What DB might have done without budget limits on the Pagoda project.

[Tomnistuff]

I was trying to find information about proper plating of parts on the SLs (for my restoration) and found the link below.  I thought at first it was over the top, but on a black car, that gold CAD really grabs me.  The next time I get sick, I may call these guys to do my surgury.

Now I am really confused about what`s supposed to be gold CAD and what`s not.

Can someone point me to a set of photos that are cosmetically correct for a late 230SL?

http://www.facebook.com/media/set/?set=a.10150595892289294.404507.248013974293&type=1

Tom Kizer

[Garry]

Tom,

I have just finished doing all the cad plating in the engine bay on mine. Here are some photos

[Benz Dr.]

Almost all of the metal hardware in the engine bay is yellow cad but there are some pieces that are silver or clear. There are also a smaller number of pieces which are painted black or are bare aluminium aside from the main castings.
Some nuts are hit with a yellow paint stick and I've also seen green paint in some places. Handle on the dip stick is red; early coils are black, late ones are blue. I'm sure all of this is fairly well documented - no need to invent the wheel.

[Tomnistuff]

I really appreciate the quick responses and the crispy clear closeup photos.  I see in the photos pretty much what Benz Dr. describes in words.

I have decided that I will limit myself to the colors and coatings on the parts when they were installed at the factory and not worry about the inspection paint marks that got put on farther down the line.  Anyone who looks at the car, knowing that it's forty-seven years old, will know that it's restored and any brush-on paint marks are just faked anyway.

I noticed that The Lews' 250SL relays are black with white decals, the six-month old 280 somewhere here on the forum are apparently clear CAD or zinc plated w/o dichromate and your 65 230SL relays, Garry, are a combination of the two.  I assume that means that black relays = early models and clear CAD or zinc plated relays = later models.  Has anyone (who doesn't have a life) documented when these things changed?

I have decided to do my late 66 230SL like yours, Garry, with almost everything gold CAD except the hose clamps and the relays.  My hose clamps are all new zinc plated anyway.   Since I don't know how to get the white decal effect on black painted relays, I'll just clearcoat my bead-blasted relay covers with high-temp clearcoat, and buy some decals if WWheeler still has some (and if I can figure out which decals go on which relays).  My hood hinges are painted body color and I'll probably use CAD plated bolts on them.  If they look funny, I'll paint the bolt heads body color.

If anyone knows that I'm planning something incorrect, please let me know.

Thanks again for the responses.

Tom Kizer

[Cees Klumper]

As an 'aside' question, does anyone know how many years the cad plating usually lasts? So how long before it has to be done all over again?

[mdsalemi]

As an 'aside' question, does anyone know how many years the cad plating usually lasts? So how long before it has to be done all over again?

Cees, that's an impossible question to answer as it has everything to do with the environment which is different for each car and owner, and what kind of plating was done (quality, thickness, treatment, etc.)

However, keep in mind the following: true CAD (cadmium plating) lasts longer than zinc plating.  More often than not (guessing) people are having zinc plating done (which is silvery in color) and then the phosphate wash (which adds the gold color) as opposed to cadmium, merely because cadmium plating is harder to find.

That being said, the industrial measurement of how long these platings last is usually done with what is called a "salt spray test".  G-d forbid we would ever subject our cars to such a horrific environment. A typical standard would be found under ASTM B766, and an end result might be 480 hours of salt spray to red rust.  That's for Cadmium.

For zinc plating, the duration to red rust can be as little as 12 hours. The most common zinc specification is ASTM B633-07.

Pardon the pun--but take this with a "grain of salt".  There are so many factors influencing corrosion, and the quality of plating...it pays to study and research.  Thickness of plating, plating standard, phosphate washes, etc. all make a huge difference in how long things last.  Talk to a few platers, do a little research, find some materials finishing books, and arm yourself with some knowledge.

Concluding, let me quote one plater here: Cadmium use in harsh environments and aerospace application has no equal and Cadmium is second to none in aquatic or brackish application.  There are some that say you cannot find cadmium plating, and that's silly.  There are plenty of platers around, they just take a little more work to find. I've had cadmium plating done.  Cadmium plating will only go away when we stop making military aircraft.

My car: nearly all of the interior parts were done with barrel zinc plating with a gold phosphate wash.  The restorer chose to go local, and there were no local cadmium platers.  After 12 years now, a good deal of the brightness of the color has faded.  While there is no rust, and only minor signs of corrosion, the engine bay parts are ready for another round of plating.  When this happens--and I don't know when that will be--they'll be done in Cadmium, not zinc.

I have just finished doing all the cad plating in the engine bay on mine. Here are some photos

Garry--absolutely stunning!  I only wish I could see the car in person.