plating, anodizing, & finishing Q&As since 1989
What can I do to prevent polished aluminum engine parts from tarnishing?
Around a year ago my friend purchased a "header" and a down pipe for his car to replace the stock ones. I think they were aluminum polished. When he installed them he was touching them with his bare hands, instead of using gloves. As soon as they were installed he took the car for a test run. When he returned the finger prints he left on the parts already started to turn a different discoloration (tarnish).
Currently his parts have tarnished to a black colour. It was pointless to upgrade to these parts because they now look like the original rusted parts.
Myself and my group of friends visit alot of car shows, we frequently see cars with polished aluminum or chrome engine parts that always look like a brand new mirror finish.
I don't understand how this is possible to keep the parts from tarnishing considering some of these cars are "daily drivers".
Is there a durability difference between polished aluminum and chrome ?
Is there anyway to prevent the engine parts from tarnishing ? I would really appreciate any insight.
- Toronto, Ontario, Canada
You will have to remove the pipes and either have them chemically or mechanically cleaned back to their original finish. Then they should be taken to a powder coater for finishing with a high temperature (resistant) clear powder coat.Gene Packman
process supplier - Great Neck, New York
A car has two headers.... the inlet and the exhaust header.
If you are talking about the exhaust header.... & you do mention rust ... holy cow, an aluminum one would FAIL pdq on any car and on a hotted up car (where on idling (no fan, of course) the headers would glow red hot after 5 minutes and should burn off any paint! ... I know, I've done it!
But if the vehicle is for S H O W and not G O, then follow Gene Packman's suggestion and use a high temperature paint [affil link].
Re finish of aluminum versus chrome, well, chrome stays nice and bright whereas the aluminum will oxidize slightly and lose its shine eventually.
And if you go to these car shows, ask the exhibitors just what THEY DO ... they'd be glad to tell you if you ask them nicely and say Wotta nice Car you 'ave!
Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
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