I've primed an interior metal door in my condo with oil-based Zinsser Cover Stain. It was an absolute joy to use - I can understand why it comes very highly recommended as a primer.

I started with a brush and found it left heavy brush marks, something I have read others complain about with Cover Stain. I then moved to a mini-roller and got better visual results.

After 2 coats it looks great but is rough to the touch. I know a light sanding will smooth it out nicely. But should I need to sand? Will an enamel topcoat smooth it out without sanding? And, finally, any recommendations for enamel brand/type? (Rustoleum, oil, latex?).

Thanks in advance.