Does anyone know for sure what the material is/was that GM used for the "Pot-metal" items?

Was it Zamak? Perhaps Zamak 3? (made mostly of zinc material, with small amounts of aluminum, magnesium, Copper.)

Or- does anyone have more information or experience with Zamak? I do not & but have been reading about it on the web to try and learn, for this project.

I am refinishing the surround piece on taillights, for a '68. It could be helpful to know what this material is before I try to spray them. My intent is to use a 2k epoxy primer first.

 

So many trim pieces and bight work were pot metal in the ‘60’s, this could be a very interesting thread. Over the decades I’ve found you either get lucky with NOS or lightly aged trim, or you get the pitted parts that work but look terrible.

I’ve also found that it’s mechanically usually a little bit brittle. Especially after decades of use….

It would be great to know how to refinish these parts, if possible without heading for the ever decreasing number of plating shops.

Chris

 

Is it fair to guess you are using 2K epoxy primer, that you intend to paint the parts ? I would be more curious to see if the primer will stick to the parts.

I think you'll need to abrasive blast the pits to remove corrosion. A really fine grit and lower air pressure might be what you need to use. Spray a small section with the primer to see how it sticks.

 

I wonder how a chrome wrapping material would work?

 

It's called pot metal for a reason. It's mostly zinc, with trace amounts of different metals. I know different manufacturer's use slightly different formulas ( or pot luck?), perhaps different yer to year.
In any case, that shouldn't concern you, if you are just painting it. Epoxy is a great primer to use on it. Use it before trying to fill pits with glaze, if you like. If a part is perfect, even an etch primer will stick very well to it.
And, of course, any paint will stick to the epoxy.