Magnesium Burns.... its crying time

[ClickClickBoom]

Having been to the fire academy and worked as a firefighter for a medium sized municipal fire department, I will a attest to the tenacity of magnesium fires. Magnesium has a few nasty tricks up its sleeve. When burning magnesium is exposed to water(H2O) the extreme energy of the the fire causes decomposition of the water into hydrogen and oxygen. Magnesium can be put out with huge volumes of water, the rationale is flooding will lower the overall temperature, bringing the metal below the ignition temperature. Simply put a 1 1/2" hose is not big enough for a car sized fire. Multiple large bore hoses are mandatory and if involved enough might, not suffice.
So many here swear by Halon for their precious iron, but truth be told, I won't waste the time and energy with it. I carry a 2 1/2 lb portable Purple K extinguisher in the car for Class B fires. If 2 1/2 lbs won't do the job 25 lbs will probably won't either.
As with everything in fire, prevention is a more successful strategy. Proper fusing, replacing aged hoses and carrying a minimum of a 2 1/2 lb ABC dry powder extinguisher might save the day if caught early enough.
The energy in a car battery along with 20 gallons of gas and a couple hundred pounds of aluminum/magnesium creates a nightmare for firefighters.
My shop has multiple ABC dry powder extinguishers, a 10Lb Purple K, and several H2O/compressed air extinguishers. I also have installed several hose bibs to corners of the property, using 3/4" hard lines.
Hell, I even have a 5 gallon backpack wildland fire pump kit.
Halon is not a magic wand of firefighting tool, and to quite frank, 10 lbs won't do squat.

[RSTarga]

Does anyone remember the Honda F1 Car of Jo Schlesser? The chassis was all magnesium.

[ian c2]

I 0nce worked in Norway and as part of the offshore thing we were trained by their fire department .
Iirc the unofficial “5 second” rule was , if you see the fire within 5 secs of starting , spend 5 seconds getting an extinguisher , 5 seconds putting it out , if that doesn’t work run for 5 seconds and call fire dept , then run as long and as far as you can !

Diesel fires are pretty cool too .
They used that as the piece de resistance of the training .

Not much help to the posters here I know , but a battery kill switch and well designed and maintained electrical and fire suppression/alarm system helps immensely .

In regards to interior mounted extinguishers , I had the math done and it took 2 to “drown” a cabin fire .
And let’s face it , my car could be on fire as I commute to work at high speed as I’m late or “racing the clock” and the first I’d know about it was loss of power or instruments .
I have one facing front and one facing back towards engine , but to be h0nest I wouldn’t even reach for the trigger unless the interior was on fire and I could hold my breath while I got out .
I’d just get to the side of the freeway as fast as I could , grab my coffee , phone and cigs , and run .

I thought about a fuseable charged line into the engine bay , but from what I’ve seen a portable in-cabin extinguisher is mainly an escape tool and I’m hoping I’ll get out before I need an escape route .

I carry 2 , and If I can shoot one through the grills on a front or engine fire , awesome .
If not it’s just a car ....

I’ve restored a fire damaged 90s 911 in the past (allways a rear wheel arch fire where the charcoal canister is ) and they’re easy as you’re just replacing melted plastic and painting , but these days you can’t even do that as the burnt plastic is carcinogenic !!

In both posters pics on this thread , I feel sorry for them and hope they get fixed up .
But at the end of the day it’s just a car . A convenience . Not even practical so not a necessity .
It’s your health that matters .
And it’s great to see both are ok/doing well .

[TheWizardFromAu]

For anyone interested there are 3 brand new lightweight Element fire extinguishers going cheap on eBay at the moment.....
https://www.ebay.com/itm/323839687964

[piscator]

Flojo posted this fire suppression system in another thread. This seems like an obvious addition to any Porsche fire fighting arsenal. I'd love to get one of these, but the website isn't very specific about which model would be best. Anyone have experience with Blaze Cut or something similar?

Description | BlazeCut

I'd be very interested in other automatic extinguisher systems you guys have seen. I was lucky to put out a small boat fire once and found the experience terrifying! I'd sacrifice space in the trunk for a small tank supplying an automated system to go along with my cabin mounted extinguisher.

Any suggestions or experience with these?

Thanks to all the posters on this thread for the strong warning to pay closer attention to fire prevention!

[GothingNC]

Originally Posted by dad911

That's the car from 1st post?

Please tell us the story.

Yes, he bought it back from Haggerty and it took a long time to get it back from the body shop.

[Jack Stands]

Do the foam extinguishers work any better than dry chemical or halon? It seems the foam may do a better job of cooling the area and blocking air from the flame.

[1980 SC Targa]

Gary's car is back home :-)

AMAZING! Kudos to him for not giving up on it. Like dad911 I would very much like to hear the story of it's rescue. Every one of these original cars we can save is a victory.

[onboost]

Originally Posted by GothingNC

Yes, he bought it back from Haggerty and it took a long time to get it back from the body shop.

Glad to see/hear that G has it back in his possession! Excellent!!

Paul-

[GothingNC]

Back on the road :-)

[john walker's workshop]

Excellent!

[Bill Douglas]

A fine job done.

[Bigtoe32067]

Wow. Congratulations.
I don’t understand how large amounts of water can put out magnesium fires when it burns underwater. Am I missing something or am I just plain confused? Seriously?
Tony

[RDM]

And the next question- do we have clear word on what started the fire and (therefore) how we can prevent this happening to us? OK- electrical short on the big, unfused starter / alternator cables.

What to do?

[stownsen914]

Very nicely done!

[gamin]

The probable cause (aviation lingo) appears to have been an electrical short where the engine harness passes over the left air duct on it's way to the 14 pin connector. Very close to left carb and gas. My sharp eyed friend Jim found a piece of that wiring welded to the duct. The take home message in all this is that wiring, especially engine, deteriorates with age and numerous heat cycles. Lesson learned.
Car now has 79 euro 3.0 9.3cr PMO 46's and SSI's and suspension and brake mods. Using a 911/00 4sp trans and love it. No more weak dogleg first gear. Also SC oil tank and trombone cooler. 190 hottest that I've seen on a 90+ day. Fun to drive. That's the up side.
Big thanks to Bruce Abbott for the engine and mike Lesniak (Dr. Evil) for the trans work including WaveTrac TBD install. Scott Burnett for the body and my friend Jim for all the help and encouragement when things didn"t go well. THANKS ALL.

[frosty2]

Beautiful car Gary and love the engine bay. Wondering what the block is you have the
Pressure gauge on. Is it a single inlet with the two outlets or do you have a return line.
I am thinking of adding the same gauge but I don’t have a return line and am having
trouble sourcing what I need.

Thanks
Mike

[gamin]

That block and gauge came from PMO. There is no return line from rear to front. Never had one. I am using the stock low pressure Bosch fuel pump which has 3 fittings, in, out, and return. The return comes out of the pump itself. And my pump is located in the smugglers box up front, a protected location that I like. I have read that a pump like the Pierburg which has 2 fittings in and out with no provision for return works just fine. Would probably have to block off the return inlet at the tank. Someone with more experience with that setup should comment.

[gamin]

In addition, I had my original Bosch fuel pump rebuilt by Fuel Injection Corp Livermore CA. They did a fantastic job and half the price of a new one. Even the packaging was class A.

[manbridge 74]

The basic wire strand does not deteriorate per se. The insulation can be torn from age, bad routing and failing to secure/protect. I see a LOT of these cars with dodgy wiring modifications.

A good point about lack of fuses on some circuits. Even with the key off there are several, still hot circuits at rear fuse panel (yes, the plastic cover that is missing from a lot of 911s has a purpose) etc. Grab a test light and poke around to find them.