I bought a POR 15 kit to do the back side of the chrome bumper of my car. I've thoroughly read the directions, looked online, and can't seem to find the answer to an important question I have-will either the metal prep, or cleaner-degreaser cause any harm to the chrome bumper? Both products are brushed onto the rusted surface, then rinsed off. The bumper has mounting holes through it, and I'm concerned about the acid, especially in the metal prep, staining or etching the chrome. Of course their offices are now closed (Friday night) and won't open again until Monday. Anyone have experience with this product?

could you tape the holes from the outside, use some electrical tape and a couple layers.
Jay D.

How about putting a plug of a wine cork, the plastic kind in the holes. I've used the pro 15 on the inside of a convertible car floor, I wire brushed it, used the metal prep with a paint brush and then applied the por 15 when it was cleaned up. It's been going real well for quite a few years with no problems.
These chemicals are not that strong in my opinion that any harm will come to the chrome, just be sure and rinse real well and maybe even apply a car wax on to the chrome before you start to give it some kind of coating protection.

I tend to think outside of the box so try at your own risk on some of my suggestions.

TX
Mr fixit
Chris

Yeah, do NOT get that stuff on the front of your bumper. POR 15 is the strongest rust cleaner and sealer system you can find. Only use it on areas where you want to cure and seal off rust.