[VAC] Re: Anodizing aluminum & script rehab

[Dr. Gerald N. Johnson, electrical engineer]

The scripts are probably a zinc alloy. Commonly used for automobile
ornaments for about a century. They all fail with pitting in the chrome
plate when not heavily copper and nickel plated because the chrome layer
is porous. Its hard to plate smoothly because electroplating tends to
emphasize any surface rises, plating more metal to them. So material has
to be perfectly smooth before plating and then polished smooth after
each layer. Which is why the copper and nickel inner layers are often
not applied.

Now that you've filled with bondo plating isn't possible unless you were
to use an electroless technique (as used to plate copper on insulating
PC boards) to get a layer of copper over the bondo. But the bondo
probably stand the plating bath chemistry.

Polished anodizing is hard to accomplish. It might be easiest to buy
anodized door protection plates factory made to size. Don't mix brass
and aluminum on the exterior of the airstream. Water will cause a
battery and pitting corrosion.

The bright brass finishes on modern plumbing fixtures is a vacuum
chamber deposition of other metal oxides. Can't be done in a garage or
basement workroom easily.

Gerald J.



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