Re: re-painting a cowling
I just realized it was an engine cowl. Ok so here is your approach.
First, remove from motor, remove sticker and sticky residue (3m adhesive remover or similar) and clean the cowl with a soap that is suited for degreasing.
Scuff the cowl with 220 sand paper
blow off with compressed air, and wipe with a prep sol (or the solution i use 3:1 - water:denatured alchohol (i like this because it evaporates quickly and does not leave streaks) with a cotton cloth or tack cloth
If you have nicks or scratches you wish to fix this is the time to do it as the filler will soak up the primer some what and once the primer is down you will be able to see if the repair needs more filling.
Next coat the the fairing in either gel coat (spray) or more simply with a thick filling primer. 2 -3 coats as directed on the can of primer. you can use any primer you like, epoxy primer or something else but i would suggest a urethane based primer that is specific for filling and sanding (only if the glass was showing through the paint prior to starting) otherwise you do not need a sanding primer.
when the primer is cured wet sand it with 320 sand paper and then 400 if you wish but is not really nessesary if you use a poly paint as if fills voids well.
again blow it off and wipe it with solution
mix paint by manufactures directions and spray with 2-3 coats,
I assume you know how to spray and set a spray gun but if not feel free to get a hold of me and i will help you get set up
Also where ever you get the paint ask for a spec sheet for the primer and for the paint also called tech sheet or msds sometimes, this is all the detailed info that will help you when spraying and knowing drying times and compatibility of products etc.
good luck