Oldsmobile Center Caps

[starfire]

OK, I've built up a collection of 15 caps in good shape (4 appear to be NOS) and three in terrible shape. I've got two questions about these if anyone wants to show off how smart they are:



1. The outside appears to be aluminum, based on the way they react with a magnet. The magnet is barely attracted, but I think that is because of the steel "fingers" inside that hold the cap to the wheel. So, does anyone know for sure that they are aluminum?

2. If they are aluminum, do they have a coating on them (like aluminum wheels sometimes do)?

3. Most of my caps look like the aluminum is brushed. But a couple of them look like they are polished (almost look like chrome). Did they use a different finish on these in different years?

4. Most of the decals on my caps are black, with a hexagon around a rocket on a red background. But four of them are black with a hexagon around a rocket on a black background. Anyone know why some rocket backgrounds are black and some red?

No prizes for correct answers other than bragging rights that you know more than me (which is not really saying a lot...)

Thanks,

[lleelduo]

I have not seen the Olds caps new. IF they are aluminum then the finish is probably brite anodized. Where that has gone bad is the white cloudy appearance. I would say they were a Polished appearance to match the polished stainless insets that go in the wheel slots on the Olds and Buick rally wheels

[zeke]

Could be cast in white metal.

http://en.wikipedia.org/wiki/White_metal

[cammerjeff]

Alan,

All I can add to this is the 79 Firenza I parted out had chromed pot metal caps in very bad shape, so I would guess the Aluminum ones would be earlier model years.

[starfire]

Is pot metal magnetic?

[Monza Harry]

No Pot Metal is the same (perhaps very slight variations in alloying amounts) as white metal, Aluminum and Zinc, and that would have no magnetic effect, perhaps as suggested you are feeling the inner snap clip. That second alloying element o is the reason for the low weld-ability, zinc is what we use for galvanizing. I am absolutely positive these parts from that era are all "die-cast white metal" Harry

[starfire]

Hmmm, I did some reading up on pot metal, and I think that is what they are (they do seem too heavy to be aluminum). Looks like with some metal polish and some elbow grease I should be able to get them shiny again. Mask off the decal and spray them with clear coat and hopefully they will stay shiny for a while. I'll see how shiny I can get them and post some before and after pictures.