Dry powder extinguishers used to be sodium bicarbonate and maybe some still are but a different powder (a phospate ??) is now used to make them suitable for a wider range of fire types.( AB&C rather than just B&C ???)thank DeepJoy for confirming what I had read somewhere but couldn't put my finger on, that the powder is Sodium Bicarbonate.
IIRC it melts and encases the "fuel" when that is solid and so seals it off and helps prevent re-ignition. Bicarb was not good at preventing re-ignition of solid fuels eg wood.
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09-03-10, 20:52 #61Sea Wych Owners Association: www.Seawych.org
09-03-10, 21:10 #62Registered User
Location : Miskin, South Wales
- Join Date
- May 2004
Ammonium phosphate is the ABC type of dry powder (Monnex), and is what you might find in 'industrial' dry powder extinguishers. Potassium bicarbonate is also used. However, the type which tend to be used on small boats like ours are 'domestic' typem and will most likely be sodium bicarb. I work in the chemical industry, and we still use sodium bicarb for many installations.
The bottom line remains the same though - it is better to have any type of extinguisher on the boat than to avoid having one because of possible health concernsAll the best
09-03-10, 21:29 #63Registered User
Location : Scotland
- Join Date
- Mar 2002
09-03-10, 21:46 #64Registered User
- Join Date
- May 2007
What's the yellow area in your graph, Ubergeekian?
09-03-10, 21:53 #65Ammonium phosphate is the ABC type of dry powder (Monnex), and is what you might find in 'industrial' dry powder extinguishers.Sea Wych Owners Association: www.Seawych.org
09-03-10, 22:26 #66
I'm an elfin safety bod and also conduct fire training.
Elfin safety spend a lot of time dispelling stupid "health and safety sez so" rumours.
How much time do you think your puny 2k ABC in a marine environment will last? About 10 seconds if you are lucky, have it serviced every 12 months and keep giving it a shake now and then. How long do you intend to hang around?
The smoke in the cabin will do for you far more efficiently than ABC powder.
As for CO2, read your fire extinguisher placards "not for burning paper or textiles" it sez. A great way to make a small paper or textile fire into many fires.
True, powder are not ideal for enclosed spaces and can cause transient breathing difficulties, but they are certainly not classed as hazardous.
However, it would be wrong to post without divulging my first choice of extinguisher on a boat, which would be AFFF foam. Size for a 34b rating would be around 3 kg. You should have at leat two of these.
Better to have several smaller type 34b ones located around your boat, than one large one, for if the large one fails or you can't reach it........
Of course bigger is better, but who wants 9 litre foam extinguishers everywhere. Far better to have enough extinguisher and spend more effort preventing fires from occurring.
Last edited by tinkicker0; 10-03-10 at 06:05.Avatar = Bailey - Gone but not forgotten.
10-03-10, 06:49 #67Peter
10-03-10, 08:01 #68Registered User
Location : Windsor, UK
- Join Date
- Nov 2006
Galadriel - unfortunately we are no longer permitted to carry halon extinguishers on commercial aircraft, we now use BCF. Id like to know why we can't use BCF on boats - having used it in galley fire training drills it is very very effective.
And yes, put your mask on before helping anyone else in an aircraft decompression - crews are taught to sit down immediately and don a mask - even if that involves sitting on the nearest passengers lap and grabbing the spare mask that is supplied at every seat row. Bizarrely, we're then told to get the passenger to put their arms around us and hold on! (to restrain the crewmember during the drop-out-the-sky descent.)
Vics - any idea why we aren't allowed BCF on boats?
10-03-10, 08:13 #69Answers to some technical queries at http://coxengineering.sharepoint.com
10-03-10, 08:14 #70