Cadium??

[Jack A.]

Hi Guys,

In restoring my 61' I was reviewing some engine compartment paints and finishes in my NCRS Judging Manual. I found several references to a "Cadium" finish in some of the parts. I know I am going to need to use this on a few pieces. Do you know where to get it?

Thanks,
Jack Alexander

[Donald T.]

Re: Cadium??

Hi Guys,

In restoring my 61' I was reviewing some engine compartment paints and finishes in my NCRS Judging Manual. I found several references to a "Cadium" finish in some of the parts. I know I am going to need to use this on a few pieces. Do you know where to get it?

Thanks,
Jack Alexander

Jack,

Cadmium is a plating finish. Not familiar with '61 JG but it probably calls for either zinc or cad finish. GM specs typically called for either. Zinc is safer and easier, and the appearance is virtually identical to cad. You can purchase a home zinc plating kit from vendors like Caswell Plating, or you can send it out to a replater to complete the work. Search the archives for Caswell Plating and you will find more information than you ever wanted to know.

[Christopher R.]

Re: Cadium??

It's "cadmium." You won't find anybody who will do cadmium plating anymore. It's been pretty much replaced with other finishings. Cadmium may not be the worst environmentally hazardous material. But it's close.

Eastwood and others sell paints that mimic cadmium plating. Yeah, it looks like paint. But the color is very close.

[John D.]

Re: Cadium??

Chris, There are lots of shop in the USA that still do cadmium plating. Ohio is loaded with cad platers.

Try Beringer Plating in Akron, OH. Nice web site and very nice cadmium plating. Ask for Jim Beringer Jr.
Also a good cad plater in Twinsburg, OH. Precision Plating I believe but am not sure. Randy is the man to talk to there.
Lots of cad platers in New Jersey also.

[Jack H.]

Re: Cadium??

Agree! There are quite a few places that continue to execute cadnium plating despite the EPA's desire to shut them all down. Reason: there are 'niche' market applications (aerospace/military) where cad plating is MANDATORY.

So, those who specialize in catering to these 'niche' markets are CLOSELY inspected/controlled, but allowed to continue doing the work.

There's a shop just north of Denver (Aeropropeller) who does WONDERFUL cad plating work. You can almost eat off the floor at their facility AND they take on outside plating jobs (non-military/non-aerospace) with one of their 'welcome customer' groups being antique/classic car restorers.

One of the extra goodies you get by having plating work done at a place like this is, due to their frequent government inspections, their record keeping is SPOTLESS. Each job that comes in is documented and photographed (before/after pictures) meaning the typical plater's excuse (must have lost the part somewhere along the line) doesn't 'get it'... They have full in/out accountability to the individual part level to satisfy government inspection/record retention requirements!

[Gary B.]

Cadmium platers

All,

Richard Fortier, ex-owner of Paragon Reproductions, has a plater who will do cad. Richard appreciates what NCRS folks expect in terms of appearance and quality. Richard's contact info is in the Driveline.

Gary

[William C.]

Re: Cadium??

Just as an aside, in my nearly 40 years with GM/Delphi, I never saw a zinc/Cad option, to meet the GM underhood corrosion specs of the 60's Cad was a necessity, and was thus specified on the vendor print. In the mid-70's we started moving to Bright tin, which looks nothing like cad, then moved to gold dichromate wash after bright tin for enhanced corrosion protection, always trying to find something that would equal Cad. Each of these changes required hours of lab testing in salt fog environments and the requalification of each individual part Never did really find an equal, although the tin/gold dichromate used in the 70's was pretty good..

[Jack A.]

Re: Cadium??

Thanks Guys,

As always a very comprehensive response form all. I appreciate it.

Jack Alexander

[Christopher R.]

Re: Cadium??

John and Jack, thank you for the correction. I work in the aerospace industry, and we can't find them. Or, at least that's what my guys tell me. Perhaps it's MIL-spec cad they can't find. Or, a NADCAP certified guy. Thanks for cluing me in.

[William C.]

Re: Cadium??

One thing to remember if doing Cad for bolts is to bake the parts after plating, I don't remember the exact specs now, but cad plating induces "Hydrogen Embrittlement" in to the parts and the baking process relieves the hydrogen

[John D.]

Re: Cadium??

Bill, Beringer Plating in Akron, OH bakes the bolts and hardware but you pay extra. Typical charge for baking is 25/35 bucks. Failure to have the lock washers baked results in them breaking quite easily.
I used to know the temperature and length of time but forgot and so I don't rely on my guess of 375* for 20/25 minutes. By the way I was told they had to bake the parts within a very short time after they were plated. But I don't get involved with the plating process. I only expect a first class job and the rest is the platers job. JD

[Michael G.]

Re: Cadium??

At GM, cadmium and zinc were never considered to be completely interchangeable options on any part where either corrosion protection, or finish lubricity were issues.

Zinc plating is very much worse than cadmium in its resistance to corrosion, even with the addition of advanced surface sealants which became available in the 1980's.

Zinc is also extremely high in friction, cadmium is very slippery, a difference which means that their tightening specifications on similar fasteners are VERY different. Substituting a zinc plated fastener for a cadmium one in the same attachment without significant adjustment in the tightening specification may result a joint that is well below its intended performance envelope.

Regarding hydrogen embrittlement: Both zinc and cadmium electroplating processes need a baking step to "relieve" the hydrogen introduced to the steel during the plating process. Electroplating high-harness bolts without some degree of expertise in this area is risky business.

Finally, as I've stated here before, cadmium is a bio-accumulative carcinogen; its nothing to mess with.

Mike

[John N.]

Re: Cadium??

Hi Guys,

In restoring my 61' I was reviewing some engine compartment paints and finishes in my NCRS Judging Manual. I found several references to a "Cadium" finish in some of the parts. I know I am going to need to use this on a few pieces. Do you know where to get it?

Thanks,
Jack Alexander

Jack
There is a article in the Restorer,Summer 1992 page 12 where I took a series of parts from my 61 Corvette to a lab to test for original plating. The results are listed. Yhere was a lot of zinc as well as cad used on my 61. Several parts also had the additional yellow finish.
Regards






Regards

[Jack A.]

Re: Cadium??

Hi Guys,

Thanks for all the great replys. John also that thanks for the heads up on the article. That was my follow up question on what and where was Cadmium plating used on my 61.

Sorry, it took awhile to extent my appreciation for the additioal reply's. I was away.

Jack Alexander 35730

[Troy P.]

Re: Cadium??

I zinc plate parts at home for my resto projects. In my opinion zinc and cad do not look the same. Zinc is very "white", a pure silver look, whereas cad has a "blue" tinge. I am experimenting on making the zinc look more like cad by using a blue chromate dip after buffing out the zinc plate.