Best way to fix tiny tiny rust spot?

I noticed a tiny chip of paint on my roof about two years ago- it was rust colored in the chipped area when I first saw it. Now, two years later, it looks like it is starting to bubble/spread a little bit (see pics) so I feel like I should do something now before it’s too late.

Is there an easy DIY method I can do to fix it? I have a stick of the OEM touch up paint…

Removal all the rust is most important. I’d use a small drill bit (perhaps twice the size of the spot) turning very slowly. Then a dot of primer, let it dry, sand carefully, and a dot of paint.

On a rust spot that small, you want to use an X-ACTO knife to scrape off the rust and loose paint.

http://xacto.com/products/cutting-solutions/knives.aspx

Then once the rust and loose paint is removed, you’ll want apply a rust converter to prevent further rusting.

http://www.permatex.com/products-2/product-categories/specialized-maintenance-repair/body-interior-trim/permatex-rust-treatment-detail

Then apply a non-sandable primer and then the touch-up paint.

This is an option, but using something like this while repairing such a small area comes in real handy.

http://ehobbytools.com/contents/en-us/p1108.html

Tester

I’d be inclined to use a dremel tool, but the important thing is to get it right down to the metal no matter what you choose to use.

I would prime it after removing the rust. After 2 years, the metal is probably pitted. Using a rust converter type primer would transform the rust in the pits to a benign compound and protect the bare metal. Put masking tape around the spot. The tape should be attached to the roof and a few sheets of newspaper. Now you have a spray shield to put the primer on. The primer can be sprayed. Start on the newspaper and sweep over the repaired spot. Don’t stop moving the spray around until the spot is covered. Then top coat with the touch-up paint. I’ve done this before and it works well.

Good directions @jtsanders . The rust has already removed metal by oxidation. If it happens again, a little grease on it to slow the process down till the spirit moves you. Make sure you grind all the rust away, sand and feather the area. Agree. I would apply a rust converter primer as well to bring the level back up then apply a touch up paint. The longer you wait, the more work you need to do. And , the greater the chance rust stain will reappear. In heavy salted areas, the pitting could go all the way through. So as soon as you see nicks, grease it till you can fix it even if it looks like primer is still in tack.