JM says "zinc or cadnium" which is it?

[Mike R.]

The 65 judging manual says the hood catches and pins are "cadnium or zinc plated" which is it?

[Peter J.]

Re: JM says "zinc or cadnium" which is it?

Either one, different suppliers used different plating methods.

[William C.]

Re: JM says "zinc or cadnium" which is it?

Cadmium was generally spec'd by GM for underhood applications in the 60's because it met the GM underhood corrosion specs without major problems. In the late 60's-early 70's the government got into the "heavy Metals" wars, Cadmium was a carcinogen and it was phased out over time. That is when the wire harness clamps began the "gold" appearance as bright zinc or tin (CRS Disease) with a secondary bath of gold irridite was found to have similar corrosion-resistance properties to the cad parts.

[Peter L.]

Re: JM says "zinc or cadnium" which is it?

I hope the JM say "cadmium."

[Donald T.]

Re: JM says "zinc or cadnium" which is it?

I've said it many times in the past. I believe GM rarely if ever used cad on C2 era vettes. GM specs specified zinc or cad, so naturally the suppliers selected zinc given the choice. I have replated many C2 parts and have never run across cad. I can't say cad was never used, but it certainly wasn't the norm. Part of the problem is that it is virtually impossible to distinguish cad from zinc with visual inspection, so what gets called cad is probably zinc.

[Ronald L.]

Re: JM says "zinc or cadnium" which is it?

I used to do the validation testing for all this stuff and don't agree that in the 60's Cd was nearly gone. By the mid to late 70's there was still plenty of Cd out there and some parts were spec'd "Cd Only" with suppliers trying to pass off Zn.

Don't even go there on how much of this stuff we handled...

While I have clear and obvious respect that Cd is toxic and is a severe theavy metal oxin, we handled those bolts and did those tests every day. The only worry GM ever had (back then) with heavy metal exposure was Chrome. If you were exposed to that you had to have an obligatory bend over inspection with the head site MD every year for 5 years minimum after your last 'potential' exposure.

Back on the Cd verus Zn debate - there was/is a simple test to flush them out. All you need is a known unmolested original , especially an area that has been protected and the chem-judge can decide. Issue is you lose the coating in this test and would have to have them replated.

Maybe this summer I'll test a pair of bubba modified hood pins that came out of my 66 hood, I think they are still around here somewhere.

[William C.]

Re: JM says "zinc or cadnium" which is it?

Depends on what part and what era. I can only speak to wiring parts, primarily from the late 60's on. We converted many cad parts to brite tin in the early 70's. Battery bolts were the most prominent, but there were smaller items also, like clips and clamps. that were converted. Essentially, I'm with Ron thru the late 60's into early 70's.

[Donald T.]

Re: JM says "zinc or cadnium" which is it?

Depends on what part and what era. I can only speak to wiring parts, primarily from the late 60's on. We converted many cad parts to brite tin in the early 70's. Battery bolts were the most prominent, but there were smaller items also, like clips and clamps. that were converted. Essentially, I'm with Ron thru the late 60's into early 70's.

I can't speak to wiring parts since I have never replated anything like that. The original question was regarding hood pins and catches, and I have replated many of these and all of them had zinc plating.