Cadmium Dichromate Plating...

[Patrick T.]

The NCRS Judging Manual specifies that the face of the '67 small block fan clutch (second design) should be cadmium dichromate, while the rear portion of the clutch body is natural aluminum.

First of all, we are talking about a gold color, right? I have the correct fuel pump on the engine and the lower half is cadmium dichomate per the Judging Manual and it's gold in color.

Secondly, how can they plate just the front of the cover only and keep the back of the body natural? I don't see how it can be done. Am I missing something here? Thanks, PT

[Jack H.]

Re: Cadmium Dichromate Plating...

Yes, 'dichromate' means gold tone...this is a post plating dip in chromatic acid after cad/zinc plating to help seal pores and further enhance the protection of the plating.

The face of the clutch is one part, the clutch housing is another part. The face was stamped (Eaton, coil spring style clutch) and the aluminum housing was cast. The two were put together by Eaton during fan clutch assembly, so there was no 'selective' plating...

[Patrick T.]

Re: Cadmium Dichromate Plating...

Thanks Jack, that was just the information I needed! PT