CAD Plating

[mdsalemi]

Hello Gents,

A question often asked, but rarely answered has been regarding "CAD" plating.  By "CAD" plating I am referring to, collectively, cadmium plating; zinc plating; and tin-zinc plating.  These are protective plating finishes used on non-decorative steel parts.  Decorative parts typcially use chrome, of course.  For example, the "gold" color on many steel parts inside the engine bay, including the fuel injection lines, was probably originally a cadmium plate but today would most likely be a zinc plate with a yellow chromate finish, or zinc iridite.

When you ask anyone about this kind of plating--as I have been for some time now--you typically get no answers, or you get elusive answers such as "Oh, I USED to know someone that did that, but they don't do it anymore".  Or, "Gee, the EPA shut them down" or some such response that doesn't help.  Nobody has been able to give me the name of someone who does this kind of stuff, and I've been asking; I think people are keeping it to themselves.  Even my restorer wouldn't part with a name, because the guy he used was a production house and did it as a favor; the last thing he wanted was a bunch of auto restorers all with different parts to plate! The problem with these answers, true as they may be, is they lead you to believe it can't be done.  STUFF AND NONSENSE I say!!  Every single nut and bolt you can buy today is zinc plated.  So are thousands if not millions of all kinds of parts.  Nuts and bolts are also available with different color finishes as well.  So, with this in mind I went searching.  I badgered some people as well, and I did come up with some real and useful answers: I found two sources:

http://www.burbankplating.com/  Contact: Andy Scheer

These guys will help restorers, but you won't glean that from their website which looks like they are a production house only.  I contacted them and they said no problem; but there is a $100 minimu charge.  If their website is accurate, CAD plating is alive and well, thank you very much, and with ISO quality as well!  So there.

Another source I discovered from a local restorer here:

http://www.detailplating.com/  Contact: Steve Gregori

I have several items on my car that were not restored "correctly" as Jonny B and the other judges at Starfest let me know.  For example, my latch mechanism on the trunk/boot should be a silver look zinc plate; however it was painted silver instead.  Not correct.  Then, my automatic transmission filler tube was correctly plated and restored, alas some mechanic forgot to double wrench it upon reinstallation and the end looks like a twisted cruller.  I purchased a new pipe, but Mercedes decided to paint it instead of plate it.  So off to the platers it must go.

Now, if I go searching, I'll probably find a few more pieces that need to be "corrected" as it were.

If anybody has a small quantity of parts or a single part that they'd like plated, contact me off line.  I am preparing a few things which should be sent out in January.  The more we have the better the pricing will be.  If not, bookmark these websites for your future reference.  this would only be for things you can part with for some period of time, like a good winter project.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[TA250SL]

My resource for zinc chromate plating is APC in Burbank at 323-245-4951.  Last year their minimum charge was $40.  Parts should be free of paint before sending.

Tom

[Joe]

I'm interested in having all of the engine parts that are supposed to be cad plated replated. If someone could provide a list of these, it would be wonderful. (Sort of hard to guess by looking at a deteriorated engine compartment.)
Also, is it helpful (economical) to clean up the parts with a wire wheel and parts cleaner before sending them off?
Thanks,
Joe2
1965 230SL, Manual Euro
1971 280SL, Auto

[mdsalemi]

Gents,

In preparation for upcoming Concours, and based upon last year's Starfest, I'm tidying up some details on the car.  Two of these items are the auto trans filler pipe, and the trunk latch that sits on the deck (not the part on the body).

Regarding the filler pipe, sadly during one of my transmission woes of 2002, some well meaning mechanic failed to "double wrench" the pipe where it fits on the transmission, resulting in the pipe being cracked (but no leak) and twisted like a pretzel.  Not a problem getting a new one from MB, but in the tradition of so many other of their new parts it was painted black rather then CAD plated.

Regarding the trunk latch, it was spray-painted silver by the restorer and fooled nobody--certainly not Ted Gottfried and Joe Alexander!

So I just sent these pieces out for proper and true CAD plating and got them back today.  W O W.  There really is a distinct and noticable difference between true Cadmium plating and the zinc plating that is most often done today.  Pictures don't do it justice but those who are coming to Columbus in July can see the difference themselves.  My old filler pipe was zinc plated with a gold wash; the new one was true cadmium plated with a gold phosphate wash.  The trunk latch is clear wash leaving the bright silver of plain Cadmium plating.

Prime Plating of Sun Valley, California was the vendor.

One thing I discovered during some of this research is that there really isn't much of a price difference between true Cadmium plating and the ersatz zinc plating.  Cadmium plating has no substitute in certain aerospace applications, and is alive and well, albeit largely replaced in the automotive field.  Therefore, if you are going to the bother of "detailing" your engine bay, and getting the fuel lines and linkage pieces, etc. replated, you should go with real cadmium plating.  Leave zinc plating to the people who make nuts and bolts.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[Vince Canepa]

Actually, zinc isn't good on threaded items - it is pretty thick and it loads the threads.  There is a difference between cad and zinc, but my experience has been that cad doesn't last very long.  Some will argue the opposite, but this has been my experince.  Also, if you want cad to look right, the surface must be properly prepared.  I had some items ddone with cad II (the gold wash) and the plater did a lousy prep job.  All my items came back looking olive drab and had to be redone.  What a pain.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[mdsalemi]

quote:Originally posted by Vince Canepa

Actually, zinc isn't good on threaded items - it is pretty thick and it loads the threads.  There is a difference between cad and zinc, but my experience has been that cad doesn't last very long.  Some will argue the opposite, but this has been my experince.  Also, if you want cad to look right, the surface must be properly prepared.  I had some items ddone with cad II (the gold wash) and the plater did a lousy prep job.  All my items came back looking olive drab and had to be redone.  What a pain.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

Hi Vince--well it goes without saying (so why am I saying it??) that for ANY kind of plating, preparation is essential.  I was going to send my stuff to Burbank but he was unsure of how the filler tube would fare in their tumbler, and recommended Prime because they are better equipped for "hand work".

The measure of steel platings is done in "salt spray" tests, and the industry generally acknowledges that Cadmium plating is a higher quality, longer lasting then zinc, your experience not withstanding.  The lubricity of cadmium is one reason why it is preferred for some things in the aircraft industry, and while zinc may load up on threads, perhaps 99.99% of all steel nuts and bolts are barrel plated with zinc.

If your plater sent you back parts that were supposed to be gold wash over cad, perhaps they did it wrong; i.e. you didn't get a bad gold job, you got the wrong olive drab wash!  My research indicates that there are generally 4 colors listed for the final finishing of cadmium plating: clear (silver) yellow (gold) olive drab (what you got??) and black.

Burbank Plating has this to say about Cadmium, and one of the new alternatives, tin-zinc:

Since we have been in the cadmium plating business for 35 years we are very familiar with the need for more corrosion resistance than zinc plating can provide. Cadmium provides 2-3 times the protection of zinc. It is always been the finish of choice when the part is going to be used in an aerospace or marine application, or any other critical or corrosive environment. Lately there has been some aversion to cadmium because it is a toxic heavy metal. We offer one of the best alternatives to cadmium. Tin Zinc is highly resistant to corrosion because of the dual protection of the two metals. Tin Zinc has become the finish of choice when extremely high levels of corrosion resistance are required. We have tested our Tin Zinc and it resist white rust for over 200 hours and resists red rust for over 1000 hours. We are approved by the big three auto makers for our Tin-zinc process.


Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[TheEngineer]

This local restorer, John Kane, uses a 5 gallon container, a strip of metal and a flashlight battery and does his own cadmium plating. The solution he buys from Cascade Chemical. I have done a similar thing electropolishing stainless steel. The battery must be replaced when it goes low. I did use a battery charger. I saw several small parts he Cadmium plated: The largest was a hood latch mechanism for a Ferrari. It looked good. Industrial Plating here in Seattle also does Cad plating but charges a substancial minimum fee.

[Vince Canepa]

Michael - Perhaps I wasn't clear in my statement.  To have steel parts Cad plated and to come out looking "factory new", the plater must have the surface prepared back to "new" steel condition.  The plater that did my work simply acid cleaned the parts.  When they went into the plating process, they were more "grey" that "steel" colored.  Therefore, they came out very “green” and dull.  I have also run into this problem when plating other pieces.  Zinc seems more forgiving.  Think about the hand work that would be necessary to do injection pipes, etc. and bring the surface up to a condition where Cad will look right.  It might be worth it, if you can afford it.  As for marine applications for Cad, I've spent almost forty years in the commercial maritime industry and have never seen it used.  Maybe the military specs it out.  The ultimate test of durability is how the plating performs in service.  On most M-B of the era, in normal service, the plating was shot in a few years.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[mdsalemi]

quote:Originally posted by theengineer

This local restorer, John Kane, uses a 5 gallon container, a strip of metal and a flashlight battery and does his own cadmium plating. The solution he buys from Cascade Chemical. I have done a similar thing electropolishing stainless steel. The battery must be replaced when it goes low. I did use a battery charger. I saw several small parts he Cadmium plated: The largest was a hood latch mechanism for a Ferrari. It looked good. Industrial Plating here in Seattle also does Cad plating but charges a substancial minimum fee.

OH-MY-GOD.  Well--this sounds like irresponsibility to me.  Shame on John Kane, and shame on Cascade Chemical!  There are two reasons why cadmium plating has fallen out of favor and why it is dangerous.  First is that cadmium is a toxic heavy metal.  As such it requires special handling and disposal.  Does not sound like Kane's bucket fits the bill on this one.  Second, is that the cadmium plating process uses a cyanide solution.  While not a metal, an extremely lethal chemical.  This stuff does not belong in a bucket in the back of some guys shop!  What, is he trying to save a few bucks?  Steer clear of his shop, that's for sure...this kind of plating with toxic chemicals and metals is best left in the hands of professionals who do this for a living, not in the hands of some thrifty restorer with a bucket and a battery trying to avoid a minimum charge.  My goodness.  Cadmium and Cyanide can get in your body in any number of ways so I'd never go near that place...what he might save in minimum plating fees he'd surely spend on minimum cyanide disposal fees and the license to do it!

P L E A S E let's not try anything irresponsible people--I hope for your sake, the sake of your family and our environment that you leave metal plating to the professionals--and check their references as well.  Not only their QUALITY references, but their certifications with their respective states.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[Tom]

I bought a plating kit from Caswell Plating and have been very satisfied.  The term "cad" plating generally refers to the yellowish color of the injection lines, bolts, etc.  Using the Caswell system, a part is first bead blasted, then zinc plated by dipping in an acid bath with electrodes and a anode of zinc.  After rinsing, the zinc plated part is dipped in a bath of yellow dichromate.  This "etches" the zinc to create the yellow look.

It is not "cad" plating with cadmium, (probably highly regulated and not available to the hobbyist) but the look and durability is good.

1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Deep Red (Project Car)