PostVW

The engine-fan-cover (aluminum) does not look the way it was 24 years ago.
How do I get the "like-new" look back? I donīt mean it should shine, it shall just be as it was when new.

red911 Targa

Hi PostVW:

I used increasing grit sandpaper. Started at 600 to 1000, to 1500, to 2000
then polished with aluminum polish. You may not want as shiny, or bright fan and fan housing as I got.

Tom

red911 Targa

Also, if you want to see how to buff, go to Caswell Plating's website and you can download their buffing guide.

www.caswellplating.com
www.caswellplating.com/buffs/buffman.htm

Tom

robert944h

I just typically sandblast them and shoot them with a clearcoat. It doesn't really look factory, buts looks good.

VA911

Looks tops Tom. Congrats

pjc

Cleaned and laquered.

PJC

dugsud

Is it an easy job to remove them for refinishing?

theiceman

Depends on your level of technical ability. I found it rather easy but it might be open to interpretation. You have to take off the igntion coil , a few bolts, tip the assembly forward , take the shroud off the back of the alternator .. disconnect the alternator wires, remove from car , remove alternator and fan assembly ...... was that easy ?

it is a litle bit of work but definitely dooable by your average car dude... there may be a few threads on this already. I took the opportunity to refurb my alternator also.

autobonrun

I ended up polishing my fan but powder coating my fan cowling. There are several things to look out for. One, the paint can't be too thick or the fan tips can rub. Secondly, the fan is made of magnesium, with the exception of the center section so you have to be careful of the material you use to polish it. Also, magnesium will not hold its shine indefinitely. It tends to get an oxidized patina after 4-6 months. I repolish mine now about twice a year. Several years ago, I sent an email to the engineering department of a magnesium manufacturer concerning how to get a long term finish. I've attached their response below and a couple shots of my fan/housing. If you can get a good paint job on the fan, you eliminate the need to repolish. While I was at it, I used some high temp paint on the heater hoses as well to dress up the engine compartment a little.

*Email response *

The short answer to your inquiry is that there is nothing I know that will give you that “polished look” on magnesium for the long term. This is the same issue people have for polished magnesium wheels. If you “polish” magnesium and simply apply a clear coat, the clear coat will delaminate (turn milky) from the magnesium at sharp edges and stone damage sites in even quite mild (humid/wet) conditions. This is because of the following factors –

Polishing with certain abrasives can contaminate a magnesium surface with cathodic (iron containing) impurities. This has the effect of further increasing the corrosion rate of magnesium alloys and aggravates the situation. Safe polishing media for magnesium would be high purity aluminum oxide, silicon carbide, glass or diamond. Do not use emery powder. Never use a wire brush to “clean” magnesium components.
Magnesium is an alkali metal and requires a conversion coating to be applied before painting. The conversion coating will passivate the magnesium surface and improve paint adhesion. This will slow or prevent delamination of the paint under corrosive conditions. All the best conversion coatings for magnesium are colored and most contain chromates. The “best” available conversion coating that would maintain a “shinny” finish is known as the # 21 Chemical Treatment (If you send me a fax number I can copy you with the chemical formulation which does contain hexavalent chrome compounds).
Magnesium is an alkali metal and epoxy based paints are preferred. Epoxy based paints suffer from UV degradation so should not be used as a top coat. Its probable best to apply a clear epoxy primer followed by a clear polyurethane for the look you are after. Cellulose paints on magnesium behave poorly.
Don’t know if this will help you – why not chromate the fan assembly using one of the better chromate treatments, rinse, dry the chromate film between 110 to 120 C, then apply a silver base/clear coat system.

magg

hello there,
I wonder why don't you use sometime magnesium ,not aluminum? I work in a company (Magnesium com ) which use magnesium metal for its products and business. I have seen one really good magnesium wheel .

europeancarmag

like stated above I really like the look of a sandblasted fan shroud. I blasted mine and had the fan powder coated. The red fan doesn't look very stock the but the shroud looks like it did from the factory.