How to get rid of rust spot?

[Yousend]

I have a minor rust spot on my roof that I would like to get rid of before it spreads.

I spent 5minutes on Google and apparently I have to sand it down to the metal and repaint it. I do have some touch up paint, so that would be an option.

Does anyone have tips or just any insights on getting rid of the rust?

I can't get the image to work, so here's the link.
http://imgur.com/a/EtMCW

[ls1ac]

In the picture it looks like the rust has already spread under the paint on both sides of the chip. You will have to remove the bubbled paint then clean. A Dremel tool will work well, for DIY a rust converter instead of a normal primer works well, then paint.

[MuseChaser]

Get the starter package of POR15 products. Nothing else will stop rust. You'll need to paint over it and it'll take some work to get your touched up spot to blend seamlessly (an impossibility in my experience, but I stink at body work), but when faced with a choice between a near-perfect finish with the almost certainty of returning and increasing rust, or an imperfect job with rust pretty much eradicated permanently.. well... I'll take the cure over the bandaid any day.

[Tcoat]

Originally Posted by MuseChaser

Get the starter package of POR15 products. Nothing else will stop rust. You'll need to paint over it and it'll take some work to get your touched up spot to blend seamlessly (an impossibility in my experience, but I stink at body work), but when faced with a choice between a near-perfect finish with the almost certainty of returning and increasing rust, or an imperfect job with rust pretty much eradicated permanently.. well... I'll take the cure over the bandaid any day.

Surface rust can easily be stopped just by sanding it off and coating it so that moisture can no longer get to it. Rust from behind or integral to the metal (almost unheard of now) is the stuff that can't be stopped easily.

Just sand it and coat it and all will be fine.

[Yousend]

Originally Posted by ls1ac

In the picture it looks like the rust has already spread under the paint on both sides of the chip. You will have to remove the bubbled paint then clean. A Dremel tool will work well, for DIY a rust converter instead of a normal primer works well, then paint.

Thank you, I'll try that. How long would I have to do this? Obviously the longer I wait, the worst it gets, but I may be unable to do this until the weekend if the weather does not behave. It should not be too late, correct?

[MuseChaser]

Originally Posted by Tcoat

Surface rust can easily be stopped just by sanding it off and coating it so that moisture can no longer get to it. Rust from behind or integral to the metal (almost unheard of now) is the stuff that can't be stopped easily.

Just sand it and coat it and all will be fine.

I wish I could agree with you, but it just hasn't been my experience. I let a small paint chip go for a year or so on the door of my '93 325i. Once the spot started rusting and the associated blistering had grown to about the size of a quarter, I sanded it down to what looked like bare metal, used a little spray-on "rust converter" of some kind, then primed and painted it. Within six months the rust was back worse than ever. Same story on a couple door dings on our '99 ML430.

There's a reason body work shops, at least in our area, will not warranty any work done on rust. POR15 is the only stuff I've found that will stop it. I live in the Lake Ontario lake effect snow belt (actually, just slightly below the worst of it, but we still get hit a LOT) and they use a TON of salt here. Maybe it's not quite as bad, salt-use-wise, up where you are, T, and that could explain our different experiences. If your area DOES use a lot of salt, too, then I'm not sure how else to explain my bad luck with rust compared to your experiences. If I recall correctly, I don't think either one of us are particularly diligent when it comes to washing our cars...

Yes, modern cars do MUCH better with rust prevention than cars did a few decades ago.

[Tcoat]

Originally Posted by MuseChaser

I wish I could agree with you, but it just hasn't been my experience. I let a small paint chip go for a year or so on the door of my '93 325i. Once the spot started rusting and the associated blistering had grown to about the size of a quarter, I sanded it down to what looked like bare metal, used a little spray-on "rust converter" of some kind, then primed and painted it. Within six months the rust was back worse than ever. Same story on a couple door dings on our '99 ML430.

There's a reason body work shops, at least in our area, will not warranty any work done on rust. POR15 is the only stuff I've found that will stop it. I live in the Lake Ontario lake effect snow belt (actually, just slightly below the worst of it, but we still get hit a LOT) and they use a TON of salt here. Maybe it's not quite as bad, salt-use-wise, up where you are, T, and that could explain our different experiences. If your area DOES use a lot of salt, too, then I'm not sure how else to explain my bad luck with rust compared to your experiences. If I recall correctly, I don't think either one of us are particularly diligent when it comes to washing our cars...

Yes, modern cars do MUCH better with rust prevention than cars did a few decades ago.

LOL I live dead center of all the great lakes. We are the salt kings. Can't explain the difference in results though since I have never had an issue with surface rust returning even on my 50s cars restoration projects. Mind you I have never dealt with either of the cars you mentioned before so maybe something different there.

[ls1ac]

The sooner the better, but a day or two will not matter.
I agree with Tcoat, I have many fixes that have lasted as I work primarily on old cars. Preparation and cleanliness is key to getting good results. Usually not being aggressive enough in preparation is the problem. We want to think that the less we sand the better and will leave an untouched ring around the edge is ok, not so.
POR-15 is just one of the many good converters.

[Yousend]

Thanks guys, I did grind it down to the metal, used a rust converter and painted over it. It turned out to be a bit wider than I expected it to be, but it's better than having the car rust down.

The paint isn't uniform and it's slightly off-color. It's not very noticeable unless you are close up or looking for it.

Thanks to you guys I don't have to burn it with fire.

[cat94]

Originally Posted by Yousend

Thanks guys, I did grind it down to the metal, used a rust converter and painted over it. It turned out to be a bit wider than I expected it to be, but it's better than having the car rust down.

The paint isn't uniform and it's slightly off-color. It's not very noticeable unless you are close up or looking for it.

Thanks to you guys I don't have to burn it with fire.

If it isn't too much trouble, can we see an after picture

[Yousend]

Originally Posted by cat94

If it isn't too much trouble, can we see an after picture

For sure, I forgot to do that last night. I had other stuff to do immediately after the process so I never got around to it. I've seen my fair share of body work threads to know that before-during-after pictures are necessary!

I'll edit this post once I get back home in a couple of hours.

[Yousend]

After grinding it down


Close up


A bit further out



Not the best lighting, but I was too lazy to move it at that point.

Now I only have a minor issue, I guess I put too much rust converter/didn't clean it up well enough that makes it super obvious. There's a brown spot around my new paint job! I assume that'll go away the moment I clean it properly?

[Scrappydoo]

Looks OK. Man on a flying horse isn't going to notice that.

[Tcoat]

Originally Posted by Yousend

After grinding it down


Close up


A bit further out



Not the best lighting, but I was too lazy to move it at that point.

Now I only have a minor issue, I guess I put too much rust converter/didn't clean it up well enough that makes it super obvious. There's a brown spot around my new paint job! I assume that'll go away the moment I clean it properly?

It may or may not clean up (how is that for a clear answer) depending on if it stained the paint or is just sitting on it. If you use a very small brush and put another coat of paint inside just the low spots of the repair it will be=lend in even more. You will still know it is there but 98% of other people will never spot it