Small dry powder fire extinguisher with a hose?

fastjedi

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My surveyor has recommended a manual fire extinguisher + access hole to the engine bay. This implies I need a fire extinguisher with a hose, especially if access is restricted by the companionway steps. All the extinguishers with hoses online are BIG. How have others dealt with this? Can I fit a hose to a smaller fire extinguisher?
 
If you ever want to use it on an engine fire better not use dry powder. It might put the fire out, but the powder is messy and corrosive to metals including wiring- especially bad if the engine is still running and sucks it in. A £20 extinguisher could cause £5,000 damage.

If you don't want to fit a dedicated engine space fire extinguisher the usual thing is a two inch hole with blanking cap, through which you can spray almost any extinguisher. FE type usually used for engine fires.
 
I would challenge the recommendation of a dry powder extinguisher. Reasons have been discussed here many times.

A modern water mist one would be an improvement and the hose is usually about 800mm long
 
Dry Powder should not be used in confined spaces like a boat. You can't breath or see to fight the fire.
 
If you ever want to use it on an engine fire better not use dry powder. It might put the fire out, but the powder is messy and corrosive to metals including wiring- especially bad if the engine is still running and sucks it in. A £20 extinguisher could cause £5,000 damage.

Automatic fire extinguisher systems for expensive classic cars use dry powder - I'm planning to fit one to the DS. The air filter deals with possible ingestion, and in any case you can get (and I will get) a pressure-drop-sensing switch which cuts off the ignition as soon as the extinguisher triggers. Afterwards you hose the engine compartment down.
 
Personally if my engine compartment has a fire last thing in the world I will be thinking about is the damage a fire extinguisher is going to do to the engine.


If you ever want to use it on an engine fire better not use dry powder. It might put the fire out, but the powder is messy and corrosive to metals including wiring- especially bad if the engine is still running and sucks it in. A £20 extinguisher could cause £5,000 damage.

If you don't want to fit a dedicated engine space fire extinguisher the usual thing is a two inch hole with blanking cap, through which you can spray almost any extinguisher. FE type usually used for engine fires.
 
I was looking at an engine bay extinguisher recently, and it specifically said do not use two (in place of correctly sized larger one).

Yes this is sound advice, but have a large engine space under floor , perkins 4236 engine space also incorporates 8 batteries , generator, battery charger and water heater, and I can still go down there and eat my dinner, :) so had to put one on each side and slightly of angle to cover the whole space
 
Personally if my engine compartment has a fire last thing in the world I will be thinking about is the damage a fire extinguisher is going to do to the engine.

But for a small (in relation to boat value) extra cost you can get extinguishers that don't make a truly horrible mess and potentially cause significant damage.
 
Automatic fire extinguisher systems for expensive classic cars use dry powder - I'm planning to fit one to the DS. The air filter deals with possible ingestion, and in any case you can get (and I will get) a pressure-drop-sensing switch which cuts off the ignition as soon as the extinguisher triggers. Afterwards you hose the engine compartment down.

I think the air filters on cars - which have to work in an environment that may include spray and road dirt - are much more effective than those fitted to marine diesels. Mine is a simple sponge (nominally oil-soaked); I'm quite sure it wouldn't stop the fine powder from a fire extinguisher. But it doesn't need to be very efficient; it is located in a sheltered, dry environment, and it's difficult to imagine what exactly it is supposed to be removing from the air! Visual inspection suggests that the answer is that there's nothing to remove - the filter is always as clean as a whistle.

I too have heard that the powder from an extinguisher is quite likely to kill a running engine, or at the very least do expensive damage. However, I also have sympathy with the comment that damage to the engine might be a low priority if I had an engine space fire. But it would depend where I was - a fire hours from the nearest port would put a strong premium on keeping the engine working, and an extinguisher that increases the chances of the engine remaining functional is worth considering. At present I only have dry powder extinguishers, but I'd consider a CO2 or water mist one if replacing them.
 
For an engine room use CO2 not powder for the reasons mentioned, that's what we had.

A CO2 extinguisher will be much larger than a halon-replacement like FM200 or FE36, because it has to displace all the air. The active gases only have to build up enough concentration around the flame to do their job.

For that matter I’m not sure an automatic CO2 system in sizes suitable for yachts is even sold - I’ve certainly never seen one. Where did you get yours?

Pete
 
- a fire hours from the nearest port would put a strong premium on keeping the engine working, and an extinguisher that increases the chances of the engine remaining functional is worth considering...

I think I'd want the fire out first, then worry about the engine.
 
I think I'd want the fire out first, then worry about the engine.

And then be potentially helpless and entirely dependent on others for rescue? Of course, many of us (including me) don't depend on engines alone, but many do. Naturally, if dry powder is the only thing available to put the fire out, I'd use it regardless of the effect on the engine. But a) I'd try and stop the engine before using it so that powder wasn't ingested into the engine and b) if I have an option, I'll use a different type of extinguisher. It isn't about not putting the fire out, it's about choosing a type of extinguisher that will allow you to carry on AFTER the fire is out.

I think there was a Crash Test Video showing the after-effects of letting a dry powder extinguisher off in the boat's cabin - if not that series, elsewhere. The mess and clean-up task was truly awesome, and of course, breathing that stuff is nearly as bad for you as it is for the engine!
 
Your surveyor hasnt kept up with technology! British Standards withdrew their support for dry powder used in confined spaces way back in 2012. Despite that they're still unstalled as standard in caravans, motor homes and of course boats. Cheap to buy with a large profit margin.
It would be relatively simple to rig up a Co2 system using a 2kg Co2 with the horn removed and replaced with copper piping running into the engine bay, along the lines of large vessels but you need to be aware that in a confined space such as a yacht you could end up dead through lack of oxygen.
The solution is new technology Class E also known as dry water mist. That technology was developed initially to deal with commercial deep fat fryers but it was quickly discovered it was also very successful in knocking down just about every other class of fire one is likely to encounter in a normal commercial environment including electric fires. It works by releasing a very fine cloud of deionised water particles. This cools the fire and absorbs oxygen - two sides of the fire triangle - and the fire is extinguished. Best thing is there is absolutely no collateral damage. You could use on on your lunch and be none the wiser. Hope that helps.
There is a small downside. They utilise a double walled cylinder which means that they are larger size for size than a normal extinguisher. i.e. a 1kg Class E is the size of a 2kg ABC
 
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I think there was a Crash Test Video showing the after-effects of letting a dry powder extinguisher off in the boat's cabin - if not that series, elsewhere. The mess and clean-up task was truly awesome, and of course, breathing that stuff is nearly as bad for you as it is for the engine!

Which is why of the 4 extinguishers on board our yacht, not one is dry powder. 2 x AFFF, 1 CO2 and a clean gas auto in the engine bay.

Pete
 
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