Magnesium is beautiful.
If brightly polished aluminum resembles chrome plating, polished magnesium is more like nickel plating, with just a hint of gold to it. No other metal looks like it. Magnesium that has been brightly polished is unique and striking.
Magnesium is strange stuff.
After you polish it to a beautiful mirror finish, as time passes it will gradually turn gray, and then dark gray, with a bit of green.
Magnesium is extremely difficult to weld.
Generally speaking, the more someone knows about welding, the less likely they are to want to have anything to do with repairing magnesium castings.
Magnesium is dangerous.
If it ever catches fire, throw a bucket of sand on it and run for your life. When magnesium burns, it virtually can't be stopped. Small quantities of magnesium are used to make photoflash bulbs. Larger quantities are used to make bombs.
Magnesium is exotic.
In the world of vintage race car parts, there is no other metal that is so tough to deal with. But many of the most desirable drag racing parts were made out of magnesium, including blower housings, end plates, manifolds, and pulleys, fuel filters, fuel injectors, late Hemi timing covers, oil pans and valve covers, Ford and Olds differentials, quick-change rear end center sections and covers, and some really neat wheels.
Magnesium is a pain.
But its use plays an important role in hot rodding, and we deal with it.
The biggest challenge in taking care of magnesium parts is preserving them. With exposure to humidity, magnesium oxidizes, and tiny craters that are commonly called pits are formed. When magnesium parts are left unprotected and exposed to moisture, these pits eventually can grow to over an eighth of an inch in diameter.
I've seen a pair of magnesium racing wheels that were left lying outside in a field for many years. They had craters as big as three-eighths of an inch across all over them.
The twelve-spoke wheel pictured below is on an old Willys Altered that has sat outside for several decades.
This stuff is alive.