Color and finish for radiator fan

[rutger kohler]

I took my fan blade unit to the place that will gold passivate my other parts.  They said that the gold passivating does not work well on cast alumnium parts, and to have it powder coated so this is what I will do.

Many thanks for your comments

Rutger Kohler

[wwheeler]

This may be a dumb question, but what is passivating and does it differ from anodizing? I have never heard of passivating and am wondering if it is a term with a different name over here.

Kind of like boot vs. trunk

[mdsalemi]

Wallace,

No dumb questions.  Passivating is just one word to describe the application of metal-oxides using a variety of processes to a metal, to protect it.  Anodizing is one form of passivation.  If you google or wiki the terms, you'll come up with all kinds of companies that do the stuff and describe it.

Rutger, some of determined that the fan is magnesium not aluminum.

Different firms use different processes and some have better luck than others with different processes and substrates/materials.  Listen to the guy who is doing the work-if he says it won't work well for goodness sake don't force him to do it!!

[KevinC]

I just scanned this pic from my 230 SL brochure that I believe to be from 1966.

[twistedtree]

That's a great reference shot, and it shows how over-restored some cars are.  There's way less CAD plating than what I've seen on some.  That's also an older 230 than '66 I think, judging from the banjo fitting for the valve cover vent line rather than a rubber elbow.  According to EPC, the banjo was used up to manual motor 10787, and automatic motor 2991.  I'm not sure what years that corresponds to.

[rutger kohler]

Hi, thanks for all your comments, very helpful.  In the end I decided to spray paint my fan.  Rubbed it down and then used etch primer before giving it 4 or 5 coats of gold paint.  You can see the finish in the photo.  Still assembling the  engine bay.  I used POR15 Glisten satin finish on the vave cover, it is shinier than i would have liked.

[Jonny B]

Where did you find the clamps that you have on the hose that is under the thermostat housing?? I had a couple of those on the 280 SL, but they were in pretty sad shape, so I replaced them with the Norma clamps.

[rutger kohler]

Hi Jonny, when I took the parts I wanted gold passivated, to the platers, I also took all the old hose clamps back and got them replated (zinc).  I opened them up first and cleaned them on a wire brush wheel attached to a bench grinder.  i was surprised how well they all turned out.  I am short of some though and I will have to use Norma ones too.

[Jonny B]

Thanks for the update. I did save the ones I had but had not tried any further cleaning/etc. I replaced all the clamps with the Norma style so it at least looks consistent.