The Prep-Step primer sounds like a phosphoric acid base...of course all the market-babble makes it hard to tell...one would think the process is rocket science.

Anyway, it appears that Rust-Step is merely a very good paint, but any rust painted over would still be, well, rust. But if it works, so much the better.

Yeah, I would have preferred to do a phosphoric acid thing, too. I agree with you totally on some sort of acid pickling or passivating before paint. But expediency ruled today. My rusted Kwikee has been offending me, and my wife got involved. I guess their claim is that their paint is so good that rust doesn't have a chance. Sounds a little like POR15. However, that being the case, why do they sell the Prep Step, which is probably phosphoric acid?

We used to use a thing called Skin Britener to etch aluminum before painting, which smelled like phosphoric acid. We also found it to work well on steel parts.

I have been using Rust Bullet for a year now on some badly rusted areas. There is no sign of the rust returning at this point. I can't imaging that it will never begin to fail, but so far it is hanging in on areas that see a fair amount of moisture. Like my steps and battery shelf in the engine compartment.

Bill G