Author Topic: Color and finish for radiator fan (Read 17917 times)

rutger kohler · « **on:** January 06, 2012, 07:22:21 »

Hi, I am tidying up the engine bay on a 1969 280SL. Have been advised that generally the parts in the engine bay are painted black, satin finish, however the radiator fan blases look like they are a brass color. Is this orignal or should they be satin black too?

Garry · « **Reply #1 on:** January 06, 2012, 08:58:24 »

My 69 fan blades are satin black. I believed that was the correct colour. I am about to be proved wrong.

49er · « **Reply #2 on:** January 06, 2012, 17:06:31 »

Here is a picture of my 6 month old 280 SL engine bay taken back in 1969. The fan blades are anodized, not painted.

John

rutger kohler · « **Reply #3 on:** January 06, 2012, 19:51:34 »

Hi, thanks to both of you, looks like mine was gold passivated then. Nice looking enginebay John!

49er · « **Reply #4 on:** January 06, 2012, 22:34:12 »

Thanks Rutger,
Wish I had taken more pictures of the car back then, especially the engine bay. The Castrol sticker was put on by the dealer and the clutch reservoir cap had cracked (electrical tape holding it on in the photo) and it was on order when this picture was taken. Still looks pretty the same today but all the plating has faded away and the hose clamps have all been replaced. Gold passivated or gold anodized for sure:-)

John

Nate · « **Reply #5 on:** January 08, 2012, 03:55:28 »

Virginal engine bay. Very nice, and nice to see that Castrol was the reccomended engine oil back in '69 and still is today.

douglas dees · « **Reply #6 on:** January 09, 2012, 03:10:32 »

I understood that all fan blades were a natural alloy colour except the Geneva/ New York show cars that were painted red to show off the engine compartment. My detailer did mine in yellow which looks cool until they get dirty.
Doug Dees

49er · « **Reply #7 on:** January 09, 2012, 04:14:32 »

Hi Doug, Yellow! That must be a chore to keep the blades shiney:-)
Here is another photo taken of my late departed 250SL engine taken a few weeks after I brought it home (May 1967). The blades also apear to be of "golden" color. Not sure what the alloy is but definitely not painted. We went for a drive up to Apple Hill a few days ago and Camino still looks the same as I am sure your sister can attest too:-)

John

rutger kohler · « **Reply #8 on:** January 09, 2012, 07:54:49 »

All very interesting, I have got the fanblade unit off now so will have a look and see how deep the color goes. As one of you says, the fan gets dirty quite quickly, and they have a failrly rough surface so may not pay to put too much effort into it?

zoegrlh · « **Reply #9 on:** January 09, 2012, 15:23:04 »

I saw Michael Salemi's Fan a while back. He did his in silver power coat. What a great looking fan. I am going to do this to my fan as my winter project this year.
Bob

wwheeler · « **Reply #10 on:** January 09, 2012, 21:26:42 »

I don't know if the W111 fans were different, but when I took mine off, I only saw bare aluminum. The yellow could have worn off though. But I didn't see any even in the recesses where the clutch mounts. Not sure why they would have gone to that extra step of anodizing the fan?

Like Michael, I powder coated mine with Bengal silver. It is brand new in the picture and looks like freshly prepped cast aluminum. While I was there, I also did the distributor mount, the alternator pulley and thermostat housing.

rutger kohler · « **Reply #11 on:** January 10, 2012, 06:52:46 »

Hi, as mentioned I looked more closely at my fan blades today. The casting is definitely aluminium and I can see gold passivationg under the bolts that hold the blades on. I like the idea of powder coating it. Had thought about tidying up the casting for the distributor drive but the engine runs really well now and I don't want to up set the timing so will probably leave.

Bengal silver job looks really good too!

cheers

Rutger Kohler

georgem · « **Reply #12 on:** January 10, 2012, 12:09:18 »

Uh oh...... with all this talk of anodised aluminium and powdercoating, how does my 230sl with a 4 bladed nylon (yellowish) fan fit into the scheme of things or have I now detected a non standard item on my car?

George

jacovdw · « **Reply #13 on:** January 10, 2012, 13:16:30 »

George,

The current replacement fan from Mercedes for the 230SL is the 4 bladed nylon one you have.
Originally (for the 230SL) the fan was made from metal and painted black.

mdsalemi · « **Reply #14 on:** January 10, 2012, 13:29:01 »

Quote from: zoegrlh on January 09, 2012, 15:23:04

I saw Michael Salemi's Fan a while back. He did his in silver power coat. What a great looking fan. I am going to do this to my fan as my winter project this year.
Bob

Yes, just prior to PUB this year I replaced the radiator and water pump. ALL the parts that had to come out to access these parts, were powder coated prior to reinstallation. This was the fan shroud, the battery tray, the air cleaner components, and the fan.

I chose a heavy glossy silver so it would be easy to clean. The blades of the aluminum fan in their raw state are quite coarse in texture, which is a magnet for dust, dirt, grease and all manner of discoloration. Now, a simple wipe of a cloth and the fan is clean.

thelews · « **Reply #15 on:** January 10, 2012, 14:47:01 »

I got my cr in 2007. I don't think I've ever touched the fan blade. Is this considered an unacceptable condition? Sometimes treated parts take on an "unnatural" look.

66andBlue · « **Reply #16 on:** January 10, 2012, 18:00:14 »

John,
here is a comment about the fan blades in your car from the PO:
http://www.sl113.org/forums/index.php?topic=2768.msg15635#msg15635

These fan blades are made from a magnesium alloy not aluminum! See also reply #2 from Joe A.
~~Why they should have been "yellow/gold" is a mystery to me.~~

49er · « **Reply #17 on:** January 10, 2012, 18:15:02 »

Alfred, thanks for your reference to Joe's post on this matter. I apologize if I got some folks onto the wrong track by thinking the blades were "anodized aluminum". The only thing I am pretty sure about is the fan's color when the car was new. All the color has now disappeared over the years and the blades are just a dirty grey now.

John

thelews · « **Reply #18 on:** January 10, 2012, 18:46:02 »

Quote from: 66andBlue on January 10, 2012, 18:00:14

John,
here is a comment about the fan blades in your car from the PO:
http://www.sl113.org/forums/index.php?topic=2768.msg15635#msg15635

These fan blades are made from a magnesium alloy not aluminum! See also reply #2 from Joe A.
Why they should have been "yellow/gold" is a mystery to me.

Vince was a great keeper of the car. And, I even have the P21S Total Wash to clean it with per his suggestion! Should I need to clean it.

mdsalemi · « **Reply #19 on:** January 10, 2012, 19:42:52 »

Based upon the photos of thelews, I suspect when my fan was "originally" restored back 10 years ago, somebody media blasted it and mine took on an extremely rough texture, like 60-grit sandpaper! John's (thelews) looks quite smooth. The rough texture, like all textures, is a bit harder to keep clean than smooth. Short of replacing the fan, the powder coat brought the texture back to smooth and the color "fresh"--this is with the full comprehension that it isn't correct or original.

georgem · « **Reply #20 on:** January 10, 2012, 20:11:57 »

Quote from: jacovdw on January 10, 2012, 13:16:30

George,

The current replacement fan from Mercedes for the 230SL is the 4 bladed nylon one you have.
Originally (for the 230SL) the fan was made from metal and painted black.

Jaco,

Thanks for the info. It begs the question re efficiency of the fan with less blades than the original metal fans. Although I`ve never had any problems with cooling, I wonder if an original metal 6(?) bladed fan would be better. I wonder if the change was noise related?

Cheers

George

66andBlue · « **Reply #21 on:** January 10, 2012, 20:27:32 »

Quote from: 49er on January 10, 2012, 18:15:02

Alfred, thanks for your reference to Joe's post on this matter. I apologize if I got some folks onto the wrong track by thinking the blades were "anodized aluminum". The only thing I am pretty sure about is the fan's color when the car was new. All the color has now disappeared over the years and the blades are just a dirty grey now.
John

Hi John,
I am sorry too - I did the same. The discussion between JA17 and Tom230SL concerned the 4-blade fan in a 230SL that was magnesium and then Vince mentioned that the (6-blade) fan in his 250SL is also magnesium. This may not be correct for fans on 280SLs - I changed my previous post.
I know of a NOS fan that Dave Gallon has for a 280SL and it has the yellowish/gold coating that you mentioned. I'll try to get a photo next time I see him.
Perhaps Mercedes decided to coat the magnesium/or aluminum for more protection?

wwheeler · « **Reply #22 on:** January 10, 2012, 21:00:10 »

Short of doing a materials test, how would one know that a material is magnesium verus aluminum? They are both lightweight and have a silvery/white natural color. I am not suggesting that the fan isn't magnesium but curious how you would know. If you can't anodize magnesium, what process would you use to get the yellow color?

mdsalemi · « **Reply #23 on:** January 10, 2012, 21:09:13 »

Quote from: wwheeler on January 10, 2012, 21:00:10

Short of doing a materials test, how would one know that a material is magnesium verus aluminum? They are both lightweight and have a silvery/white natural color. I am not suggesting that the fan isn't magnesium but curious how you would know. If you can't anodize magnesium, what process would you use to get the yellow color?

Good question about aluminum vs. magnesium. I believe magnesium is easier to cast, but just a guess.

The coating is an easy one. It is yellow chromate, typically something like Alodine (look that one up yourself!) Used to provide a better base for painting (not so in this case) or for corrosion protection. The generic term would be hexavalent chromium, and it is used on aluminum and magnesium. Magnesium is subject to corrosion with salt solutions, more so than aluminum. It's a constant battle to protect magnesium components in the aircraft industry, so my guess is MB put the coating on the fan to protect it. Again, just a guess...

49er · « **Reply #24 on:** January 10, 2012, 23:37:16 »

I have owned this car for 43+ years and I learn something new about it everyday on this forum. Many thanks guys!

John

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Author Topic: Color and finish for radiator fan (Read 17917 times)

douglas dees

jacovdw