Primer is not waterproof. No paint is waterproof. All paint has an element of pourosity to it. If left enough then the surface of the primer will break down quicker as it’s not got a reflective coating.Click to see full answer. Regarding this, is primer sealer waterproof?Seal-Krete Original Waterproofing Primer/Sealer penetrates deeply into interior and exterior vertical surfaces to protect concrete or masonry. Versatile, water-based acrylic binds with existing elements to create a tough film that enhances concrete, increases paint adhesion and rejuvenates painted surfaces.Similarly, does primer absorb water? Primer does absorb water. If you want to protect an unseen area from corrosion, use zink chromate spray. Similarly, you may ask, is wood primer waterproof? Primer can reduce the number of paint coats needed for good coverage and even color. A thin layer of paint may still be permeable to water. Water can permeate into the wood and cause warping, mildew, or dry rot. Primer improves the waterproofing of the finish.Do I need primer sealer?Yes a ‘sealer’ is required and yes you’re done because epoxy-primer is the ultimate ‘sealer’.