Magnesium Sheets Anyone?

[greygoos]

I have the opportunity to purchase 063 - 4 X 12 Magnesium sheets for 30.00 per sheet. They are new but are discolored or stained. Since I am getting ready to start my next build I was wondering what your thoughts might be? Thank you

[Shadow Catcher]

It burns very very well!

[yrock87]

In an accident that may be a bit of a liability. I believe magnesium ignites when struck on steel (flint and steel).

Having said that, bmw uses magnesium in their engine blocks to keep weight down...

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[yrock87]

In an accident that may be a bit of a liability. I believe magnesium ignites when struck on steel (flint and steel).

Having said that, bmw uses magnesium in their engine blocks to keep weight down...

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Op, I'm wrong. Flint is different. However it is used in some fire starter kits in conjunction with flint and steel as a tender.

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[greygoos]

From what I understand magnesium strips and powder are highly flammable. Magnesium in solid form is hard to ignite. I am glad I asked the question and now am reconsidering. If I get half as frustrated with this build as I did with the first one I might blow myself up. LOL

[dales133]

There was a fire where i work 2 years ago and the magnesium VW engine cases melted holes through the concrete 6 inches deep

[rowerwet]

Depending on the alloy, Magnesium is also highly reactive, road salt and acid rain could eat it away unless well primed and sealed.
Magnesium is often used in aircraft for sections that would be much heavier if made from steel or aluminum. I often find pitting in it from water getting into cracks. And as others have said, it burns really hot and bright, which is why it is one of the main parts of flares.

[MtnDon]

Depending on the alloy, Magnesium is also highly reactive, road salt and acid rain could eat it away unless well primed and sealed.

Oh yeah!! That reminded me that magnesium is used as a sacrificial anode in some hot water tanks. It is also used in boats and many industrial facilities that operate in wet environments. The magnesium corrodes away before other metals. Aluminum is also sometimes used as an anode but magnesium is approx twice as reactive. Moisture must be present so if you are in a desert it probably does not matter much.

Link to table with most likely to corrode metal at the top; magnesium

[Thelgord]

On another note, the hull, floor plating, and skin of a chinook helicopter is made entirely of magnesium. I also found this: http://www.totalmateria.com/Article35.htm

The tl;dr version:
It must be tig/mig welded and done quickly. Slower processes can actually weaken the metal around the joint, while the joint itself will remain strong. You must use gas (no flux core) as the slag that is produced by flux core can be corrosive to magnesium alloys. Visually there is no discoloration when welding, heating or cooling the metal and the only ways to test a weld is a "bend test" that ruins whatever you just welded or an x-ray.

It is a reactive metal, which means direct contact with other metals will start corrosion almost immediately. A coat of paint or other such coatings is required between different metal types. This is good to know if you use brackets and bolts rather than welds.

It's a great metal to work with, but there are some best practices rules when working with it.

[Jiminsav]

i think if you can get it, and it works for you, do it. it is highly corroded, but if you paint it with zinc chromate and then some real paint, should last a long time. and any steel screws that penetrate should also be drove in while zinc chromate is wet.

[Andrew Herrick]

At first, I was kinda incredulous ... but now I'm not so sure?

Now, if you're using 0.063 magnesium sheets you won't be saving much in weight compared to standard 0.032 or 0.040 aluminum. And besides, a 0.032 sheet of 4x12 aluminum weighs - what - 25 or 30 pounds? Magnesium is just 33% lighter than aluminum.

Preventing galvanic corrosion between the magnesium siding, the trailer frame, any aluminum trim, fasteners and brackets might be a hassle. ..

But if you can figure out a way to prevent galvanic and atmospheric corrosion (metal polish or paint), then for $30 for a 4x12, I don't know if I'd pass it up for a one-time build.

You should do it and tell us how it fares in 5 years