I would not wash with water, because water is absorbed by primer. i used to do that until i got water bubbles under paint. I would blow off with air , auto body tack rag (there is a difference.) then wax and grease wipe and dry with clean white paper towels . tape and wax and grease again and dry . mix paint into gun , lightly pass auto body tack rag just before spray and if need have it handy after base is dry to lightly catch nubs before laying down clear .