I have a lot of black underhood parts that have a grey oxidation on them. Some are large or unavailable to paint (AC Compressor and brackets,etc) that I can't just throw in a blast cabinet. Rust is not a problem here...just the "greyness".

Any special tricks or products to restore the black as non-invasively as possible?

TIA

C.J.

 

That oxidation should be able to be removed without harm with a little paste wax.

 

Just spray some No Touch Tire spray on the parts and let it sit for a few minutes then wipe it down.

 

Or you can used compressed air to blow it off the parts, to make it even easier.

 

It's paint like the outside of the car so treat it the same way for oxidation.
I'd use Meguirs #2 fine cut cleaner and if it looks too rough when that's done follow it up with #9 swirl remover, they can both be used by hand.
It's like rubbing out paint so it's going to increase the gloss whatever it is.