Sorry if this topic has been covered.
I have a Mugen 4-2-1 header that I bought used. I spent about 2 weeks polishing it and by the time I was done it looked new. After about 2 weeks of driving it started to look oxidized. Just wondering if any one knows any way to prevent oxidization on these headers. I used fine grit sand paper to polish it, starting from 1000-2000 grit. I'm not sure if that could have contributed somehow but any input would be great. I'll try to get some pics up.

 

Send it off to jet hot and let them coat it inside and out.
it will still look the same after a year or too

 

What John said.

Also make sure you never get fingerprints on a non coated header. The body oils burn off when it gets hot and that residue corrodes and turns to rust. Simple to fix but it is time consuming and annoying.

 

is that ceramic coating?

 

Only way to prevent oxidation is to have it ceramic coated.
You didn't do anything wrong, they just start to change colors because of the amount of heat going thru the headers.
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Carlos Tirado
TiradoCustomCoatings