Cadmium Plating

[Harry]

I have been looking through various threads on plating parts in the engine compartment, but most were old and it was recommended to begin a new thread.  It sounds as though the original plating was cadmium (yellow/goldish)?  Are there still businesses out there that do cadmium plating?  (Any near East Tennessee?)

Also, what has been the success with painting instead of plating?  And for those who have do this, is there a specific brand and color that you would recommend?

Thanks as always,
Harry

[mdsalemi]

Harry,

Little has changed so the old threads are good. The big question purists have is "Was this part GOLD or SILVER?"
Cadmium plating by itself leaves a silvery finish. When a phosphate wash is added, it adds a measure of protection and a yellow color.
Plenty of information on the processes all over the internet. Just start searching.

In the production world, cadmium is largely relegated to marine and military uses because it is extremely toxic. Much of it has been replaced with the similar looking zinc plating, or tin-zinc plating, with or without the phosphate wash to give it that color and protection.

There are plenty of places that still do it...you just have to "let your fingers do the walking" or wait until someone with more recent experience than I chimes in...

[BaronYoungman]

I had a bad experience cad plating (actually gold zinc plating) with DeTray Plating Works Inc. in Kansas city just FYI.
Bob

[johnk]

Several members including myself have used plating perceptions in twinsburg Ohio for cad plating. I believe some found it worth shipping their product their. They are charging me 400 for the entire car including brake lines. 

The only thing is they have had the last pieces of my batch, primarilty the silver including break lines since early this summer. I haven’t been in a hurry though.

[Rick]

Gold Zinc plating is more common these days, but it simply is not as good as Yellow (gold) cad plating.  I have found there are those that mistakenly refer to gold zinc plating as "cad", but it is not.   Cad plating has a different sheen and lasts much longer than zinc.  Find a place to do real cad plating.

[Benz Dr.]

No one in Ontario does cadmium plating anymore due to its toxicity. I had a place near Detroit that did a couple of jobs for me and the consistency was perfect but I didn't like the color. It was fairly bright when first done and then it faded a bit so that it looked a bit more orange - bronze. In fairness, all of these coatings have a tendency to loose their shine as the coating starts to wear away.

The price of cadmium is several times that of zinc chromate and from what I've seen cadmium really didn't make the grade as far as appearance. Zinc chromate  looks the part but doesn't last as long so it's a bit of a toss up if you have both choices available, which I don't, so it's an easy choice for me. However, kept out of salt and other nasty conditions zinc will last long enough.

[mdsalemi]

No one in Ontario does cadmium plating anymore due to its toxicity.

Gotta look a little harder Dan...

H&E Plating in Toronto does true cadmium plating in their Scarborough facility. They also can deal with small batch stuff--meaning restoration...

https://heplating.com 

51 Comstock Road, Unit 3
Toronto, Ontario   M1l 2G6
(416)757-2897
Monday-Friday
7:30am- 3:30pm

Yes, cadmium is quite toxic, and thus for some applications (like production automobile uses) it has fallen by the wayside. For many if not most applications, zinc plating or some derivative will work just fine. However there are some very specific military and industrial uses where simply little else will do...thus it be getting harder to find but it isn't going away, even in Canada.

[MikeSimon]

As a supplier to the automotive industry, we had to drop cadmium plated mounting brackets on p/s pumps quite a while ago. The OEMs have a "requirement" list for their purchased parts they can show to the EPA. The only suppliers that are exempt are those you have to compete against - the sweatshops from China.

[Benz Dr.]

Gotta look a little harder Dan...

H&E Plating in Toronto does true cadmium plating in their Scarborough facility. They also can deal with small batch stuff--meaning restoration...

https://heplating.com 

51 Comstock Road, Unit 3
Toronto, Ontario   M1l 2G6
(416)757-2897
Monday-Friday
7:30am- 3:30pm

Yes, cadmium is quite toxic, and thus for some applications (like production automobile uses) it has fallen by the wayside. For many if not most applications, zinc plating or some derivative will work just fine. However there are some very specific military and industrial uses where simply little else will do...thus it be getting harder to find but it isn't going away, even in Canada.

I heard that someone was doing some aerospace work in the Province using cad but really didn't think they would do our kind of work. I'm going to stick with what I'm doing unless someone insists upon cad plating.

[mdsalemi]

If you go to their website, look at the tab "Small Batches" you'll see its kind of leaning towards our kind of stuff. There's a drawing of an old motorcycle and headlines of "restore". But, that's not all of what they do, they'll do zinc too.

[Tom in seattle]

Is it a fact that all the w113 cars  originally had certain cadmium plated parts?  I can find no indication that my parts have been other than zinc.  Also I have seen beautiful engine bays with cad plating done during restorations.    My car has no rusty parts except for some cooling hose clamps.  Did things change at some point or does cadmium change color over time?

[Rick]

Cad does decay in time.  Yes-- all the w113 cars, as well as most Mercedes, had gold cad plating on many parts.  Most the pictures you see of the nice engine compartments show many plated parts.   Look around carefully and I am sure you will find some remnant cad here and there.

[lurtch]

No one seems to have yet mentioned the DIY plating process available from Caswell (www.caswellplating.com).

I purchased the kit available from them and had good success with it. It was not quite so simple or easy to do this, but I was fascinated with the process and the results have been very permanent.  My injection lines continue to look very good. My write-up appeared in Issue 17 of Pagoda World (Aug 2015).

Larry in CA

[mbzse]

Is it a fact that all the w113 cars  originally had certain cadmium plated parts?.../...

Yes, certainly. Look at this factory original photo (1968)

[mdsalemi]

No one seems to have yet mentioned the DIY plating process available from Caswell (www.caswellplating.com).

Larry, Wallace Wheeler has mentioned in several different posts and threads over the years, his experiences with, for lack of a better term, "self-plating" using this and other kits. I believe he's done zinc and tin-zinc.

For those that don't click Larry's link to Caswell, just know that they offer a complete variety of home metal finishing kits--chrome, zinc, tin, gold, etc. One thing they don't offer, thank goodness, is cadmium. It's a little bit too toxic to have around your home..

[wwheeler]

No one seems to have yet mentioned the DIY plating process available from Caswell (www.caswellplating.com).

I purchased the kit available from them and had good success with it. It was not quite so simple or easy to do this, but I was fascinated with the process and the results have been very permanent.  My injection lines continue to look very good. My write-up appeared in Issue 17 of Pagoda World (Aug 2015).

Larry in CA

I have posted many times about the Caswell kit and have used it many times. It isn't for everybody and you have to be an experimenter. It isn't a plug and play. That being said it is great for doing small runs where you cannot get to a batch size at the platers. FYI, it is a Zinc plating kit, not CAD!

Another point that always gets confused is the type of plating. The two you would find on a Mercedes of the era are CAD (Cadmium) and Zinc. Both of these have been talked about many times here and no point going over that. But the color has absolutely nothing to do with the type of plating used. You can have both yellow CAD or yellow zinc. You can have clear CAD or clear Zinc (slight bluish tint). The color is simply a protective coat added after the plating is done. I would say that from a picture, it is impossible to tell if it is yellow CAD or yellow Zinc. It is known that Mercedes, as was the rest of the world, phasing out CAD plating in favor of Zinc for environmental reasons at this time. I don't think anybody has ever conclusively determined the year that they switched or what may be CAD and which may be Zinc.   

Given that, which to use is up to you in my opinion. Each has pros and cons.

[Harry]

Great information.  I would prefer the gold'ish finish on my items.  Is that finish a product of the kit that is mentioned?  Can that finish be obtained without the cadmium component?

Thanks,
Harry

[MikeSimon]

Yes, certainly. Look at this factory original photo (1968)

Careful with photos. Especially "old" ones. They are not true to color. Actually, back then, they weren't to begin with. In order to produce the correct colors in artificial lighting with photo film, you had to either use special lights or special film.

[wwheeler]

Great information.  I would prefer the gold'ish finish on my items.  Is that finish a product of the kit that is mentioned?  Can that finish be obtained without the cadmium component?

Thanks,
Harry

Harry,
Yes, Caswell offers the chromate solution that produces the yellow color on the zinc plate. It is a little tricky in the way you handle it. I can help you with that if you need it once you get the kit. Again, you have to be a bit of a chemist to get the best use of the kit. Caswell has absolutely no Cadmium products in its line.

[rumb]

I know this is an old thread, but thought I would add my .02. " The color is simply a protective coat added after the plating is done." This is sort of  true.  The yellow chromate process actually forms a microscopic honeycomb on the surface that is known as a sacrificial layer. Over time exposed to the elements this layer wears off and thus prevents actual rust from forming on the base steel part. Eventually all this layer goes away and the part returns to the silver/grey color which is the Cad or Zinc layer.  If that layer wears off then the bare metal will begin to rust. If you want a silver part, then just stop after plating and dont do the yellow chromate dip. By adding a "brightener" to the plating process you can make the part shine more.

[Benz Dr.]

The guy doing my plating told me that chromate actually has very fine particles of chrome in the solution and that's what makes it shine.

[wwheeler]

In theory, both the chromate and Zinc/Cad layers are sacrificial layers. The chromate protects the zinc/Cad layer. The plating is vulnerable to attack from acid among others and even from something like Coke-A-Cola. Then of course the Zinc/CAD layer protects the base metal from corrosion and rust. Yes, when the chromate wears off (and it does), the plating is revealed. Then when the plating wears off (and it does), the steel metal will rust. I am not sure how that is not correct.

Yes, you can add brightener to make the parts shiny but that is more of zinc look and not CAD. CAD is more of a dull finish. And yes you can leave off the chromate, but why leave off more protection? There is a "clear" chromate that only leaves a very slight bluish tint. That is what most hardware bolts are. To the untrained eye, they don't appear to have a chromate, but do. Using the Caswell Zinc kit, the difference is noticeable comparing clear chromate versus the plain zinc part.