Well, since it appears that you are painting track plastics with spray paint I assume you are not going for show finish. Just do a little touch up, you can use the brush or even small piece of paper. Good luck. Remember, when it comes to painting projects like this it's all about prep and patience.
D.
I am actually using a spray gun (w/ compressor) and PPG paint.
Today i went back to the paint supply shop (ABC Supply in Covina, CA) and Danny Hunt is a genius!! He gave me some really helpful hints and i was able to fix my mistake.
In case anyone is interested, here is what I did...
1. dry sand with 600 grit
2. tack cloth to clean up
3. using masking paper, cut a hole the size of the repair area
4. tape the masking paper to the bodywork
5. adjust the spray gun to the lowest pressure and the smallest fan
6. 2-3 coats and good to go!
I'll clear tomorrow after work and then its time to work on the tank.