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Question on eliminating rust from roof

Old Apr 23, 2020 | 08:40 AM
  #1  
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From: El Valle
Year: 1999
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Default Question on eliminating rust from roof

I started sanding down a couple of really small surface rust on the roof of my XJ. As I sanded down the area I noticed more and more rust. Not really deep though but a lot under the paint. I stripped all the paint off so how can I get rid of the remaining rust before I prime?
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Old Apr 24, 2020 | 07:10 PM
  #2  
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Year: 1995 (YJ)/1998 (XJ)
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When I painted my Jeep, I would use a drill with a wire brush attachment and go spot by spot.

used a sander to take off the rough outer rust the went over it with wire brush then a finer grit sand job finished off with an isopropyl wash. Prime and paint

It can be overwhelming when you dig into it. Take it by quarters of the roof and prime whatever you clean ASAP. Don’t wanna leave bare metal exposed longer then you have to. I was pretty limited to an angle grinder and my drill. A palm sander my be a good choice for wide open area like the roof for some precision sanding.

time and effort is the only way I know of to do it right. A sand blaster would work too but pricy
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Old Apr 26, 2020 | 06:57 AM
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you can use POR15, but it's pricey and very hard to get off your hands, so old clothes and gloves are a must. POR15 is a two part epoxy and only comes in black, but you will have to paint over it anyways, so you can paint body color once it cures. it will never rust again, and is hard enough to resist chips, even from a hammer. lol but you will never ever be able to sand that chit off later.

or use a cheaper rust inverter/converter style paint to paint over those rust spots, then paint with color match.

or even cheaper and easier, just use primer/paint, but those rust spots may come back even worse, unless you eliminate the rust totally. (wire wheel on a drill/grinder)
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Old Apr 26, 2020 | 07:30 AM
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Originally Posted by caged
you can use POR15, but it's pricey and very hard to get off your hands, so old clothes and gloves are a must. POR15 is a two part epoxy and only comes in black, but you will have to paint over it anyways, so you can paint body color once it cures. it will never rust again, and is hard enough to resist chips, even from a hammer. lol but you will never ever be able to sand that chit off later.

or use a cheaper rust inverter/converter style paint to paint over those rust spots, then paint with color match.

or even cheaper and easier, just use primer/paint, but those rust spots may come back even worse, unless you eliminate the rust totally. (wire wheel on a drill/grinder)
2 part epoxy?
The stuff I use is not. You have to prep but the POR 15 itself you use right out of the can. And does come in different colors.

https://www.por15.com/POR-15-3-Step-Stop-Rust-System

It is UV light sensitive so a black will eventually be an ashy gray. But does not effect it otherwise.
I always use it under the Jeep so I don't care. And I never top coat it.
But why some people top coat. Appears that it does not really matter what you use for a top coat.
There is one thing that I came across though. Using bed liner on the gloss black one.
Appears that could be an issue. Not sure if because it is shiny and scuffing it up would make it OK or
if it is something else. Also the consensus seems to be to spray it on while the POR 15 is still tacky.
Like they tell you to do with a regular top coat.
My point is take the 2 minutes to think it through so that what you do now will not effect what you want to do later.
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Old Apr 27, 2020 | 07:03 AM
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Originally Posted by Ralph77
2 part epoxy?
The stuff I use is not. You have to prep but the POR 15 itself you use right out of the can. And does come in different colors.
ok, they must have changed it. i know it used to be two parts, and only black. but that was a few years ago.
they still have a two part urethane, dunno if it's just a canadian thing, but it is available, and in a few different colours.
actually, they have many new products, that they didn't offer years ago. pretty cool too. didn't even know. gonna use some of their other products, now that i know what all they have.
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Old Apr 27, 2020 | 07:12 AM
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Originally Posted by caged
ok, they must have changed it. i know it used to be two parts, and only black. but that was a few years ago.
they still have a two part urethane, dunno if it's just a canadian thing, but it is available, and in a few different colours.
actually, they have many new products, that they didn't offer years ago. pretty cool too. didn't even know. gonna use some of their other products, now that i know what all they have.
They are constantly coming out with new stuff.
I started with the Starter Kit maybe 5 years ago. Figured I would "play" with it and see what it was all about.
So I did a bunch under the Jeep. Know how the seams like to rust in the floor where they meet?
And did a few other things. Prepped the best I could.
So that little 4 oz can goes a long way. Farther then you would think.
So I had some left over. So without any kind of prep just wasted it on places under the Jeep.
One of the things I did was the heat shield for the gas tank. Got up as far as I could under there.
No prep, wire brushing. Nothing. Well 2 years later I dropped it to install a gas tank skid.


Now granted I do not drive a much. But looked like the day I did it.
I used the POR 15 Hi Temp paint on my new Walker exhaust. That did not fair to well though.
Frankly I am blaming it more on user error though. I just cleaned up everything with brake clean
and went at it. Most of the paint got "sandblasted" off under the Jeep.
All in all I am very happy with POR 15 stuff.
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Old Apr 28, 2020 | 10:27 PM
  #7  
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Another option is a product called Ospho:

https://www.amazon.com/Ospho-605-Metal-Treatment/dp/B000C02CDG



The marine industry uses it all the time to convert rust into a paintable primer. I think its iron phosphate when its done. Works well on boats.

Or another product called "Naval Jelly"

https://www.amazon.com/Loctite-Naval-Dissolver-16-Fluid-553472/dp/B000C016OC



Same idea/concept.
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