Evidence of seat belt brackets being Cad plated??????? 1963

[Peter L.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

Joe - As a chemist, I find these discussion regarding Cd & Zn plating to be very interesting, because I don't know how one can distinguish visually between which element, Cd or Zn was used. To draw a conclusion as to which element the seat belt brackets were plated I would suggest reference to original drawings that specify the plating or some chemical analysis of the plating would be the best "proof." Pete

[Gary B.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

Pete,

I've read many testimonials on the DB about how it's difficult or sometimes near impossible to distinguish visually between cad and zinc. That issue isn't what interested me about JR initial posting. The issue I was interested in is whether the seat belt plates were natural vs. S-G black paint vs. plated (cad/zinc). I think the consensus, albeit a small one, is that they were plated. Whether that's cad or zinc is of no interest to me as I've had mine plated in zinc and I'm not about to change them to cad.

Gary

PS: Maybe JR is interested in the question of cad vs zinc, but I'm not.

[Richard M.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

Joe, Great info-thread. I just went through this on a '67.

I removed those 4 seat belt brackets and saw no remnants of plating on the backsides. Years of Michigan roads in it's early years likely removed evidence. The outsides were surface rusted, but as I removed one of the inners, the welds holding the stud on were loose and the stud fell off. There it was............obvious plating in several places. Sorry no detail photo, but also plating on the threads of the stud for the frame cable.

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Evidence confirmed. I repaired the stud, media cleaned all 4 and had them zinc plated.

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BTW, even if originally cad plated, to find a CAD plater these days is difficult and pricing is very high. I have one that does both CAD and Zinc in Orlando, Penninsula Plating, a 1.5 hr trip, and reserve CAD for only some engine related FI items. I use zinc for other items. That shop does work mostly for the aerospace industry and much CAD on aircraft and rocket ships. Pricey process due to the hazardous materials.

Rich

[William C.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

Yes, CAD is pretty hazardous stuff. as I recall, Packard Electric Changed all it's Cad plated parts to Zinc in the 1970's to keep ahead of OSHA in the manufacturing plants.

[Gary B.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

Rich,

I'm just guessing, but I think the quality of the original GM plating on these plates must not have been very good, since so little of it is often found, typically only on the backside or in nooks and crannies that were protected in some way from the elements. Combined with the fact that service replacements and repros are unplated probably made most restorers concluded that the originals were also unplated. I know I went down that exact path before I dug into things and eventually convinced myself that they were plated.

Gary

[William C.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

We switched our parts from Cad To Bright Tin, looked better, and passed durability testing.

[Gene M.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

I think you will find that the under car seat belt braces were zinc plated originally. They were of a lesser quality plating since they as most pieces GM plated, were not chromate treated. A chromate treatment will give a much better look and shine to the finish. It is a secondary operation that GM did not want to incur the cost of. I do not see any evidence that the originals were stamped from preplated metal as the die marks would scrape off the plating. The pins were welded and it is a general practice to plate after welding for obvious reasons another reason to not use preplate.

Most companies as Bill indicated were not using cadmium as a rust preventative inleu of zinc even in the '60's.

[Gary B.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

We switched our parts from Cad To Bright Tin, looked better, and passed durability testing.

Bill,

Just curious. Why bright tin and not zinc? Does bright tin look like cad or zinc? But have more durability than zinc?

Gary

[John H.]

Re: Evidence of seat belt brackets being Cad plated??????? 1963

Most GM (Chevrolet) drawings back in the 60's for plated parts gave the manufacturer the option of either zinc or cad plating; with cad being much more expensive, few suppliers opted for cad when they were trying to get every penny out of their cost, and zinc became quite popular. When cadmium was proven to be a skin-touch carcinogen in the early 70's, it disappeared quickly from volume automotive use and today is found only for specialized applications like aircraft propeller shops.