Mahle "Gas Burner" rims Bead blast and powdercoat, anything else ?

[southbay356]

Hi

I have a set of old Mahle gasburners that I would like to do up,

I was planning on getting them bead blasted and then powdercoated ,

Since they are real "mag" do I need to do anything else compared to doing an aluminum rim ?

And is the color the same as Mercedes wheels ?

Thanks for your advise

Dave

[Tom F.]

I would do some research before blasting magnesium with glass beads. It might be too aggressive. Baking soda, corn cobs or walnut shells all seem preferable, to me.

[classic]

Soda blast, and ensure that your powder coater knows that they are magnesium as they will need to be out gassed before coating.

[davep]

They have a special primer layer which was blue originally. I agree with soda blasting, but walnut shell might be okay.

[southbay356]

Since Mahle made these before powdercoating was used did they just paint them silver and then clear ?

I talked to the powdercoater and he was concerned that when tires were put on it would scratch the powdercoat and then moisture would get under it,

But then painting would do the same thing , so I am still confused

[912-2.8]

Magnesium parts typically, especially for structural components, have a surface treatment. DOW 7, DOW 17, HAE, and taginite come first to mind. The first two are like 1940s old. HAE was 60s, IIRC. Tagnite is the latest, toughest, and best salt corrosion resistant being a surface conversion to magnesium oxide. basically, youve wrapped your mag in ceramic armor .

DOW 7 is the 'wimpiest' but it makes a great paint adhesion base and you can do it at home for about $150 from chemical supermarket dot com. The others you'll have to have done professionally.

The nice thing about these coatings is they are fairly non porous so degassing (bake out) before painting usually isn't necessary.

What ever media you do use, make sure its 'metal free'. Even a small percentage of iron and the like left behind on the surface will yield nasty galvanic corrosion. So check your glass bead material as well as your soda. The 5xxx series of aluminum is the least reactive with most cast magnesium.

t

[Jens]

I've heard of using Vaseline or Gibbs on magnesium wheels and fan blades. I've never used either, but does someone with a giant brain know about this practice?

Only someone with a degree (masters, doctorate, or even a B.S. in B.S.) would be qualified to answer this question.

[boba]

I have a BS in BS as Jens has indicated and have used Gibbs on a mag fan. Was soda blasted to clean, washed and dried, then sprayed with Gibbs. Looks great after 2 years. For wheels you might have to re-spray periodically.

[Jens]

Thanks Bob. I'm guessing it soaks into the magnesium and seals out water and other caustic materials to prevent corrosion. The color becomes a dark gray, right?

[super9064]

I think it would be best to "restore" them to original. Powder coating them would lower their value to someone looking for the correct wheel for their car.