Super90

About to put another batch of new bits on the car and would love to get the fan housing looking like it was originally.

Is there a really good way to clean it and renew the finish?

If not, the next effort is to go with factory process and not powdercoat. I am reading in some previous posts that Porsche used an "anodic coating like Dow 17 followed by an organic coating or inorganic sealant".

How does one renew that finish/coating ? Who does work like that?

Pic of new fan and re-plated pulley halves and nut, just as a teaser:

993PET

I had the fan housing powder coated by Vehicle Craft in NJ, they came very close to matching the factory color and finish.

ToSi

The housing is bare magnesium AFAIK, and darkens over time. Yours looks 'correct' as-is.

slightly blurry photo but this is a new housing & fan:

993PET

Here is how mine looked with the fan and housing powder coated. This is after 5 years and 10k miles:

cscrogham

I have had some luck cleaning with a citrus solution and lightly soda blasting the housing, then rubbing it back up with a clean oily cloth. The trick is getting the black to come back out for an original look, the finish is not consistent so can't be replicated with paint or coatings.

Super90

The black chromate was supposedly treated with Tectyl (a corrosion preventative made by Valvoline) at the factory. I'm reading that was the process for quite some time and there are some friends that restore the early cars that have dealt with this too. Tectyl seems to be difficult to source in the U.S. now. I'm finding out via some sources that using another "oils" produces good results. The PO of my car, who does lots of restoration projects for himself, likes to use Gibbs Penetrating Oil on such magnesium parts. I had read about people using it on old "hot rods" on the mag wheels to give the nice dark gray patina. I'll try it on this application and report back.

Interestingly, this black chromated magnesium part is a bit of Porsche history.

cobalt

Sorry thought you had asked about the fan itself. AFAIK you are correct but I don't know what chemical conversion was used. The spec for Dow conversions would be MIL(AMS)-M-3171. I have a copy of both Mil and AMS specs someplace but I don't believe any will result in the same finish. Most will give a gray, green or gold coloring depending on alloy and temper.

Problem is some of these process caused health issues and are no longer used.

You might try contacting Valvoline and see if they have a product that will mimic the black.

http://petroleumservicecompany.com/t...FQhYDQodjmYPLw

You might try contacting Quality Metals here in NJ http://qualitymetalfinishing.net/

They do great work at reasonable pricing but sometimes have a long turnaround time.

Super90

I used the Gibbs oil. It looks like Kroil, but smells different and it seems to leave a finish on the parts that is waxy. I think my "freshening project" turned out well.

Earlydays

looking good!

Parman

Great job, what did you use to clean all the black rubber and plastic bits?

Super90

Vinylex by Lexol. I haven't even treated those parts with that in a while. They seem to stay clean.

ThomasC2

Let a lot of WD-40 work on the housing for a few days and it will get the right look.

cobalt

Looks great. It is amazing how simple things like a fresh sound deadening pad and fresh brightwork will make huge difference how the engine bay will look. I am in the process of having my engine tin all painted. I should have dropped the engine but replaced the pad with the engine in place. Just changing the pad alone was huge.

cscrogham

Looks great, well done!

no_car

great looking engine bay! that is in my todo list on my car to make the engine sparkle a bit!