Thoughts on Fan Finishes

[lucittm]

Hello All,
I have seen a variety of finishes on our cooling fans. Everything from polished aluminum to powder-coat. Is there a consensus which is best or is it just a matter of taste?

Is there a weight advantage to having no coating at all?

This discussion is prompted by the peeling factory coating on my fan. Is this a common problem? Should I remove it? What is the best way to take it off?



Thanks,
Mark

[88911coupe]

From what I can see in your pic you're not looking at the factory finish...that looks like paint or something. I'd think paint remover would make pretty short work of that. From prior posts painting tends to be hit or miss, depending on prep and other factors. The housing looks to be pretty clean, at least compared to what mine looked like!
...edit, just noticed it looks like you've upgraded to a serpentine belt...how's that working for you?

[OldTee]

Mine.

[Facey]

that is a cool combo i have never seen!

i have a secret one coming next time mine comes off (this x-mas maybe)...

N

[afterburn 549]

Base coat clear coat works just fine for me !!

[al lkosmal]

I've had the best luck with powder coating. This pic is after approximately 2 years of use on two different engines.

[Flieger]

Remember, powder coating is thick, so tell the coater not to coat the tips of the blades and part of the inside of the housing; otherwise you will have interference issues due to the precision clearance between the fan and housing for maximum flow efficiency.

I would polish and just let it oxidize. Even powder coating will not stop Magnesium from oxidizing. It just slows it down and makes it harder to see.

Any coating will need to be refreshed often in order to retain the "like new" finish.

[JohnJL]

Powder coating is the only thing that lasts for any measure of time.

I wouldnt bother giving the powdercoater any special instructions, you might end up with a splotchy coat, not doing the front or something else silly. 2 minutes with some sandpaper will remove the powdercoat from the tips. That does the trick.

Also, mag does corrode but this is only an aesthetic fix. Ive never heard of anyones fan oxidizing into powder...maybe another 300 years...

[al lkosmal]

No special instructions, just powder coat and go. Tip sanding may be required, but leaving the housing partially coated was not required (as you can see in this photo). No big deal and lasts a long time.

[Schwarzeritter]

Do be perfectly honest, in my own experince I have to say that it really does play into
the individual who is preforming the powdercoating. I have had some very excellent beautiful
work done and some that were very sketchy.

Typically I have never had a problem as over the
years I have found individuals or companys here in California who provide a good service and
we have a good company to company business relationship.

I have not had any issues or problems with cooling or too much paint being applied,
with a Porsche platform. I think also the paint to clear coat ratio is perhaps important.

^_^

[OldTee]

My daughters 87. Works for her.

[WERK I]

I think when it's time for replacement of the mag pieces, I'm going for the aluminum reproduction pieces ( that is, if the quality control is there ), have them anodized and be done with it. Anodizing is low-maintenance and it's damn near bullet-proof. I've got better things to do other than spending 4 hours polishing a fan/housing.

[afterburn 549]

[QUOTE=JohnJL;4344700]Powder coating is the only thing that lasts for any measure of time. End of Quote.
Not sure what you base your authority on........but in my case you are wrong,

What is your measurement of "time" ?
Mine is base coat clear coat, been at least 5 years..did it my self ( as the rest of the car ) Looks great, and still purrrrfect !! Best part is did not cost me a arm and leg as I did it same color as the car with (left over ).
So........I would not discourage this route at all

[Rot 911]

I used Kmart Krylon paint on my fan. 20,000 miles later and it still looks good.

[coxy]

[QUOTE=lucittm;4339663]Hello All,
I have seen a variety of finishes on our cooling fans. Everything from polished aluminum to powder-coat. Is there a consensus which is best or is it just a matter of taste?

Lots of options to go with, its up to you.

[lucittm]

88911coupe,
I should have tried some paint remover when the engine was apart. Don't most of them say not for use on aluminum though?
As far as I know my fan is stock. The serpentine belt came standard on the turbo cars. I do like the polished and clear coat option. I believe that form follows function and the purpose is for the fan to move air and not induce drag due to a rough or irregular surface. Also, the powder coat has to add some weight. I wonder how much and would it affect the balance?

Thanks,
Mark

[88911coupe]

Mark, I'm pretty sure it's magnesium, although you bring up a good point about paint remover. It may not be good for magnesium either. I'm sure some of the metalurgists/chemists can enlighten us on this issue.

[chris_seven]

Powder coating is a broad generalisation and depending on the material being applied it may last quite well of fall off after a realtively short time.

I think that the best 'powder coating' for magnesium or aluminium used in an engine bay would be to use a proprietary nylon such as Rilsan.

Magnesium parts should be chromated before coating as this will ensure good adhesion and give excellent protection.

Aluminium could be pre-treated with either an Alobrite1000 or Alobrite1200 which is a slightly different chromate treatment.

Nylon is good because it is oil, petrol and brake fluid resistant.

Coatings can be either electrostatically sprayed or dipped using a fluidised bed.

[lucittm]

coxy,
Is that your engine? It is a work of art. Can you enlighten us on how you made those pieces so shiney? Is there some chrome plating involved? What finish did you apply to the fan? I see that the air valve is polished, did you seal it with a clear coat? How about those hose clamps...

Mark

[teamfee3]

I wish I went with the matte gold finish.