<VV> Why would anyone... WAS Bad paint product warning

Tony Underwood tony.underwood at cox.net
Tue Jul 16 00:05:01 EDT 2013

At 11:40 PM 7/15/2013, Tony Underwood wrote:

>Ladies and gentlemen:  It's ANODIZING, not paint.


The steel parts of many automotive components are gold hue but it's 
not anodizing. Steel can't be anodized like aluminum.  The golden 
tone on steel parts is "yellow-zinc" plating.

Anodizing is an interesting way to protect aluminum by dipping it in 
a sulfuric acid solution with an electrical potential applied as if 
plating the metal, only with the polarity reversed, with no "cathode" 
to plate with or dissolved plating solution (like copper sulfate or 
chromic acid etc).

After the aluminum is anodized, it must be sealed to make it 
water/weatherproof.  Before sealing (usually by boiling in a water 
based sealing solution, or even plain water) anodized parts are 
porous and can be dyed almost any color with a variety of 
dyes.  Anodizing coloration can be anything from black to white and 
everything in between, including plain clear anodizing like the 
aluminum brightwork/trim on most older cars.

An anodized coating can be very hard and durable if done right.  It 
can also, depending on the finish/polish of the original work, be as 
bright as chrome or as matte as a sandblasted anvil.

Just fyi... so sayeth my electroplater's handbook.


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