It depends on the type: Epoxy is typically waterproof and does not require any additional sealing layers, while acrylic paint may not be 100 percent water-resistant and can benefit from a sealer coat.

Apply with a natural-bristle paint brush to sanded and cleaned ... Polyurethane, varnish, and lacquer are tried-and-true sealants with excellent waterproofing properties. For best results, apply ...