We pulled the bumpers off the 67 Malibu we're re- doing. I'm not sure these are original. In fact, probably aren't. But there is no rust on the front side of the front bumper but there is some surface rust and dirt on the back side of it.

How do I kill it without hurting the chrome on front side and what do I coat it with? Should I use silver POR? Can I do that without treating the metal first? Is there a solvent that won't stain the Chrome but will prep the metal and neutralize the rust?

I had some surface rust on the back of mine. I just used a hand wire brush and an electric wheel and got rid of the loose stuff and the undercoating. Then I used wash and wipe (you can use marine clean) and then I used POR semi-gloss over it. Depending of the surface you don't have to etch that part with metal ready.

Thanks