How to address rusting scratches on my car

[AlanStache]

The roof of my car got scratched up and is starting to rust, I would like to not have to buy a new car because water leaks into the cabin.  What can I do to stop the growth of the rust, preferably something that is lower cost and lower effort?  The car +15 years old and grey so maybe a few layers of duct tape?

[RWD]

Covering it is only going to hide the problem, not make it go away. I think you need to sand all the rust away then primer and paint. If you don't care about how it looks this isn't too hard to do yourself.

[terran]

If you're suggesting duct tape (which I wouldn't do because if anything it would make it rust faster) then I assume you don't really care what it looks like? I'd go with rustoleum paint in whatever color you want. If you want to put in a little more effort to increase the likelihood of it lasting longer you could use a wire brush and some sand paper to get rid of any loose spots and rough things up to give the paint more to stick to.

Edit: RWD is right that the most permanent solution is complete removal of the rust and then painting, but I think rustoleum over the rust should last for awhile.

[RWD]

Rust-Oleum can be a decent option too if you don't want to expend as much effort. They have a product called "Rust Reformer" which doesn't require sanding to get rid of rust.
https://www.rustoleum.com/product-catalog/consumer-brands/auto/removers-and-chemicals/rust-reformer-spray/

[AlanStache]

I am not necessary looking to "fix" the problem but more to prevent this from being the problem that makes me have to get a new car. 

Rust Reformer Spray looks like a good option, thanks RWD.

[Tester]

How many years do you want to keep it?

I repaired some rust on my car, sandpaper of different griys, primer, paint and did not do the clear coat anymore.
It looks fine after two years.

You can find a ton of youtube videos on how to do it, I would say it is easy...
Btw, if you want, you can find paint to match your car based on year, make, model, paint color.
Forgot the site I used for thay, but I think there are more...

Edit: looked at the picture... There is a bigger surface than I had so more sanding, but I think it should still be doable relatively cheaply, around 200 usd...

[MilesTeg]

The roof of my car got scratched up and is starting to rust, I would like to not have to buy a new car because water leaks into the cabin.  What can I do to stop the growth of the rust, preferably something that is lower cost and lower effort?  The car +15 years old and grey so maybe a few layers of duct tape?

A rust converter (chemical that converts rust to a black inert substance) is your best bet. Pretty toxic shit though read the label and follow directions!

https://www.amazon.com/Rust-Oleum-Automotive-248658-10-25-Ounce-Reformer/dp/B003HG48AC/ref=sr_1_2?dchild=1&keywords=rust-oleum+rust+converter&qid=1620105642&sr=8-2

[MilesTeg]

I am not necessary looking to "fix" the problem but more to prevent this from being the problem that makes me have to get a new car. 

Rust Reformer Spray looks like a good option, thanks RWD.

Have you looked _under_ your car lately? Rust on a body panel from scratches isn't something that's going to "break" your car unless you are in a bad climate for rust. But if you're in a bad climate for rust you're likely going to have a rotting frame/unibody.

Always wash your car's undercarriage frequently...

[Tester]

OP, when you are done please let us know how you solved it and the cost.
It would serve others with similar problems.

[WhiteTrashCash]

Use POR15 paint on the rust spots and then paint over it with touch-up paint in your car’s color which you can get off of eBay. That will prevent the rust from spreading and seal it off.

[AlanStache]

I have ordered a can of rust-reformer-spray, will post some after pictures, but I cant say that painting to match the body color will be anywhere near the top of the list.  Most of the paint is in various stages of fading so not sure I could match it and have it look rigth. 

Frame & under side: we dont salt the roads here and I make a point to not drive through brackish water.  Will still make a point to check this spring. 

[nereo]

PTF. I’ve got a similar situation with my 15 yo vehicle...

[AlanStache]

It has been a few weeks since I treated the roof and over all it worked well.  There are one or two small spots I think will need a touch up.  Having a black roof is a lot less noticeable than I expected, not sure how much better a jolly roger stencil would make it look.  The 'After' pic was taken today, about 3 weeks after paining.  It was a bit windy the day I did the painting and that made it hard to apply smooth long passes and resulted in the uneven tone.