What is the difference between an exterior and an interior primer?
Primers are designed to prepare surfaces for painting; exterior primers also must withstand harsh weather elements. Alkyd and latex based primers are effective stain blockers and all-around primers for both interior and exterior applications. For exterior application on wood, it’s best to use a top-quality acrylic primer that is recommended for exterior wood. Latex primers work better if the wood is heavy with tannins. Acrylic block fillers are used to prime concrete block. For interior stain-blocking applications, use a latex primer recommended for interior use.
