Your Opinion - Best Rust Preventative Undercoating/Encapislator?

[MarcZ]

I was having a discussion with my paint teacher the other day (sadly the only competent one there) about different "brand name" coatings in the higher prices, such as POR 15 and the lower priced Rustoleum Hammered Finishes. He was saying that the Rustoleum is just as good as POR 15, so I was wondering what you guys think. I do agree that to a certain extent you're paying for a big name, though Rustoleum is a fairly big name, though known for being a cheaper variety.

What, in your opinions, is the best encapislator that stops rust dead or keeps it from forming?

 

[Kamikaze]

Marc,

I disagree with your instructor.

Rustoleum Hammerite paint is a tough product and will stand up to some abuse but I feel the POR-15 is much tougher and durable. I've cleaned up some valve covers other parts used in an engine bay with glass beads in a blast cabinet. With POR 15. I've had to use a very aggressive abrasive to just scratch the surface.

Hammerite also has than unique "mottled" but glossy finish to it but it is not very durable when exposed to sunlight, or heat. The finish becomes dull and dry looking where I've had and seen POR-15 stand up better. Of course POR-15 also has a specific product with UV inhibitors for exterior usage, I feel the PRO-15 is better at encapsulating the rust.

 

[MarcZ]

Thanks for the info. And in his defense, he is more of a painter than a restorer. I still trust him, one of the best teachers I've had.

What do you think then about the cheaper ones like Zero Rust or Eastwood Encapsulator? I'm cheap, can you tell? Well, broke, not cheap. I've heard a few bad things about POR 15 peeling off fairly soon after application. Many say "I used it once and will never use it again because ....".

 

[Harveyb]

I vote for the zero-rust,have heard a lot of complaints about por.

 

[BTTB71SS]

I use Zero Rust and am very happy with it so far.

 

[Rick WI]

First lets establish that there is no better surface for primer/paint than clean bare prepped metal. Nobody in the industry that paints products paints over rust. If there was a magic coating that really and truly work to prevent further corrosion industry would adopt it, eliminate the cost of 7 stage washers, phosphate coatings and ECoat and slather on some the magic elixer.

With that said I agree with your instructor, if you are going to cover up rust, Rustoleum rusty metal primer works just as well as anything else out there.

 

[GetMore]

Regarding clean metal vs. rusty metal, I think that's the reason POR-15 sometimes peels off too easily. It probably doesn't "bond" with the metal like a good paint, it relies on seeping into the nooks and crannies to hold on. FWIW, the way it works at preventing rust is by forming a barrier impervious to air. If you starve rust of air it can NOT spread.

 

[rindoze]

I use the POR patch and that stuff kicks ass. So yeah it's awesome

 

[MarcZ]

I absolutely agree about getting to clean metal. But as we all know, that isn't always possible.

Thanks for the opinions. I think I'll try the Zero Rust line.

 

[68400BIRD]

Like mentioned above por15 works best on a slightly rusty but very sound aged metal. I painted the bottom of my car around 12 years ago with por15. I had the rust look on the bottom of the car but I did not have any rust scabs. I degreased the whole car, scraped any dirt or build up and then metal prepped the bottom of the car. To this day the bottom is in the same shape as when I painted it. Por15 does not stick to clean bare metal very well IMHO it might stick better to sandblasted parts but at that point I would spray a good epoxy primer. If you get some por15 and some rustoleum on your hands let me know which one you get off first. That alone will tell you which one sticks better.