Spray the Pattern Prima coat and Hi-golss coat

Hi Sir:

I am using your Pattern coat.I bought to you the GelCoat Spray Gun. This one brings the general purpose nozzle 3/16" or 4.7mm.

My question is: Can this nozzle be used to spray gelcoat as well Primer Coat for patterns?

The viscosity of the primer coat is not thick, so I guess 4.7mm the is not suitable. But I want get a right answer from you.

When use spray gun for Primer Coat and High-gloss and GC50, Alwasy Use 25% of acetone to dilute, right?

I want to get your reply quickly, thank you!