POR 15 in weather contact areas. I use rustoleum in places inside the car where the elements are not likely to affect.
I have used both POR 15 and KBS Rust Seal and prefer the KBS as it just seems to lay down and coat the metal a little better.
I played with the por for years on different projects...eventually it will break down and start to rust, sand blasted some wheels, then por 15, still got the wheels lotsa rust coming up from underneath , I have had better luck with rust converters, phosphoric acid , epoxy primer ...will never waste the money on Por stuff again.....
I don't have alot of money. I do have time. I would rather cruise with the extra gas money. I never have waited long to see if rust is growing on any of the for mentioned processes. They all work. Flip a coin. I say, I would rather on that gas money be crusing than sitting and looking at my rust prevention, preventing. Dig?
it's pricey, but you can't go wrong with POR 15. I did the inside and underside of my body along with most of the chasis going on 10 years ago. still holding up great.
Rustoleum is crap. Very low solids. There are better paints to use if that's the way you want to go. POR or Rust-mort are a better route. Rust-mort is made by SEM. They have a lot of good automotive products.
I'll tell you two things about POR-15. 1. It doesn't stand up to UV light at all well. 2. Some (most) top coats don't adhere to it well. I did the underside of my '51 Ford 25 years ago, and it has held up great. I recommended it to a friend to do the plow frame on his truck. After a couple of years it had deteriorated badly, and he came down on me hard. The difference? The underside of a car doesn't see UV while a plow frame does all the time. POR makes two products; a UV blocking finish coat, and a product that prepares a POR-15'd surface for most ordinary finishes. It's like anything else; it's not a do all, end all product; it has it's specific uses where it works very well. Use it incorrectly, and you're in for problems. Luckily for us, POR makes additional products for the instances where the product alone is not the best solution. I'm not a shill for POR-15, I just crawled under my '51 and it still looks great. Some times these products are not the panacea that we would like them to be; it usually takes a little more effort.
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