Help specifying fire extinguishers (powder vs. foam/CO2/water mist)

[dankilb]

Surprised no-one's mentioned the Firepal range. Details and impressive video here: Handy Personal Fire Extinguisher - Firepal United Kingdom

Recommended by the Commodore of my club and he was in the putting out fires business. Not widely available, but can be obtained for £36 from these bods: FirePal FP-50 Compact Fire Extinguisher | Float Your Boat

Wow, impressive indeed! Can really see the potential of this in such a compact (and seemingly effective) form. It doesn't instill the slight unease in me that 'fire sticks' did - in terms of fighting fire on a boat with a live pyrotechnic!

They would be great in an aft cabin or other compact space. On the cost-benefit side, though, you could get several AFFF (or other) compact extinguishers for the same price as one. Perhaps once they come down a bit in price or are more widely available that might sway it (for me at least)?

 

[sarabande]

I have the samew reservatu=ions about Firepal as I do about the earlier 'magic' extinguisher.

If you dig deep into the Firepal pages, past the bit where they say Firepal extinguishers are harmless to humans, you come across a little list.

• Stage 1: Endothermic Cooling. During this process the heat of the fire is reduced and combustion speed is inhibited.
• Stage 2: Chemical Inhibition. Chemical compounds reduce the combustion free-radicals.
• Stage 3: Reduce Oxygen. Finally the fire is starved of oxygen and goes out.

These seem to be very carefully chosen words, and I merely note than in a confined space like a cabin, human beings do like to breathe oxygen.

I am going to stick with water mist (which Firepal avoid mentioning in their technical pages comparing fire types.)

 

[CLB]

These three videos are interesting in that they show the difference between a 2kg CO2, a 3 ltr water mist and a 2KG dry powder all putting out a Class B fire of the same size.

The CO2 took around 7 seconds. The water mist around 4 seconds and the dry powder just 2 seconds. I know they create a mess, but it does show, at least in this scenario, the effectiveness of dry powder.

 

[dankilb]

Quick update - as I went in a slightly different direction for one extinguisher (which will stay onboard full-time and serve as a 'winter' extinguisher) and ordered this:
2.4 Litre AFFF Hand Held Fire Extinguisher – Motorsport Fire Extinguishers
It's a motorsport spec 2.4L AFFF. I went this route after doing quite a bit of research that revealed that the vast majority of AFFF extinguishers freeze and therefore specify an operating temp above 0 degrees (indeed all I could find specify this, except a few much larger 6L+ models). I also read some data sheets from suppliers of the AFFF additive itself suggesting it could be affected by storage below freezing. That's in addition to the damage we know can be done to pressure vessels (calorifiers and such) if they freeze.

I contacted PD Extinguishers directly (I've heard of them from the automotive world) and they responded to say: "Our Foam is an aircraft grade AFFF which is certified to -20 c unlike some manufacturers who add an antifreeze to the foam we use a foam designed to work at very low temperatures."

That works for me... Not cheap, but in the winter I reckon I'm even more likely to do jobs presenting risk of fire (wiring, engine work, wielding the blowtorch etc.). I do work on the boat when it's that cold, for my sins. And the interior certainly falls below freezing - if perhaps not all that often - as the boat is left well-ventilated with dorades open etc.

Still going for a water mist and some additional (regular) AFFF extinguishers, but those will live at home over the winter (and might even come in handy there - although of course hopefully not!).

 

[dankilb]

If you do choose to have a large-ish (2.4L) AFFF extinguisher on the boat - which is also specified to -20°C - it helps if it looks like this! ?

All stainless and very nice indeed. Everything feels 'quality' compared to what's on the boat already, even the bracket.

A mechanical system like this for the engine room:
4.25 Litre AFFF Mechanical Fire Extinguisher System – Motorsport Fire Extinguishers
also looks very tempting, especially for mobo owners or those with more complex systems/installations. I'm sure they'd put together a package with bits tailored to a boaty install (although I'd quite like the 'E' stickers to remind everyone what not to pull!).