Painting the trunks/engine bay/underside/cabin, POR-15 and leave black? Options

[boxsterfan]

I have been thinking about what I will do with my car in the future when it comes time to restore. On many cars, I see people have appeared to POR-15 (or other) the trunks/engine bay/underside/cabin and then left it black? They then go on to paint the rest of the car as normal (orange, red, white, green, etc...)

I'm not looking to build a concourse winner myself. I am looking to build a car that is restored and protected from rust for as long as possible (another 40 years lets say).

What do people think of POR-15'ing (or any other product) the trunks/engine bay/underside/cabin and then leaving those areas as that? And then (in my case blue) painting the rest of the car as normal?

[rick 918-S]

P- paint O- over R- rust I thingk the product needs to have a chemical reaction with rust to bond properly.

I'm not sure but I think unless the metal has been sand blasted the product will have adhesion issues on clean bare steel.

[914_teener]

P- paint O- over R- rust I thingk the product needs to have a chemical reaction with rust to bond properly.

I'm not sure but I think unless the metal has been sand blasted the product will have adhesion issues on clean bare steel.

Rick is right.

It is meant in most cases to be painted over. Call them if you have questions. They are very informative.

Rust is an oxide. What their piant does is covert the oxide into a protective layer that helps prevent further oxidation.

The idea behind the phosphoric acid is to etch "new" or bare carbon steel so that the surface has "teeth" and then you apply the product. If this isn't used on "raw" metal or un-oxidized carbon steel....it will peel.

The same thing will happen to powder paint on bare carbon steel if it is not de-greased and then washed with a solution of phosphoric acid to the metal prior to powder coating.