# Can MAGNESIUM be Used To Make Cars? **URL:** \ **Category:** Factual Questions\ **Created:** [October 10, 2002, 1:45pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673 "2002-10-10T13:45:36Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [October 10, 2002, 6:40pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/21 "2002-10-10T18:40:31Z")
Another Magnesium drawback. Owned a _real_ Beetle back when the engine was made out of an alloy of it. The threads holding the two main blocks of the engine would wear out since they were **too soft**. The solution was to drill out the holes and put in harder inserts. Not cheap. ---
**Author:** ![racekarl](https://avatars.discourse-cdn.com/v4/letter/r/6bbea6/32.png) [@racekarl](https://boards.straightdope.com/u/racekarl)\ **Post date:** [October 10, 2002, 7:17pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/22 "2002-10-10T19:17:39Z")
A few things: Many race cars today feature magnesiumn parts, most notably the wheels of most open wheel race cars are made of magnesium. Also, the Audi you are thinking of is the A8 (and S8). Both feature an aluminum unit body chassis. The A6 features several aluminum bits, sunch as the suspension and hood. There is no such car as an A5 (or A-5). Audi had to invent several new methods of bonding aluminum in order to make these cars production feasible, and dealers and body shops must go through extensive trainging and equipment purchases to be able to service them. I would imagine similar new processes would be required for maenesium ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [October 11, 2002, 1:56pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/23 "2002-10-11T13:56:24Z")
I was at a customer site (a body stamping shop) a few years ago and compared three identical deck lids – don’t know if they were for a specific vehicle or not, or just models. One was bare steel (deck lids don’t need to be galvanized), one aluminum, and one magnesium. The magnesium was _incredibly_ light, to the point that I was in complete disbelief. I think this particular shop’s display was just to inducate that they were capable of stamping and spot welding all of those materials with no problems. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [October 11, 2002, 3:18pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/24 "2002-10-11T15:18:20Z")
[Magnesium alloys](http://www.immnet.com/articlelibrary/archive/getOneArticle.php3?getArtID=1418) have an ignition temperature of about 850 F (454 C) which is comparable to that of aluminum. In solid form with large volume they are hard to get started because heat is conducted away so rapidly that the temperature doesn’t get very high. If the whole article of either metal is in the flame then both will burn if oxygen is present. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 11, 2002, 3:27pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/25 "2002-10-11T15:27:53Z")
> [@](#): > > \*Originally posted by everton \* > \*\*My experience if based on chemistry lab experiments when small pieces of magnesium, sodium and potassium burnt very freely on contact with water and were kept under oil to stop it happening spontaneously. \*\* Not magnesium IIRC: Sodium + water = Fwoomp! Lithium + water = Fwoosh Potassium+ water = Fizzzz Magnesium + water = Not a lot. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 11, 2002, 3:29pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/26 "2002-10-11T15:29:50Z")
Sorry, I think I meant Calcium + water = fizzzz; can’t remember what potassium does. ---
**Author:** ![andy\_fl](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@andy\_fl](https://boards.straightdope.com/u/andy_fl)\ **Post date:** [October 11, 2002, 3:45pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/27 "2002-10-11T15:45:02Z")
> [@](#): > > \*Originally posted by flertbert \* > \*\* a magnesium engine caught fire and he had to stand there and spray water on it in hopes that it would keep the fire from spreading to the gas tank \*\* :smack: so much for fire fighters !! Next time you see a metallic fire (Magnesium, Sodium, etc.) **NEVER** try to PUT it out with Water. For all you know, your “firefighter” friend was feeding the fire. No need for hydrogen powered cars, your friend was generating some right there, adding water to hot magnesium 🙂 From this [MSDS Cite](http://www.acialloys.com/msds/mg.html) “Use only graphite powder, soda ash, powdered sodium chloride, or an appropriate metal-fire-extinguishing dry powder. Do NOT use water, carbon dioxide, or foam.” ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [October 11, 2002, 4:23pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/28 "2002-10-11T16:23:26Z")
potassium + water = explosion if potassium is big enough. Very dangerous ---
**Author:** ![Osip](https://avatars.discourse-cdn.com/v4/letter/o/4491bb/32.png) [@Osip](https://boards.straightdope.com/u/Osip)\ **Post date:** [October 11, 2002, 10:41pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/29 "2002-10-11T22:41:43Z")
Hey the M113 used it… from here…[http://www.vwip.org/articles/m113apc.htm](http://www.vwip.org/articles/m113apc.htm) The cold rolled alloy hull of the M113 was made from Aluminium, Manganese and Magnesium. It’s armour thickness varied from 3/4" to a maximum thickness of 1 1/4". This thickness provided protection from small arms fire and shell fragments, but would not stop a round from the soviet made RPG-7, or withstand the blast from a land mine. ---
**Author:** ![Wearia](https://avatars.discourse-cdn.com/v4/letter/w/13edae/32.png) [@Wearia](https://boards.straightdope.com/u/Wearia)\ **Post date:** [October 11, 2002, 11:04pm UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/30 "2002-10-11T23:04:05Z")
> [@](#): > > potassium + water = explosion if potassium is big enough. Very dangerous In smaller quantities it ignites and swims around until it is dissolves. Pretty neat to watch. But leave this experiment to the pros. If your not care you’ll inhale some fumes and the potassium with explode. In other words: Don’t try this at home. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [October 12, 2002, 2:41am UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/31 "2002-10-12T02:41:09Z")
You can use pure magnesium for an engine block without it catching on fire. The reason you only see alloys used is for strength and wear resistance, not to avoid fire. Large pieces of magnesium, or small, will not spontaneously combust in atmospheric air. Putting water on a magnesium fire borders seems…peculiar, regardless of what the end goal is. Magnesium has a fracture toughness that is similar to cast iron. ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [October 12, 2002, 4:28am UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/32 "2002-10-12T04:28:14Z")
> [@](#): > > \*Originally posted by RealityChuck \* > Yes, magnesium manufactured into a car does burn. > > Back in 1955, Mercedes ran a magenesium-bodied car at Le Mans, driven by Juan Fangio. It crashed into the stands and went up in a fireball. 85 people were killed, one of the worst spectator disasters on the Grand Prix circuit. Mercedes quit the circuit and I suspect magnesium was banned. Fangio was with the Mercedes team in 1955, but was only indirectly involved with the accident at Le Mans. The car that crashed was driven by Pierre Levegh. Fangio lived to be 84. Magnesium was seen again in Formula 1. Dan Gurney’s 1967 Eagle had a chassis and panels made of magnesium. His win at Belgium that year is still the only Formula 1 victory by an American driving an American car. ---
**Author:** ![red\_dragon60](https://avatars.discourse-cdn.com/v4/letter/r/ce73a5/32.png) [@red\_dragon60](https://boards.straightdope.com/u/red_dragon60)\ **Post date:** [October 12, 2002, 5:55am UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/33 "2002-10-12T05:55:31Z")
Aha! Mg will light in contact with air! It must be around 1000 degrees though to light it. Semantics people, semantics! ---
**Author:** ![flertbert](https://avatars.discourse-cdn.com/v4/letter/f/e5b9ba/32.png) [@flertbert](https://boards.straightdope.com/u/flertbert)\ **Post date:** [October 12, 2002, 6:03am UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/34 "2002-10-12T06:03:28Z")
> [@](#): > > \*Originally posted by andy\_fl \* > \*\* > :smack: so much for fire fighters !! Next time you see a metallic fire (Magnesium, Sodium, etc.) **NEVER** try to PUT it out with Water. For all you know, your “firefighter” friend was feeding the fire. No need for hydrogen powered cars, your friend was generating some right there, adding water to hot magnesium 🙂 > > From this [MSDS Cite](http://www.acialloys.com/msds/mg.html) “Use only graphite powder, soda ash, powdered sodium chloride, or an appropriate metal-fire-extinguishing dry powder. Do NOT use water, carbon dioxide, or foam.” \*\* Well, it’s been years since I talked to the guy and I may have misremembered some of the details. They may have simply hosed down the rest of the car, I know that they didn’t have the money for foam, it being a volunteer fireman gig and all in a rather small town. ---
**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\ **Post date:** [October 12, 2002, 9:50am UTC](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673/35 "2002-10-12T09:50:23Z")
> [@](#): > > \*Originally posted by racekarl \* > **Also, the Audi you are thinking of is the A8 (and S8). Both feature an aluminum unit body chassis. The A6 features several aluminum bits, sunch as the suspension and hood.** And the A2, A3/S3 and A4, which all, IIRC, have aluminium space frames. [Previous page](https://boards.straightdope.com/t/can-magnesium-be-used-to-make-cars/131673.md?page=1)