Powder Coating Magnesium Die Castings

Question:

I have recently begun working with a new customer on both paint and powder coating of magnesium die-castings. This metal type is new to me and to others at my company. My main concern is the stripping and rework of coated parts that have been rejected. In an article dated 2/01/02, you outlined the four various methods but did not highlight which would work best for certain processes. Any help you can provide would be greatly appreciated. I have been searching the Internet with no real answers. S. W.

Answer:

Of all the stripping methods available for powder coated products, the ones that will work best for magnesium are chemical stripping and mechanical abrasion (grit blasting or sanding).

Whatever you do, do not use a burn-off oven!!! The ignition point of magnesium is well below the operating temperatures of these ovens. Furthermore, magnesium fires are particularly nasty. This means if you burn-off the powder coating on magnesium parts, the resultant fire will be particularly difficult to put out, since contacting burning magnesium with water will cause a violent explosion.