Powder Painting Magnesium

[rs6er]

I am detailing my motor during a rebuild. My mechanic said that the fan and housing are not good candiddates for power coating because of offgassing in the heat phase. Has anyone heard this, and if so, what is good paint for these parts?

[A930Rocket]

I would media blast them and then powdercoat them. People have been doing them for years. If you chemically strip it, then it might offgas. Just make sure you don't spray too much on as your fan might rub on the fan housing. If it does, you'll have to sand the fan blades down a hair and re-powdercoat. BTDT.

[NY65912]

5 bead blasted my fan and housing first, then had them clear powder coated. After two years they still look new.

[tctnd]

Outgassing can be a concern with porous castings, especially used parts that have soaked up some oil, but the solution is easy. After the part is prepped but before coating just bake it for a while at the powder cure temp (usually around 425F) then let it cool and coat in the normal way.
regards,
Phil

[rs6er]

Originally posted by tctnd
Outgassing can be a concern with porous castings, especially used parts that have soaked up some oil, but the solution is easy. After the part is prepped but before coating just bake it for a while at the powder cure temp (usually around 425F) then let it cool and coat in the normal way.
regards,
Phil

The parts are at the bead blaster now. Can I bake them in my kitchen oven as you described before taking them to the powder coater? How long should I bake them?

[CurtEgerer]

You might want to forego any coating and return it to its factory look by simply using Gibbs miracle juice:

http://www.roadsters.com/gibbs/

[rw7810]

John - Let me guess, you're not married?? Ha!

[Paul Ferradas]

What does it typically cost to powder coat a fan and housing?

[TxSquash]

Curt
What did you do to that fan and engine? It's the best I've seen. Give us detail.. details. Did you bead blast before? Tell us about that "juice". How long has that finish lasted,... what's the maintance?
thanks,
Doug

[tctnd]

You could do it at home if you plan to never use the oven again, but it's easier to simply ask the coater to do a pre-bake.
Back when I owned a powder coating shop this was SOP for any suspect parts.
regards,
Phil

[rs6er]

Originally posted by rw7810
John - Let me guess, you're not married?? Ha!

Wrong! Plenty married but no scientist. We baked my son's WRX headlights in the oven to get them apart (only at 250 degrees.) I wasn't sure whether or not much toxic gas or otherwise would be emitted by baking a piece of clean metal at 425 degrees.

[CurtEgerer]

Doug - the fan/housing were dipped in a hot degreasing tank for transmissions, etc. Then it was saturated with Gibbs penetrating oil. The link to that website I provided gives some good info/testimonials as to the effectiveness of this stuff. It's only been a couple of months, so we'll see how it goes. -- Curt

[deshetlr]

Curt that is the first fan assembly I have seen that has a true Porsche look to it. Did you try it on the transmission, engine case, etc?

[Quicksilver]

Originally posted by rs6er
The parts are at the bead blaster now. Can I bake them in my kitchen oven as you described before taking them to the powder coater? How long should I bake them?

Make sure you tell the powder coater that the fan needs to be hung flat while it is baking. If you hang it vertically the flow of the powder will cause the coating to vary depending on the orientation of the blades.

You won't be able to see any of this but the difference is enough that it can cause a resonance in the airflow that you can hear. Hanging it flat insures that any flow while curing is evenly distributed.

[Porsche_monkey]

Originally posted by CurtEgerer
You might want to forego any coating and return it to its factory look by simply using Gibbs miracle juice:

http://www.roadsters.com/gibbs/

Hijack - is the Gibbs stuff that good?

[rw7810]

Here is what Gibbs did to my fan after about 6 months. Very even light magnesium gray. The fan came out great, the housing has some pits, so I might just paint it black.