Rapid-drying primers like shellac and lots of water-based merchandise dry much too immediately and become brittle. This might cause lap marks and causes it to be harder to sand and get a easy base to the topcoat. Oil-based primers sand effectively but dry more slowly and gradually (some normally takes http://exterior-painters-charlot68157.full-design.com/exterior-metal-primer-paint-No-Further-a-Mystery-32759997