Fixing rust spot

Status
Not open for further replies.
jeepman3071

jeepman3071

Joined
Apr 15, 2010
Messages
10,284
Location
Connecticut
Not sure if this goes under the detail and wax category...

Yesterday I noticed a rust spot on the roof of my Jeep. The Jeep has 143k miles, and the rest of the body is spotless. I'm guessing there was a rust bubble here, and the paint flaked off a few days ago, because it wasn't there a month ago.

Here are some pics:

photo_2.jpg

photo_1.jpg

photo_3.jpg


How should I go about fixing this? I'm a college student, so unless its absolutely necessary I'd like to avoid a body shop. It is on the roof so I'm not too concerned about looks, I'd rather just get rid of the rust and prevent it from coming back. My dad said to sand it down (I have a dremel with sanding disk), use primer, and then paint it. I do have a can of factory matching paint I could use, as well as a can of clear coat. Any suggestions? How should I prep? What kind of primer should I use?

Thanks for any help!
 
"My dad said to sand it down (I have a dremel with sanding disk), use primer, and then paint it. I do have a can of factory matching paint I could use, as well as a can of clear coat. Any suggestions? How should I prep? What kind of primer should I use?"

Do sand it down. Do feather out the edges into the good paint. Buy decent primer (preferably etching). It's not hard to do, just hard to do well. But maybe that's not important on the roof.
 
Originally Posted By: bepperb
"My dad said to sand it down (I have a dremel with sanding disk), use primer, and then paint it. I do have a can of factory matching paint I could use, as well as a can of clear coat. Any suggestions? How should I prep? What kind of primer should I use?"

Do sand it down. Do feather out the edges into the good paint. Buy decent primer (preferably etching). It's not hard to do, just hard to do well. But maybe that's not important on the roof.


I have a wire wheel attachment also if that would work better for the edges. I'm not so concerned about it looking nice as I am about it holding up. Would self-etching primer be better than rusty metal primer? I'm guessing I should get rid of ALL the rust and get down to bare metal?

Thanks for the input!
 
Originally Posted By: ClutchDisc
Gray plastidip. Cheap (about $6-$9) for a can, good to go. It's the roof anyway, nobody will see it!

Here is the link for it on amazon. I would just sand it down, no need for primer or really any prep, just put a generous amount of the coats of plastidip on there, and you'll be good to go!


Thanks for the link. Isn't Plastidip that stuff that can just be peeled off though? How well would that hold up?
 
I would use a wire wheel, then some brand of phosphoric acid (Naval Jelly), some primer and paint.

This looks to be coming from the outside. A lot better than rust coming from the inside out.
 
Originally Posted By: jeepman3071
Originally Posted By: ClutchDisc
Gray plastidip. Cheap (about $6-$9) for a can, good to go. It's the roof anyway, nobody will see it!

Here is the link for it on amazon. I would just sand it down, no need for primer or really any prep, just put a generous amount of the coats of plastidip on there, and you'll be good to go!


Thanks for the link. Isn't Plastidip that stuff that can just be peeled off though? How well would that hold up?

You can peel it off, but it doesn't just peel off on it's own. My dad and I have used plastidip for a lot for rust repairs and it's held better than anything else. I did the primer, paint, and then clear coat and it was rusting through in a few weeks. Paint is hard to dyi. I would give the plastidip a try.
 
I think a wire brush would probably work better, though the one on a dremel might take awhile. If sanding I'd skip the dremel and do it by hand.

I would get down to bare metal and don't use a rusty metal primer, use an etching primer.
 
I also have an angle grinder with a wire wheel and sanding flap disc. I'm thinking a dremel might be more precise though.
 
You need to chemically neutralize the rust with something like Naval Jelly, then apply touch-up paint on top to protect the surface. I've used this process before and it works very well.

Naval Jelly is at most auto parts or home improvement stores for $8 or whatever, and touchup paint is another $8.
 
As Donald and dparm have said use a rust remover, aka phosphoric acid, to get rid of rust you can't sand out. Don't use those rust inhibitors (stuff that just seals rusted areas).

Sanding, unless removing a lot of material, will only get you so far if the material has pitted. The rust hides down in the pits where the brush or sandpaper has a hard time reaching. Paint over it and sooner or later it'll come back.

Keep applying and washing off the naval jelly until all the rust has turned black and fallen off, make sure the steel is all gray also.

If your impatient Home Depot sells a concrete etcher that's concentrated phosphoric acid. I use that instead of naval jelly as it's much faster acting. Very quick and easy to use especially on the horizontal surface of a roof.
 
I stopped a rust spot in its tracks with this:

POR15

IMG231.jpg


P1020798.jpg


No signs of it coming back after a year and one brutal, salty, Winter.
 
many years back on the spike channel auto shows, they showed POR
Paint over rust, it was a black paint that you just paint over the rust and it converted rust to paintable surface.
obviously you brush off the loose stuff and then por.

I wonder if POR 15 is similar?

I have a few spots on my ridgeline I need to take care of also.
 
Originally Posted By: stockrex
many years back on the spike channel auto shows, they showed POR
Paint over rust, it was a black paint that you just paint over the rust and it converted rust to paintable surface.
obviously you brush off the loose stuff and then por.

I wonder if POR 15 is similar?

I have a few spots on my ridgeline I need to take care of also.


POR 15 was the product featured on the show.
 
Originally Posted By: gomes512
As Donald and dparm have said use a rust remover, aka phosphoric acid, to get rid of rust you can't sand out. Don't use those rust inhibitors (stuff that just seals rusted areas).

Sanding, unless removing a lot of material, will only get you so far if the material has pitted. The rust hides down in the pits where the brush or sandpaper has a hard time reaching. Paint over it and sooner or later it'll come back.

Keep applying and washing off the naval jelly until all the rust has turned black and fallen off, make sure the steel is all gray also.

If your impatient Home Depot sells a concrete etcher that's concentrated phosphoric acid. I use that instead of naval jelly as it's much faster acting. Very quick and easy to use especially on the horizontal surface of a roof.


What would you consider Loctite Extend? Sealer only? treat & seal? treat only?
 
Cutting and welding in new metal with appropriate rustproofing on the backside is the only correct repair. Anything else may or may not last.
 
Originally Posted By: exranger06
Originally Posted By: stockrex
many years back on the spike channel auto shows, they showed POR
Paint over rust, it was a black paint that you just paint over the rust and it converted rust to paintable surface.
obviously you brush off the loose stuff and then por.

I wonder if POR 15 is similar?

I have a few spots on my ridgeline I need to take care of also.


POR 15 was the product featured on the show.


There are 2 steps of prep and one of paint for the POR15 process, the first of which is phosphoric acid.
 
Status
Not open for further replies.

Similar threads

A
Will flushing rocker panels cause more rust?
Replies
16
Views
1K
JoeDirt41
D
Rear view mirror takes some glass with it - GMT800
Replies
8
Views
298
zzyzzx
H
Rocker panel rust
Replies
11
Views
524
midnightlaundry
G
Best Way To Stop Rust Chevy Van
Replies
11
Views
2K
GMBoy
S
Newer Dodge "Ram" trucks with Rust?
2 3
Replies
44
Views
2K
Hohn
Back
Top Bottom