Now prime and paint right over cured POR-15 with High Build. This special "interlocking" primer for painting over the top of POR-15 without any need to rough up or de-gloss. High Build Primer is a tough yet sandable single component polyuerthane primer, with special adhestion characteristics that make it perfect for most painted surfaces. It is highly resitant to penetrating topcoats, like lacquers, enamels, two-components finishes not suitable for use with cellulose paints. It sands very smoothly too.