Personally I would use zero rust instead of POR15. POR15 takes a bunch of steps to get it on right, a lot of prep work. It not a "just one chemical" application. You have to buy several "stage" chemicals to do it right. Zero rust, all you have to do is get the grease,oil, dirt, and scale off, and apply the stuff. You can put the stuff right over rust. You can top coat it if you wish, or leave it as is. It comes in black and red, $80 a gallon. I put two coats on a cruiser frame, inside and outside the frame rails, after steam cleaning it, the stuff is very durable.
I am using it again on my current buildup, same application on the frame, and I am going to use it underneath body parts.
i agree with Ranger on this one...POR-15 is a lot of work to do right...Zero Rust is good stuff www.zerorust.com the stuff stands up good. takes long time to dry. I also like the finish a lot better when Sprayed on. My brothers 68 VW beetle was sprayed with it this summer and he drives the thing everyday and it is holding up good. Also I sprayed my cruiser frame/fender wells with it. Some of the guys in our club also just spray Rustoleom on there trucks once a year and be done with it. But they are the once cutting and welding to there trucks every other weekend too...
I just had my frame sandblasted and sprayed with POR-15 - this stuff is tough! Like everyone says - it ain't easy. Topcoating is a trick - POR-15 dries rock hard and the tech support folks told me you probably should "rough up the surface" (they suggested a scotchbrite pad) before topcoating -- especially if you didn't apply the topcoat within 3-4 hours of applying POR-15. Also, POR-15 contains isocyanates - from what I've read you definitely don't spray this stuff without a fresh air mask/source. Good news it goes on with a brush/roller very well and does not leave brush marks. Bad news it is UV sensitive - I know, I left my frame out side for about a week in direct sunlight and started to see a very slight haze effect appear. POR-15 folks say this will not affect integrity of the product just the cosmetics - thus the need for a topcoat. I applied their Chassis Coat Black product and am happy with the results - this is better applied with a spray than with a brush.
For what its worth- I tried a "test" before I went with the product. I applied some POR-15 to some very rusted steel about 5 months ago - the piece has sat outside in the weather ever since and it looks as good as new - no blistering, etc. Just hope it performs that well on my frame!
I would consider the zerorust for a new/fresh surface. The POR 15 is intended to bond to existing rust, so once this is removed, your results diminish.
I have used the POR 15 on several areas of my cruiser, some with better results than others. If the prep or surface isn't just right it will bubble and peel right off. This was my experience on a freshly sandblasted bumper that I followed the directions on. Their website has the prep procedures for the products and would be a good starting place when deciding.
2 years later I just spray bomb the frame when I want to touch it up. Holds up fine for a vehicle that sees NO daily road use, and no road salt.
Does anyone have any experience applying this to an assembled frame/body, as opposed to a stripped frame? Seems like a big headache, but can it be done, or is it not even worth looking at. What about coating over threaded holes in the frame.
I can't see coating the frame in it's entirety with everything attached, but it would be nice to get some of it coated. Some is better than none right?
I have used POR-15 on my '72 Blazer suspension/frame. It is quite a bit of work to do correctly: clean, metal prep, POR-15, topcoat. Plus, they're pretty proud of that stuff and not exactly giving it away ($$). Now that I've used it on a few things, I won't use anything else. It has held up very well on my front steering/suspension components. It made some rusty nasty looking parts like new. I don't know that I would use it on freshly blasted pieces as all that I have read suggests that it actually bonds better to rusted surfaces. I really like that you can brush it on and it has a smooth finish. I generally coat it with Chassis Black for anything that will see UV. Get this on your skin and you're gonna have to wait till you grow a new layer because it will not wash off. Tough stuff.
From all the research I have done it seems that por15 is more for sandblasted or rusted metal. I went with Zerorust for my undercarriage and frame because I am not going to sandblast just clean up the previous flaking pieces of undercoat and pressure wash the best I can. The guys at zerorust told me that I would be fine as long as I knocked off all loose rust and scale. They also reccomended using TSP to clean it before starting to paint. Plus Zrust is much cheaper than Por, I got mine for like $30 gallon, also bought a spray can of clearcoat they sell to do my rims in the stuff. www.zero-rust.com is where I bought it.