Mag wheel recoating???

Hi All
What's the best way to crack test, glass bead and recoating older Magnesium wheels? Powder coat looks good but hides cracks. What's the gold coating process that new mag wheels come with? Any good sources?
Thanks Wes

Wes, You should be able to get the wheels crack checked at a proper FAA facility. I imagine there are other sources for testing as well. As far as the coating/finishing is concerned I use the DP90 primer on bare mag. This is a satin black; there are other colrs available in the DP series. I learned about that from a CART team a number of years ago and have had very good luck with it over the years. In fact, I have never had to refinish a wheel. I have destoryed a few, but the finish remained!

Good luck.

Any blast cleaning should be done with new - not recycled - glass beads, baking soda, etc. Recycled media will impregnate the magnesium with whatever was blasted before, which will most likely cause premature corrosion.

Hey thanks guys! I scored three wheels today, to give me six wheels total of magnesium American Racers for my Eagle project!

Blasting any surface for the purpose of crack is contrary to the basic goal of the inspection. Blasting, weather walnut shell or steel beads, can peen over a crack rendering your inspection useless. Softer metals like magnesium and aluminum are particularly vulnerable to this. The crack could be covered and give you a false negative visual or penetrate inspection. Same goes for any abrasive (sanding) removal process.

Richard is correct that any blast media should be virgin material to avoid dissimilar metal contamination and the resulting corrosion. Most blast operators do not relaize how important this is. Ever had rusting on stainless steel? The blast media was probably used on ferrous steel prior to the stainless. Magnesium is especially susceptible to dissimilar metals corrosion.

Also, NEVER use a passivation system (Alodine, Iridite, etc) designed for aluminum on magnesium either. It will eat the magnesium and eventually destroy it.

If you use an FAA approved repair station they will be (or should be) well aware of these issue and treat your parts properly.

polish 'em. They're a PITA to take care of, but look freakin fabulous!