Rustoleum enamel not glossy

[quadracer92]

I am painting my father's tractor for him (it desperately needs it), and am having problems with the basecoat's finish on the rear piece. I am using rustoleum gloss oil based enamel thinned with mineral spirits. The hood piece has come out great, very glossy and smooth. The rear fender piece has a flat, rough look/feel to it. I'm not sure what I am doing wrong as i have painted the two pieces identically. My only idea is that some overspray hit the rear piece and is acting like a dusting coat that is taking away from the gloss?

 

[TAZ]

That's what it sounds like to me. Possibly you finished the tail piece first. Then went and finished the front piece. The overspray from the front piece got on the rear piece and made it rougher and a little duller. Sounds like you may have to lightly wetsand the rear piece (possibly with 1000 or 1500 wetsand), then respray some clear.
Or, if you are just spraying it as a single stage paint (no clear), you will need to redo the color coat.