1965 Disc brake splash shield finish

[Eugene B.]

Members,
I would like to refinish (have replated) the disc brake splash shields for my '65.

The JG states that splash shields are cadmium or zinc plated. It looks like there is a choice to be made.

What is the difference in appearance between the cadmium plated and the zinc plated finish? What finish was used by the factory? Lastly, does anyone have an electroplating shop that they can recommend to provide the most authentic look?

Thanks gents,
Gene

[Rob A.]

Re: 1965 Disc brake splash shield finish

Cadmium is a softer, duller looking finish than zinc. It actually does a better job protecting the metal. Cadmium lasts much longer. Old parts that have been cad plated may look dull and appear to have no plating left, but they will still be protected from rust, whereas zinc plating will wear away faster and allow rust to set in. The waste it produces is very toxic and in some states, like here in California, most plating companies aren't autorized to do cadmium plating. I found one place that has been doing it for years, and they explained to me that it is very difficult to get the approval and therefore, find it easier to do zinc plating. If you use a very fine steel wool, you can buff out zinc plated parts and give them the appearance of cadmium plating. If you find a good plating company that does both types, they can show you samples of each.

[Bryan L.]

Re: 1965 Disc brake splash shield finish

Try Steve Gregori in Sanger, CA. His website is www.detailplating.com I've used him on several different projects for the past 8 years and his work is flawless. Excellent turnaround time as well. He advertises in Driveline too.

BL

[Joe L.]

Re: 1965 Disc brake splash shield finish

Gene------

Actually, I think that these shields were originally zinc plated. Cadmium plating has always been significantly more expensive than zinc and I don't see why GM would ever have spec'd it on a part like this. It's possible, but I doubt it. If the spec called for cadmium OR zinc, then most, if not all, suppliers would have used zinc for cost reasons.

One more thing: I believe that some of these rear shields were made of pre-punch galvanized material. I know for CERTAIN that the original rear shields on my 69 were manufactured of this material. Pre-punch galvanized material means that the part was stamped out of a piece of sheet metal which was galvanized prior to the stamping operation. In this manner, when the stamping operation is completed, the part is finished---no further finishing operations are required.

You can identify such a finish by carefully inspecting the part. The silver finish of the part will be somewhat "mottled" and not completely smooth and even. The best and most accurate way to identify it, though, is to look carefully at the very edge of the shield. A part manufactured of pre-punch galvanized material will be bare steel on the edge since the dies cut the part out of the sheet of material. Since the material is so thin, the bare steel will be barely noticeable, especially when the part is new. After awhile in service, though, the edge will rust. It will also be barely noticeable since, as I say, the edge is so thin. But, if you look at it closely, perhaps aided by a magnifying glass, this characteristic will be readily apparent. The rust-discolored edge will include the entire circumference of the shield where it was stamped out of the sheet of material.

By the way, galvanization is done only with zinc. So, if a part is made of pre-punch galvanize material, then it is zinc finished. Consequently, zinc must have been an acceptable finish for this part, at least as of 1969.

[Eugene B.]

Re: 1965 Disc brake splash shield finish

Joe,
I have carefully inspected both splash shields. All surfaces and edges are lightly rusted to the same degree. I guess that since no original finish remains, this suggests that they were originally zinc. If they were cadmium, they would probably have less rust since cad. is a longer lasting finish.

When I removed the emergency brake anchors and looked a the surface that has been protected by the anchors, it appears smooth silver (no mottling). There is no rusting around the inner diameter of the hole.

I'm no expert, but analysis to this point suggests that the shields were originally zinc plated and appeared silver in color.

Regards,
Gene

[Eugene B.]

Re: 1965 Disc brake splash shield finish

Bryan,
Thanks for your response and information about Steve Gregori. I checked out his website and it looks like he's the guy for the job.

I was wondering about the cost. I believe that he lists the splash shields at $65. Do you know how many shields get plated for that amount?

Thanks again,
Gene

[Bryan L.]

Re: 1965 Disc brake splash shield finish

I sent him some 67 stuff in April. The shields were $65 a pair, the caliper mounts were around another $40 or so. He also did the p/b booster, m/c cover, and the hood latches. The booster was $125 (and beautiful), and the hood latches and all the various pieces were $80. Spent just over $300 for everything, and well worth it.

BL