rad cap plating question

[Steve B.]

I checked with my judging manual and it states that the radiator cap was cad or zinc plated in 1967. A plater that I spoke with does zinc plating but not cadmium, will zinc be OK for judging?

[Patrick H.]

Re: rad cap plating question

I checked with my judging manual and it states that the radiator cap was cad or zinc plated in 1967. A plater that I spoke with does zinc plating but not cadmium, will zinc be OK for judging?

Steve,

The manual is incorrect.
They were all plated in zinc, so you have nothing to worry about.

Patrick

[Jack H.]

Re: rad cap plating question

Actually, it's pretty hard to distinguish between zinc and cad...both are silver in hue! The JG books often use the terminology 'zinc/cad' as a compromise and frequently Chevy's purchased parts drawings gave the supplier a choice of the two.

Zinc is cheaper and these days MUCH more readily available from plating houses. I wouldn't be concerned about using zinc on your rad cap, but I would be concerned about how you're going to get the plater to do a correct job of 'selectively' plating the cap!

The center rivet was brass or aluminum (depends on which rad cap we're talking about) and the sealing spring on the bottom of the cap wasn't plated originally. So, most plating houses simply run the fully assembled rad cap through their plating tanks resulting in cap sub-assy components that now have the WRONG finish on them...

[Steve B.]

Re: rad cap plating question

Thanks for the replies!

[Peter L.]

Re: rad cap plating question

Steve - Is it zinc or cadmium plated? As Jack indicated, only your plater will know and you if he tells you. Pete

[Patrick H.]

Re: rad cap plating question

Actually, it's pretty hard to distinguish between zinc and cad...both are silver in hue! The JG books often use the terminology 'zinc/cad' as a compromise and frequently Chevy's purchased parts drawings gave the supplier a choice of the two.

Original specs specifially called for zinc, and this matches the results the testing we've done (see posts by Tony Hurtado). Granted, we did not test "every" radiator cap in existence but did test a variety of them.

I suspect that the JG gives the alternate only because the writer did not know the definitive answer.

Patrick

[Terry M.]

Re: rad cap plating question

I suspect that the JG gives the alternate only because the writer did not know the definitive answer.

Patrick

I second that suspicion.

[Patrick H.]

Re: rad cap plating question

I second that suspicion.

LOL!