So I need to touch up some small rust spots on the seat tube of my girlfriends teal Centurion Ironman. I was thinking I would just use a small sanding wheel on a dremel tool to pinpoint each spot and then just touch up the spots. Was thinking model paint would work good for matching the color cause I could mix.

Am I going about this all wrong....?

No, you are doing fine. A Dremel may be a bit extreme to clean up the rust spots but it will work. Model paint or nail polish are the usual recommended sources for touch up paint since they come in such an astounding range of colors.

I would not recommend using a dremel to remove rust because you might put swirls in the surface of the metal. Thus use some fine emery paper or SotchBrite pad to remove the rust; then use paint to match, either fingernail polish or enamel model paint as the first poster mentioned.

You can also get touch up paint in auto supply stores.

While true, auto supply stores use paint that matches colors the automotive industry uses, bicycle industry does, not thus a true match would be more difficult to find.

I went to Ace hardware and had them match by sight (they couldn't get the frame onto their matching machine). They made the color and I just bought a small paint sprayer made by Preval to spray the brush-on paint.

https://www.prevalspraygun.com/

What do you guys think of this idea? I'm going to start soon, with the fork first, since I'm about to partially tear down the bike for a Frame Saver application anyway.

To sand down the chipped spots go to one of the big auto parts chain stores and in the paint dept they sometimes carry a small pen shaped device that has little glass strands that protrude like a ball point pen. 3M makes one oddly enough named "Spot Sanding Pen". You just rotate it around on the paint chips and rust spots and it leaves a nice little round clean bare spot roughly about 3mm in diameter. Dab enough paint to fill in the spot and lightly sand smooth when dry.

That sound perfect! Thanks for that.

I was thinking hers was about that year. I havent broken down the serial numbers yet using Sheldon "my hero" Brown's guide though. And yep, its an expert.

I also have a Master that I ride, white and grey marble
one of the gold and pinkish purple experts
a black expert with suntour components
and another Teal expert that was going to be mine at one time.

All beautiful (well aside from my master. its got a few paint scraps. But for $165 im not complaining.)
These go for a bit more than that here in southern california.

Im going to be selling all but mine and hers.

Thanks for all the advice on the touch up everyone. Much appreciated

Searching the forums, it seems here is the best place to ask my question.
I have a Canadian made 86 Raliegh Grand Prix(black) - frame says 'cro-mo Tange 5.' Not a high end bike, but it's good for my conversion project.

There are some rust spots on the frame, mostly around the dropouts. I'm not particularly concerned about its appearance, but I want to stop any more corrosion. I've cleaned the whole frame and took vinegar and a stiff brush to the rust spots. It's degreased and dry.

I'm wondering if I should use a 'rust converter' product on it. I've read that it can dry rather thick, and I'm worried I won't be able to put the wheels back on! Anyone comment on this? I'm also thinking that the dropouts are prone to chipping/scraping and I imagine nail polish wouldn't last long - would the auto or 'hobby store' paint last any longer? There's also a couple rust spots on the seat and chain stays, so I'm thinking of trying a little rust converter on there as a test and see what happens, but any advice prior to this would be greatly appreciated!
Thanks!

I routinely use rust converter and recommend it for both the OP's bike and the Raleigh as well. It makes a great primer before applying any touch up paint. I pretty much ALWAYS use it prior to touch up. The product I use dries black, so for minor touch up on a black bike, I am done once I use the converter.

Thank you, wrk101. Do you find that the converter 'builds up' and is thick?

Only if you apply it thick.

Thanks again! Seems now it's a matter of finding it!