Cadmium plating vs. Zinc

[Aaron D.]

I'm new to this and far from Tech savvy, so i hope I'm presenting this question appropriately. Is Zink plating an acceptable replacement to cadmium on a NCRS Top Flight car? Due to environmental concerns cadmium has gotten increasingly harder to come by, and the cost has quadrupled. And if zinc is not option can anyone tell me what is. Thank you for any assistance I'm provided in this matter.

[John D.]

Re: Cadmium plating vs. Zink

Aaron, Cadmium plating is still readily available in some states.
I just re-restored a '63 Fi unit that had ugly blue zinc on it. Had all the parts cadmium plated and the difference was night and day.
Yes it costs more but it's still small potatoes in the cost of a restoration. Your judging sheet with Zinc may same something like plating not typical.
Try Beringer's Plating I have been using them for an eon now. 330-633-8094 1211 DeValera Ave, Akron, OH 44310
The trick to keep the cost down for the entire restoration is to give the plater large loads/batches. As much as possible. If you just send them a small amount it's very expensive. Take pics of everything you send or make a list. Beringer's does not lose parts. They plating is very high quality. Mention my name.
John

Beringers has a web site but I don't have the link.

[Joe L.]

Re: Cadmium plating vs. Zink

I'm new to this and far from Tech savvy, so i hope I'm presenting this question appropriately. Is Zink plating an acceptable replacement to cadmium on a NCRS Top Flight car? Due to environmental concerns cadmium has gotten increasingly harder to come by, and the cost has quadrupled. And if zinc is not option can anyone tell me what is. Thank you for any assistance I'm provided in this matter.

Aaron------


Much of the original plating on Corvette plated components which folks think is cadmium and describe as cadmium is actually zinc.

[Michael G.]

Re: Cadmium plating vs. Zink

Aaron, very very few people can tell the difference between the appearance of cadmium and zinc. So, if your goal is short term, i.e., to make it through judging without issue, then zinc will work.

With that said, however, zinc offers much poorer corrosion protection and performs completely differently from a tightening perspective, so they are not remotely interchangeable. I wouldn't switch a critical faster from one to the other...

[Michael G.]

Re: Cadmium plating vs. Zink

I agree with Joe, though, not much on most Corvettes was really cadmium.

[Aaron D.]

Re: Cadmium plating vs. Zink

Thank you Joe, Michael, John, & everyone else. You've been very helpful. The man at the zinc plating shop told me it takes a trained eye to know a difference. But we all know how that goes when your trying to sell somebody on something. To hear it here gives me the confidence to proceed. Atleast with the non critical parts where corrosion is not a concern. You have no idea how much i appreciate your answers, I was hesitant to ask the question due to never having posted to a forum before, being a new NCRS member, & being far from proficient on the internet. You guys have given me an indispensable tool in restoring these cars. I hope i get the opportunity to return the favor some day.

[Tracy C.]

Re: Cadmium plating vs. Zink

Aaron,

I've found that if the parts have a smooth finish, the zinc will finish too bright. If you lightly glass bead the part before zinc plating it you will end up with a very close approximation of a cadmium finish.

tc

[Irby G.]

Re: Cadmium plating vs. Zink

What parts on a '63 would have most likely been cadmium plated?
I'm just about to purchase my plating 'stuff'. Gonna get the power supply from Amazon and other materials, copy cad 3 gal from Caswell (just the powder and solution...don't need a bucket, buffing wheel etc.), and the zinc and cadmium anodes from rotometals.com.

[Michael G.]

Re: Cadmium plating vs. Zinc

Actually, cadmium can be very smooth, and just as glossy as zinc, as well as several different colors. It all depends on the processing and the chromate used by the plater. I've seen many, many different appearances of cadmium when new and I was on the GM plating committee for many years. I disagree that a trained eye can tell the difference. Maybe sometimes, maybe with todays limited, specialized, cadmium processing, but back in the day, very often, even an expert could be wrong.

Without looking at the GM prints, its difficult to say for sure what parts actually had cadmium in production. There will be a note on the drawing specifying what plating must be used. On most 63 fasteners (probably all, but never say never), the two platings were not optional in that note, only one was listed on the print. And the most common standard parts were zinc (or zinc phosphate and oil).

[Gene M.]

Re: Cadmium plating vs. Zinc

Actually, cadmium can be very smooth, and just as glossy as zinc, as well as several different colors. It all depends on the processing and the chromate used by the plater. I've seen many, many different appearances of cadmium when new and I was on the GM plating committee for many years. I disagree that a trained eye can tell the difference. Maybe sometimes, maybe with todays limited, specialized, cadmium processing, but back in the day, very often, even an expert could be wrong.

Without looking at the GM prints, its difficult to say for sure what parts actually had cadmium in production. There will be a note on the drawing specifying what plating must be used. On most 63 fasteners (probably all, but never say never), the two platings were not optional in that note, only one was listed on the print. And the most common standard parts were zinc (or zinc phosphate and oil).

One thing I will add to this is if you want your zinc plated parts to look correct as in bolts ask that they DO NOT chromate them after plating. Chromate was used on very few applications on 50's and 60's cars. It was an extra cost option GM did not spring for. There are some that did get a chromate such as dual master cylinder cover. Chromate does add more protection and gloss factor. It is available in clear, yellow and black. There may be others now. Zinc is an electroplating. Chromate treatment and Phosphate are not, just dipped in solution.

[Michael G.]

Re: Cadmium plating vs. Zinc

The chromate was added as a sealer, in order to seal the electroplated zinc (or cadmium) against plating (white) corrosion, as well as to close any plating fissures that would have exposed the base metal (steel) to water and other corrosive elements. While I agree with Gene that chromate will change the appearance somewhat (not too much, if you use clear), its sealing function delays corrosion quite bit, so unless you are building a trailer queen, the slight appearance difference is worth it in improved plating life. I used clear chromate on all the zinc fasteners on my Duntov 63, so the appearance didn't hurt during judging.

If you are plating, (with either cad or zinc) also remember that the thickness of the electroplate is all important in preventing corrosion so put on as thick a plating as will comfortably fit into the mating thread....

[Mark S.]

Re: Cadmium plating vs. Zinc

It may also be worthwhile to mention that in some cases cad plating might be a little more harsher on fine parts, like springs. Springs can sometimes loose their tension properties due cad process versus the zinc process.

[John H.]

Re: Cadmium plating vs. Zink

What parts on a '63 would have most likely been cadmium plated?

Irby -

None. Focus on zinc.

[Gerard F.]

Re: Cadmium plating vs. Zink

Irby,

If you use the cadmium anodes with the Caswell zinc solution, you will probably ruin it for zinc. I have an older Caswell zinc solution which I use with cadmium balls (from rotometals) and have dedicated that solution to cadmium.

I have a second solution which is the newer Caswell zinc solution and which works just great with the zinc ingots (from rotometals).

You really can't mix cadmium and zinc with the same solution. If you want bright zinc get that Caswell zinc brightener, it works just great for prefinished bright parts.
If you want the cadmium look with zinc, don't use the brightener and pre-finish the part to a duller finish.

[Robert B.]

Re: Cadmium plating vs. Zinc

I deal with a LOT of plated parts for the auto industry and the finish sheen that was plated on a monday when the plater changed the solution in the tanks versus on a friday after they had run a bunch of parts all week long looks a lot different. It is the same for CAD or NI. I am sure it was worse back in the sixties!