What is "correct" for undercar undercoating?

redrag64 said

Be careful with the "rust converter." You said that you will have it "completely rust free...." Many rust converter products are specifically for use on surfaces WITH rust. If there is no rust present, they can actually create rust. Not sure about the Rustoleum product, but I would double check just to be safe.

Click to expand...

Well, OK...maybe I exaggerate a bit. As "rust-free" as a whirling porcupine (wire wheel) on the end of an electric drill will allow, which as you can surmise, still leaves some pitted metal and iron oxide deposits behind!
I am considering painting over the converter with regular Rust-Oleum paint, and then undercoating. This car will never see salt or winter driving again as long as I own it, so maybe this is overkill....but this is a job I never want to do again. So it needs to be right!