Way too much of the time (it detracts from sailing), I work in a remote health centre. Chubb turns up annually and checks the fire extinguishers. The bloke pays special attention to all the gas/powder extinguishers - like those usually used in yachts.
He inverts the extinguisher and whacks it with a plastic mallet till the settled/packed powder breaks up and moves, then gives in a few further whacks and shakes to ensure its well and truly loosened up. He reckons this process is even more important for extinguishers used in vehicles and boats, as the fire retardant capacity of the extinguisher is severely diminished if the powder doesn't mix with the gas.
Given the potential issues with fires on boats, I thought this info worth sharing!

Good advice, I'll give all mine a check and whack with a rubber mallet.
cheers Richard

Yep just finished a fire drill and one of the points was that the powder extinguishers, aka the ones with the White band should be inverted regularly. And yes in theory their a good all rounder but on a reasonably decent class B ( flammable liquid) fire the effect was not impressive but we where out door, foam was the only type that took the fire out.

Good topic post Bushdog... great advise

The guy that regularly service our fire extinguishers performs the same tap and shake routine.
I told him that on my boat I had 3 powder types and that after hearing the story of the guys that had a fire on board and could no longer go below to fight the fire after they discharged the contents of the powder type fire extinguisher in the cabin... that I wanted a fire extinguisher that wouldn't fill the air with particles,,,. He suggested a "JE-50 nano-particle fire extinguisher". He told me his company had tested them and had found them extremely effective, so I bought one from him.

westpeacehorizons.com/product-detail/je-50/

Mine are installed on their side , so the rocking of the boat keeps the powder from compressing .not sure about my theory ??

Thanks for the tip, will do this periodically now.

What's the bet that most people have their extinguishers next to where the fire is likely to be and if that is the case how do you ever hope to be able to get to it in order to use it. You may be able to get to another extinguisher in certain cases, but can you get to one quickly enough for it to be effective?

Good point loose change, and to add to it in my recent experience the little 1kg jobs that I'm confidant that we all have on board, will be disappointing as to out put of retardant.
maybe ok if your able to nip a blaze in the bud. And of course we all have a fire blanket obvious and accessible in an area like the galley

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jbear said..
Mine are installed on their side , so the rocking of the boat keeps the powder from compressing .not sure about my theory ??

I asked about that, as my car extinguisher is kept horizontal. Bloke thought is was better - larger surface area = less depth = ? Less compression, but still worth giving them the occasional tap!

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LooseChange said..
What's the bet that most people have their extinguishers next to where the fire is likely to be and if that is the case how do you ever hope to be able to get to it in order to use it. You may be able to get to another extinguisher in certain cases, but can you get to one quickly enough for it to be effective?

Two extinguishers mounted on the forward bulkhead, Galley at the rear of the saloon. If there is a fire in the saloon these extinguishers will help you escape past the fire, pointless trying to fight it! If your in the cockpit and there is a galley fire then I will not be going anywhere near it.

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Jolene said..
Good topic post Bushdog... great advise

The guy that regularly service our fire extinguishers performs the same tap and shake routine.
I told him that on my boat I had 3 powder types and that after hearing the story of the guys that had a fire on board and could no longer go below to fight the fire after they discharged the contents of the powder type fire extinguisher in the cabin... that I wanted a fire extinguisher that wouldn't fill the air with particles,,,. He suggested a "JE-50 nano-particle fire extinguisher". He told me his company had tested them and had found them extremely effective, so I bought one from him.

westpeacehorizons.com/product-detail/je-50/

I've also heard good feedback about the generation of extinguishers. Was it expensive?

Fires are most likely to be fuel or electrical. The need for safety with gas was discussed extensively on some recent posts comparing stove options.
Reducing available oxygen is a major component of effective fire management. I read somewhere that I it's good to have a small vent where you can aim an extinguisher into an engine compartment without having to remove access panels, and have done this with my current boat.
Given the recent suggestion that the Qld boat fire started behind the electrical panel, and discussion about hinged panels etc, I might to the same there.
If I boat burns when no one is around it's a loss. If a boat burns with people on board it's a potential tragedy. It's worrhwhile checking your fire alarm when you give the extinguishers a tap!

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Bushdog said..

Jolene said..
Good topic post Bushdog... great advise

The guy that regularly service our fire extinguishers performs the same tap and shake routine.
I told him that on my boat I had 3 powder types and that after hearing the story of the guys that had a fire on board and could no longer go below to fight the fire after they discharged the contents of the powder type fire extinguisher in the cabin... that I wanted a fire extinguisher that wouldn't fill the air with particles,,,. He suggested a "JE-50 nano-particle fire extinguisher". He told me his company had tested them and had found them extremely effective, so I bought one from him.

westpeacehorizons.com/product-detail/je-50/

I've also heard good feedback about the generation of extinguishers. Was it expensive?

It was about $60 to $80. I can't remember exactly as it was added to the bill for servicing the other extinguishers .