gray phosphate?

[Barbara S.]

I found the correct one piece pulley/fan for my '67 s/b alternator. The JG reads that it should be "gray phosphate". I know what black phosphate is, but I'm not sure what the difference is between gray phosphate and black phosphate. Can someone explain it?

Thanks.
Tony

[Donald M.]

Re: gray phosphate?

Tony, gray phosphate is simply a dull or flat gray coating on the pulley/fan. The shade of gray varies from dark to light in color. The original coating does wear off with time and exposure and tends to resemble a light zinc or cadmium color.

[Joe L.]

Re: gray phosphate?

Tony------

Basically, the term is really "phosphate finished". However, in the vernacular the terms "black phosphate" and "gray phosphate" are used. The actual color of the phosphate finish varies considerably for a variety of reasons. These pulley/fan assemblies are usually towards the darker, but I've seen some towards the lighter, too.

[Gerard F.]

Re: gray phosphate? or black

Don,
I think the JG says "some" one piece pulleys were gray phosphate. My one piece pulley stamped 3909815AJ on an alternator dated June 16, 1967 looks like the original finish was black. Were all one piece pulley's gray phosphate, or were some black?

Shot 72, but only on the back 9

Jerry Fuccillo
#42179