet as I could. Cutting some blanks from a lump of very dry, ragged Dead Finish later and smelt smoke! Thought the neighbours must have fired up the combustion heater again and kept sawing. Once I finished the cut and stopped the saw, I noticed smoke coming from inside the saw. PANIC:eek::eek:. Opened the side - patch of dust smouldering away and happily melting my dust outlet:(. I don't have a dusty - ?yet?. Put the fire out and tried to work out where a spark could have come from - no idea - everything looks as it should. Made another cut and away it went again:eek::eek::eek:. Put it out and got my young bloke to watch proceedings under the table while I made another cut to try and determine where the sparks are coming from - none!! Can only put it down to ant dirt in the Dead Finish creating the sparks - used the saw again for hours today with no problem.

My question is - If I had been running a dusty, what would have happened????:confused: Fire in the dusty???:confused:
When I get one it would be out the back of the shed where I cannot see (hear) it - doesn't seem like such a good idea now:confused::o:confused:

[Grunt]

Fire In The Hole !!!!!!!!!

Cut down on the chilli

[Stuart]

My question is - If I had been running a dusty, what would have happened????:confused: Fire in the dusty???:confused:
When I get one it would be out the back of the shed where I cannot see (hear) it - doesn't seem like such a good idea now:confused::o:confused:
Probably not, but certainly there is a possibility. The distance to travel and the airflow would probably have meant that whatever sparks were being generated would have finished burning by the time they found another source of combustible material. However, it is by no means an ideal situation. One suggestion for when you do set up the dusty - get a cheap smoke alarm - costs next to nothing, and could save you from a dangerous development! (Come to think of it, after your experience, I will be taking my own advice!) (Especially seeing as mine is in an adjacent shed, along with my main wood storage racks..... :eek: )

[BobL]

. . . . One suggestion for when you do set up the dusty - get a cheap smoke alarm - costs next to nothing, and could save you from a dangerous development! .. . .

Smoke alarm, that's a bloody good idea. I've already has a (small) fire in my shed. One Saturday morning in the middle of a windy rain storm one of the house circuit breakers turned off. I reset it and it tripped again. I walked the house and pulled out every appliance, still tripping. Then I remembered the shed. Opening the shed door I could smell smoke and a few wisps were rising from one of the powerpoints underneath the window. I turned off the power opened up the powerpoint which was chock full of sawdust and an ants nest. The sawdust was wet from the rain that had come in from underneath the window and mixed together with a bit of mushy ant acid, had created a circuit which was still smoking.

I guess it was probably lucky we were home - smoke alarm wouldn't have helped much if we weren't. Anyway I'm still getting an alarm.

Cheers

[echnidna]

Dusties have caught fire just from the sparks from cutting a nail, so fire is certainly a real possibility.

[doug the slug]

One suggestion for when you do set up the dusty - get a cheap smoke alarm - costs next to nothing, and could save you from a dangerous development!

can a cheap smoke alarm differentiate between smoke and fine dust? :confused: :confused: :confused:

[Stuart]

good point. Or perhaps that's worthwhile too - "Warning, warning, your lungs are getting rooted"!

[doug the slug]

so we need a cheap smoke detector that cant differentiate between dust and smoke in the workshop and a smoke detector that can differentiate in the top of the cyclone bucket in case theres a fire in the ducting system or the cyclone :confused: :confused: :confused: :confused: :confused: :confused: . geez,just when i thought i had it all figured out :mad: :mad: :mad: :mad: :mad:

Next question - how are we going to hear the muffled scream of the smoke detector in the dusty over the racket being made by the thicknesser and through our hearing protection we all wear?

[TTIT]

so we need a cheap smoke detector that cant differentiate between dust and smoke in the workshop and a smoke detector that can differentiate in the top of the cyclone bucket in case theres a fire in the ducting system or the cyclone :confused: :confused: :confused: :confused: :confused: :confused: . geez,just when i thought i had it all figured out :mad: :mad: :mad: :mad: :mad:

Next question - how are we going to hear the muffled scream of the smoke detector in the dusty over the racket being made by the thicknesser and through our hearing protection we all wear?

Thanks for the ideas guy's - I was hoping someone would tell me that dusty's miraculously extinguish sparks somehow but it sounds like I'm gonna have to be extra vigilant when I'm cutting some of the dodgie desert timber I use out here.
Think I might just train the dog to bite me on the ankle when it smells smoke - it's always hangin' round my feet in the shed anyway!

[chrisb691]

can a cheap smoke alarm differentiate between smoke and fine dust? :confused: :confused: :confused:
Ionisation alarms, ie the cheap ones that most of us have, alarm by the detection of carbon(?) produced as the result of combustion. Therefore, they should not be triggered by dust.

Having said that, A Current Affair had an article on tonight, that basically says these are near useless, as they wont detect the smoke from a slow burning (smouldering) fire. You need the photoelectric type to be safe.

The article can be found http://aca.ninemsn.com.au/stories/2117.asp

I have 10 of the Ionisation alarms in my home, religeously change the batteries annually, test them all monthly, and was feeling safe. Now I've got to go out and start replacing them all. BUGGA

[bsrlee]

From the smoke alarm POV - get one of the alarms with a built-in light - just position it so it shines at you rather than into a cupboard. They are sold as being good for the hard of hearing as well as providing some light for escape if the main power fails due to the fire.

As for the fire-in-the-sawdust-bin problem - I'm aiming to use a steel bin as a drop box, I might have to put some sort of liner in it & dump a few litres of water in there to soak the dust.

[Stuart]

In the mailbox tonight- the latest Choice magazine. The cover article- smoke detectors. How ironic.

Good point here - given as Doug correctly pointed out the crap atmosphere stuffing up some particle detectors, and definitely stuffing up photoelectric types, perhaps heat detector types would be the go.

[Markw]

Not sure what type I have fitted but the damned things go off when mowing the lawn - 2 stroke mower but not that much smoke - you cant see the smoke produced.

Just a mid priced unit from bunnies

[chrisb691]

Not sure what type I have fitted but the damned things go off when mowing the lawn - 2 stroke mower but not that much smoke - you cant see the smoke produced.

Just a mid priced unit from bunnies

If it's got a radiation warning on the back it's an ionisation type, if it hasn't, then it's a photoelectric.

[Markw]

Yep its one of them newcleer atom bomb thingys.

[doug the slug]

ok if i may re-hijack the thread back to where it came from......

i dont think a smoke alarm in the cyclone system is the way to go as i doubt that i would hear it anyway, and as discussed previously, false alarms may be prevalent.

instead i am going to cut a perspex window into the collector drum. this will serve dual purposes. firstly, i will be able to see when the drum is full. secondly, and most importantly, if i smell burning anywhere i will be able to tell at a glance if its in the cyclone collector.

but if it is in the collector, what to do about it? best thought so far is a hole with a rubber grommet in it that i can pop out and stick the garden hose or fire extinguisher nozzle in. any other ideas???

[bsrlee]

How about a tap in the side of the drum with the delivery side INSIDE & a click fit hose connection screwed onto the supply side OUITSIDE the bin - then you can clip the hose on without opening the tap before water is available. This should avoid stirring up a smouldering fire with ectra draught.

[doug the slug]

thanks for that bsrlee, i had thought of the influx of air. However im looking at a 20mm or so hole being unplugged in one second and replugged in the next with a hose or fire extinguisher nozzle. hopefully just before i unplug the hole i will have just turned off the dusty, so the fire should actually be starving for oxygen anyway.

thinking a bit further into it, if a fire is going for a bit longer than i would like, the tap on the outside may get too hot to touch and prevent me from implementing the fire drill. whereas a rubber grommet blocking a hole will soften or burn out and be easier to push out with the implement hung on the wall beside the cyclone bucket for that purpose. Hope this makes sense.

Bsrlee, sorry if it looks like I'm giving your idea a caning. in principal it's good and may workin other peoples setups. its actually given me an idea for a future project too........;)

[Skew ChiDAMN!!]

:eek: Don't just pump water in through an 'ole!!

That'll stir up the dust and chances are it go BOOM! As any firefighter will tell you, in a dust fire you SPRAY, not squirt. If I was going to add fire-suppression to my dusty, I'd settle for a cheap(ish) fine-mist sprinkler in the lid of my seperator, using a click-on hose fitting on the outside as already discussed. There should never be enough of anything getting through to the DC bag for me to worry about that side. Unless I've been ruly, ruly slack in emptying the seperator. OK, so mebbe I should think about doing something there as well... :rolleyes:

Personally, I won't bother. My seperator's a 44 sitting next to the back door of the shed for easy emptying. In case of internal fire, I'd just yank both flexi's, tip 'er on 'er side and roll 'er into the back yard. Then it's the gardener's problem. ;)

[doug the slug]

:eek: Don't just pump water in through an 'ole!!

That'll stir up the dust and chances are it go BOOM! As any firefighter will tell you, in a dust fire you SPRAY, not squirt.

thanks for the input Skew, will research this one a bit further. chances im wrong but I was thinking that in an enclosed space with a severe shortage of oxygen as soon as the dusty is switched off, that the potential for an explosion would have been very low. in any event im still looking at fire extinguisher options and their suitability. if its water from the hose that i go for it would be a spray in any case, with an option to spray the outside as well to cool the cyclone system and reduce potential for the fire breaking out and spreading.

[Skew ChiDAMN!!]

This thread has me reconsidering a few things. For a while, I had the shed on the same security monitoring system as the house (3rd-party monitored motion & smoke detectors) but we had the smoke detectors removed from the shed. Too many fal$e alarm$ triggered by dust. :( But I've been feeling more concerned about the chances of fire in the seperator since I recently caught a couple of blokes dropping smoke butts on the floor... from where they schloop straight into the floor-sweep. :eek: Admittedly I do the same but at least I make sure they're out before I drop 'em!

A suppression system inside the bin is a damned good idea but without some form of early warning, like before the flexi-ducts into/from the bin burst into flame it's as useful as a loaded gun in a locked cabinet. :rolleyes: If smoke detectors aren't the answer, I wonder if a simple temp. sensor would work? Airflow'd cool it down, perhaps below detection temp, but I wonder... what if several are mounted in parallel (so any one of 'em can act as a trigger) on rod running up the middle of the bin? Say they're spaced every 6" or so... Surely the odds are pretty reliable that at least one of 'em would be in the "hot spot?"

Feel free to ignore me, I'm basically just thinking out loud. ;) There's gotta be some cheap & effective way though.

[doug the slug]

I wonder if a simple temp. sensor would work? Airflow'd cool it down, perhaps below detection temp, but I wonder... what if several are mounted in parallel (so any one of 'em can act as a trigger) on rod running up the middle of the bin? Say they're spaced every 6" or so... Surely the odds are pretty reliable that at least one of 'em would be in the "hot spot?"

Feel free to ignore me, I'm basically just thinking out loud. ;) There's gotta be some cheap & effective way though.

I wonder if a cheap adhesive thermometer like they use for home brewing stuck to the outside of the collector would do it? It wouldnt give an audible signal, but it would be a quick way to visually check if something suspicious happens, like a shower of sparks from the blade when you hit the old nails. but then the brewing thermometers only go up to 40 degrees, maybe something similaris available for other purposes. lets keep throwing the ideas around