Depending on the manufacturer, usage and paint formula, oil-based primers require one to 24 hours of drying time before the next coat can be applied. The drying time is affected by indoor and outdoor temperatures, humidity levels and the thickness of the coating.
Several fast-drying, oil-based interior primers, such as Kilz Original, require only one hour of drying time. Other brands, such as Benjamin Moore, require up to eight hours of drying time. The majority of exterior oil-based primers require 24 hours of drying time in temperatures above 45 degrees Fahrenheit and 48 hours when temperatures range from 35 to 45 degrees Fahrenheit.