On Por15, yes the 3 steps are necessary to guarantee good adhesion (sometimes you can get away with the paint only but it is hit and miss). RustBullet is a similar product but is single step: http://www.rustbullet.com/ProductCart/pc/viewCategories.asp?idCategory=120

As for color; Por15 is available in black, grey or silver (black is most common); RustBullet is silver/grey, you can top coat either one with whatever color you want. Oil based Rustoleum makes a relatively good top coat and is available in many colors, you can also use Dupli-color, etc. for a top coat. Just make sure to read the instructions on which ever product you use about time between coats and time needed to cure before applying a top coat.

For either Por15 or RustBullet you must do at least 2 coats because these products off-gas CO2 which creates microscopic pin holes in the 1st coat which the 2nd coat then seals.

Undercoat can do as much harm as good. initially it offers good protection but overtime as it degrades it can trap water behind it and cause more rust. If you use good paint and make sure to touch up any chips/scratches you should be good.

 

Thanks for the info. How necessary do you think this is? I've got a 97 it has some rust but nothing serious. Should I just undercoat it for now? Or would it be smarter to spend more and go with something like this POR-15 ?

 

If you're going to do anything go the POR15/RustBullet route. These will seal and stop the rust, you should never just undercoat without treating the existing rust first, it will only hide the problem and allow the metal to continue to decay under the undercoat (the same goes for body filler). You can undercoat over top of POR15/RustBullet, etc. to provide extra protection but as I mentioned earlier even with this you have to keep an eye on it because it can trap water once it starts to become loose/breaks down.

Unless you have access to a heated garage I'm not sure how much you will be able to get done now since most of these products require a temp of 50F or above, but I would recommend taking care of any rust in the spring and definitely before next winter, unlike newer cars 90s Jeeps are not made with galvanized steel and minor rust can turn into a major problem pretty quick if left go.

If you need something on the cheap, Rustoleum brush on rusty metal primer and brush on oil based enamel is ok but POR15 and RustBullet are far superior products and will last much longer.

 

Don't do much treatment on the rust if you are going to use POR-15. It is designed for use on rust (name is Paint On Rust) and does not adhere as well to clean metal.

 

Check out KBS frame coater i used it on my jeep frame it's kind of like por15 two coats of rust sealant and a top coat it came in a kit I think the website is www.kbs-coatings.com

 

Thanks I'll check that out. What is the easiest way to do it exactly? like I said Im learning. Did you jack it up and take all 4 tires off or did u just get up underneath and paint it on?

 

My frame was so bad I replaced it so I started with a stripped frame and sandblasted it but if your doing it with the jeep together it will make it alot harder on you but you will have to figure out how to clean or degrease the frame and probably brush it on , kbs has this coating for in the frame rails its some kind of wax spray which you spray in the frame rails , you just stick the wand in any holes on the frame and spray it in which is good because these frames rust from inside out , also if you think something in a spray can would be easier check out Eastwood.com they have the paint in a spray its like por15 and kbs I was going to use that but went with kbs because I could get a whole kit cheaper and I wanted to brush it on so I could put it on thick but all of these coating will tell you a sandblasted frame is the best to start with unless the whole frame is tightly rusted no paint left or you will have to sand it then degrease it then paint it and do not get any of these paints on you because it doesn't wash off I got a cheap painters suit and gloves from Home Depot , so if you have to do it with jeep you need to get as much out of you way as possible

 

My frame was so bad I replaced it so I started with a stripped frame and sandblasted it but if your doing it with the jeep together it will make it alot harder on you but you will have to figure out how to clean or degrease the frame and probably brush it on , kbs has this coating for in the frame rails its some kind of wax spray which you spray in the frame rails , you just stick the wand in any holes on the frame and spray it in which is good because these frames rust from inside out , also if you think something in a spray can would be easier check out Eastwood.com they have the paint in a spray its like por15 and kbs I was going to use that but went with kbs because I could get a whole kit cheaper and I wanted to brush it on so I could put it on thick but all of these coating will tell you a sandblasted frame is the best to start with unless the whole frame is tightly rusted no paint left or you will have to sand it then degrease it then paint it and do not get any of these paints on you because it doesn't wash off I got a cheap painters suit and gloves from Home Depot , so if you have to do it with jeep you need to get as much out of you way as possible

Thanks that's helpful

 

POR15 is super expensive. Personally I prefer to use a wire wheel on a drill to clean off rust, then use a good metal primer like Rustoleum primer, then paint. Eastwood.com makes specific paint for frames, and it's very tough. It's called Chassis Black and it almost has a rubberized quality to it. Goes a long way and is much cheaper than POR15. Paint should last 10 years. Are you going to own your Jeep longer than 10 years?

 

Eastwood makes some good stuff, such as their rust encapsulator and internal frame paint. Application is easier but not sure of longevity unless topcoated. Prep is key for any paint product. You may get away with out using their Metal Ready for POR on rust but you still need the Marine clean to get rid of dirt and any oil type residue. Bare metal needs both. Metal ready is an etching product that creates teeth for the paint to grab hold of, since there is no old rust to grab.
Going with just a run of the mill primer (like rustoleum) and top coat will last a much shorter time because they don't have the sealing properties these epoxy or urethane based products do. Rust needs air and moisture to thrive so you need something to seal these both out. I've even read that some "primers" will act like a sponge around moisture because they are only formulated to grab a surface, not seal it, they let that up to the topcoat.

 

I read a lot of stuff online for hours and decided to go with the Rust Bullet kit.
I ordered the 3 set on amazon that includes Rust Blast (help remove rust first), standard Rust Bullet, and then Black Walnut Rust Bullet Paint. People seem to have great results with Rust bullet and Rust Bullet paint, not a ton of info out there about the Rust Blast, but it can't hurt to try.