Which sealer can be used as a primer before painting and help combat bleeds?

Clear Topcoat sealer can be used as an alternative to shellac to seal porous surfaces (like concrete or raw wood) or to prime surfaces prior to painting (great for surfaces susceptible to bleed through or have an odor). We recommend using two thin coats of Clear Topcoat sealer for a full coverage seal. Apply one thin coat of sealer and allow it to dry 24 hours before applying a second coat. Allow sealed surface to cure 72 hours before painting.