What are the best methods for painting magnesium??

please dont paint your tranny

thanks
AA

Mag is pretty reactive to oxygen so you need a good paint. Most mag is 'pickled" which is kind of like an anodize or alodine coating for aluminum. It's a nasty process using acids.

I dug into into my magnesium design manuals and they recommended zinc paints. I used that 2 part self etching Dupont Variprime primer that sets up like a rock, (contains zinc), and hit the baby pop tan color with a coat of silver. Figure it better be hard to withstand rock chips and abrasions.

That AAron guy must be into tranny "bling".

AAron, mag corrodes, steel corrodes, and the corrosion is ugly in both cases. Mag is dark gray, and steel is rust red. Is your tranny grey and your car rusty red o great avoider of protective coatings?

Ken

Nope no tranny painting,,, just want to paint the fan shroud.

i used a basic automotive primer and paint over my fan shroud.,,,,


painted trannies do wierd things.....

Besides most trannys have a thick coating of petrolium based anti corrosive

built up on them....don't want to mess that up.

what kind of weird things?

hmmm...
haven't heard this.
my race shop recommend that I paint my tranny due to corrosion.

he builds tons of trannys for hot sand rails and those guys strongly believe in painting..

should be better than corrosion at a minimum, and we discussed the theory of shedding heat too.

brant

After assemblying the engine with powdercoated tin the the fan schroud looked pretty crappy. So on a whim I gave it a shot of Cast Blast. Had already used it on the intake runners. Guy at the paint store said it was suppose to hold up real well on intake manifolds and heads. It's made by Seymour. Have only put a few miles on the car but looks good so far.

This is what Top Fuel and Funny Car Teams use.

The Dow Chemical Company invented Dow 17, the first anodized magnesium coating, in the mid-1940's. At that time, Dow Chemical Company was the world's largest producer of magnesium. Dow 17 can be applied with either alternating or direct current. The electrolyte used to apply the coating is comprised of sodium dichromate, ammonium acid fluoride and phosphoric acid. The electrolyte has a pH of approximately 5 and should be operated at or above 160o F. The coating has little or no inherent salt spray resistance. On test plates made from alloys such as ZE41A, corrosion sites can be seen in as little as 48 hours. Dow 17 does provide good paint adhesion with the exception of migration from a scribe in salt spray. Corrosion can easily migrate in the very porous Dow 17 structure, even tunneling under the paint.

The Dow 17 coating can be applied as thin as 0.20 mil or as thick as 3.0 mil. The color of the Dow 17 coating varies between light and dark green depending upon coating thickness.

Good luck,

Dan

I painted my fan shroud about 4 years ago, and it still looks great. You can see it in the paddock, track car pictures, middle of page 5.
I used some Glasurit epoxy primer- 801-1552, some old shit silver basecoat we had laying around, and Glasurit clear. I'm sure any epoxy or self etching primer will work well, Zinc Chromate might work, but I've never had any good luck with that crap. Other people swear by it but I think epoxy is better.

Anybody ever try Gibbs Brand? Sounds like snake oil but I like the look.

Damn. "Reverses the effects" of rust and corrosion? Sounds like you could remove the upholstry and dip the whole car and it would be new again. It sure does sound too good to be true but hey, hope against hope at $20 a can.

Actually that's what he charges but if you google around you can find it a little cheaper. Pricing is about equal to what I paid for Kroil but you're going to go through a lot more of this stuff if you hose the pieces down like they say.

Not affiliated, never used the stuff, just curious.

just for AARON A GA O V ZA

stock /6 gearing no?

whats with the paint...

did someone say paint?

no paint ,its powdercoaded ,und yes all six gears

i think bondo powdercoated his and it warped IIRC.....

i guess that puts an end to that myth.....

but basically it now has a blanket on it and cant shed heat as well no?

So there are 2 theories to the debate about the "blanket" or insulation.

The antidotal that convinced me to try it over a cosmoline type coating was that radiators fins are painted black and not left as bare metal. This even when there is no chance of rust.. ie: aluminum fins often are painted also.

we debated about using silver or black and which would shed heat more until the radiator arguement came up.

no proof that is good or bad yet..

brant

Jim,

I used a "good" rattlecan on the housing for my 1.8. It went on perfect and looked brand new even after the engine was finally pulled. There are some pics in my blog, I think.

MW

as long as you're painting, may as well make it yellow, and make your car faster

Its done,, I used a self etching primer, then sprayed it with a cast coat containing ceramic. It turned out well. We'll see how long the paint last.

another

Last one

Sitting on its new home

pretty

What about cleaning said magnesium? I would like to blast my trans with some kind of abrasive and was thinking of using corn cobb since it's easy to get.

Anyone? Mueller? Bueller? Foley?

Second Jonwatts question.... what about walnut shells? I also want to clean up a tranny case, which looks almost like it's got small barnicles growing on it! Brownish/gray very rough "textured" surface around the bellhousing and other parts of the case.
2nd question: better to do any blasting/cleaning before or after tear-down? Before, everything is pretty much sealed up ALA you don't get too heavy handed around the sealed areas and the vent is good and sealed up. But with an empty case, you'll likely get the blast medium in every nook and cranny inside. Even with thorough cleaning you'll be wondering if you got it all out.